Yes had a search even on 3si and didnt have the exact answers im after.

Ok, what i am chasing is 100% confirmation that the lower manifold is the same, as well as the CAS, and external sender loom as well, also if that the Alt,SM and AC compressor from a 6g74 all are able to be bolted to the 6g75. Also are the exhaust manifold ports and studs are they the same as well?

Reason for this as since i might be having to get a new motor for the TH might as well put a 3.8l in, but if it will be too much effort then i wont bother.

Also with the coilpacks, would the 6g75 still have the spot for the dissy assembly etc as well?

Yes had a search even on 3si and didnt have the exact answers im after.

Ok, what i am chasing is 100% confirmation that the lower manifold is the same, as well as the CAS, and external sender loom as well, also if that the Alt,SM and AC compressor from a 6g74 all are able to be bolted to the 6g75. Also are the exhaust manifold ports and studs are they the same as well?

Reason for this as since i might be having to get a new motor for the TH might as well put a 3.8l in, but if it will be too much effort then i wont bother.

Also with the coilpacks, would the 6g75 still have the spot for the dissy assembly etc as well?
Not really as the cam would run the dizzy pack, and would be a longer cam too? so this wouldnt have it.....you'd need to run a piggyback ECU to run.

']Not really as the cam would run the dizzy pack, and would be a longer cam too? so this wouldnt have it.....you'd need to run a piggyback ECU to run.

The heads and cam are pretty much the same judging from pictures etc, piggyback aint an issue as ive already got one on the car + one sitting in the shed (picked up a haltech for a ripper price on fleabay ages back)

Reason for this as since i might be having to get a new motor for the TH might as well put a 3.8l in, but if it will be too much effort then i wont bother.



sorry not hijacking, (well i am), just wnat a yes/no answer.

1. are these the motors from newer (o/s model) galants/eclipses, and 380's here?
2. do they bolt straight in?
3. is it diff block or just bored w/ extended lift cam or something?

sorry not hijacking, (well i am), just wnat a yes/no answer.

1. are these the motors from newer (o/s model) galants/eclipses, and 380's here?
2. do they bolt straight in?
3. is it diff block or just bored w/ extended lift cam or something?


1: yes
2: Thats what im trying to find out, ive got one coming anyways (hopefully)
3: From what ive heard same block different bore and stroke same cam/head setup (again its what i heard im trying to find out)

Mate, speak to Caine in Adelaide Mits clearance centre, he has I believe sold one to a guy in SA who has bolted it into a TJ.

I believe all the bits from the 3.5 can be used in the 3.8 and you use the lower manifold off the 3.8, that is what he told me

Mate, speak to Caine in Adelaide Mits clearance centre, he has I believe sold one to a guy in SA who has bolted it into a TJ.

I believe all the bits from the 3.5 can be used in the 3.8 and you use the lower manifold off the 3.8, that is what he told me


Mal,

your a legend cheers

Mate, speak to Caine in Adelaide Mits clearance centre, he has I believe sold one to a guy in SA who has bolted it into a TJ.

I believe all the bits from the 3.5 can be used in the 3.8 and you use the lower manifold off the 3.8, that is what he told me


the 3.8 that caine had there has been sold but hasnt been picked up yet.

edit: the engine loom is defferent due to coil on plug but also because it has different sensors wired up. you could use a 3.8l block with 3.5ltr heads with ralliart cams.

Use all your 6G74 stuff inc lower intake manifold so your return style fuel rail bolts on. So just swap every thing so it looks like a 6G75. You can weld up the throttle body holes on the plenum re-drill and fit 3.5 throttle body and make a new cable. Thats what I've done. If you put the 3.5 sump,pick and dipstick/dipsticktube up on you will need to re-drill a couple of sump bolt holes. For AWD there a couple of bosses on the back of the block that need to be cut of.
Hope this helps the grunts worth it!

Cheers Dave

Forgot LIKE everything, crank sprocket and pick up/ dissy and leads etc I mean everything. Like so you can't tell it's a 6G75 only by looking at the head casting #

Cheers Dave

Use all your 6G74 stuff inc lower intake manifold so your return style fuel rail bolts on. So just swap every thing so it looks like a 6G75. You can weld up the throttle body holes on the plenum re-drill and fit 3.5 throttle body and make a new cable. Thats what I've done. If you put the 3.5 sump,pick and dipstick/dipsticktube up on you will need to re-drill a couple of sump bolt holes. For AWD there a couple of bosses on the back of the block that need to be cut of.
Hope this helps the grunts worth it!

Cheers Dave

upper intake doesnt worry me, as my blower will be bolted there so i will reuse my current TB

Why did you put the 3.5 sump onto the 3.8 for exactly? something didnt line up?

6G75 sump hangs lower than 6G74. 6G74 sump clears extractors and are cars are subject to minimum ride height rule and the sump is lower than the horth south x-member when using 6G75 sump.

Cheers Dave

So Dave, the heads, cams etc are the same on the 74 and 75 engines?

Reason I ask, can you just change your top manifold and rocker covers and have everything else bolt on from the 74 engine.

From what Caine told me, you simply just bolt on all the 74 bits and looking from on top it will simply look like any other 74 engine.
Cheers

Humm are the head gasket numbers the same?

Just doing some readin on the net. Apparently 75 crank fits right into 74, using 1mm+ oversize pistons and something about 2mm wrist pins? gains a total of 3.75L

']Just doing some readin on the net. Apparently 75 crank fits right into 74, using 1mm+ oversize pistons and something about 2mm wrist pins? gains a total of 3.75L

Pulling the motor apart vs just throwing a whole motor in........ i know what one id be doing.

We shall see what its like once i get and fit this new tensioner.

Externally the 74-75 heads are the same so 74 stuff bolts onto the 75. Valves and rockers are different. but cams are the same except the 75 has a groove on the back of the front cam to drive cam angle sensor.
Pretty sure gaskets are different dure to 75's larger bore.

Cheers Dave.

I thought the 75 ran the Ralliart 6G74 cams?

I thought the 75 ran the Ralliart 6G74 cams?

They run the same profile, however the journals are slightly larger on the 380 cams vs the ralliart cams.

right-o. So running the Ralliart cams would give the same result. Wouldn't it be more convenient to adjust what the 74 already has, and increase the throw to do the same job? I think this was being discussed in another thread...

right-o. So running the Ralliart cams would give the same result. Wouldn't it be more convenient to adjust what the 74 already has, and increase the throw to do the same job? I think this was being discussed in another thread...

Not really, as ive read and spoke to a few guys doing this/done it, just swap the lower sump and put the dissy assembly in, and it all bolts in you get a lot more grunt from it like that, and the conversion totall would be about 2k if you purchase the motor at around 1k.

Changing whole motors is far easier then stripping and rebuilding one.

fair enough. Going by some of the gains the 380 guys are getting, it would surely be a sweet motor. It would be fantastic with a blower AND the streetfighter manifold.

fair enough. Going by some of the gains the 380 guys are getting, it would surely be a sweet motor. It would be fantastic with a blower AND the streetfighter manifold.

163kw with basic breathing mods isnt bad i suppose, if this pulley is the only source of my issue then i wont go ahead with the conversion but if it isnt, then its hello 6g75 and Manual Gearbox.

163kW NA through the front wheels would be good enough for me in a car weighing ~1500kg

so from what I've read the basic answer is yes, correct me if i am wrong.

the 380 motor will bolt straight in and all you have to do is swap over all wiring, intake manifold,sump, injectors and put the original magna distributor in?
basically all the external stuff.

so from what I've read the basic answer is yes, correct me if i am wrong.

the 380 motor will bolt straight in and all you have to do is swap over all wiring, intake manifold,sump, injectors and put the original magna distributor in?
basically all the external stuff.

no wiring swapping afaik, some senders are slightly different but you can cut and shut them, yes about manifold and sump, injectors just leave the 380 ones in there they work fine with the 3.5 ecu from what i have heard (some dude with a sprintex has them in his car and runs fine)

All the acc's bolt straight on afaik, and the other block is all the same.

163kw is what im making atm with the blower, but with a lot more torques, so probably 220-230kwish with a blower on a 3.8 (depending on exhaust etc etc)

so you can't swap the senders over from the 3.5 onto the 3.8?

so you can't swap the senders over from the 3.5 onto the 3.8?

TBH i dont know, and if i do this conversion i wont bother, worse case they will be bullet fittings instead of the spade which is a 5sec job to change over anyways.

personally i would rather change the sensors over from the 3.5 onto the 3.8 to suit the wiring rather than changing the wiring to suit the motor. but if it's the only way to go then that the way it has to be.

You may need larger injectors as well if supercharging.

why wouldnt you put the 380 engine in + with a full aftermarket ecu or piggyback for maximum gains, saves doing it half assed / stuffing around

why wouldnt you put the 380 engine in + with a full aftermarket ecu or piggyback for maximum gains, saves doing it half assed / stuffing around

Because it will be going on with the SMT6 thats why. For the blowersssssssssss

And no zero stock injectors are fine, sprintex is designed to run with the standard 3.5l injectors so the 3.8 ones are more them ample.

If you put the 380 engine in with your blower I will have a 380 tuned SMT-6 if you're interested.

so probably 220-230kwish with a blower on a 3.8 (depending on exhaust etc etc)
There's a 230kw atw 380 getting around so that is your benchmark, I'm hoping I might be able to squeeze a little more :badgrin:

There's a 230kw atw 380 getting around so that is your benchmark, I'm hoping I might be able to squeeze a little more :badgrin:

if i slapped my blower on there with some HW and possibly larger cam and some vernie+ big zorst i could get 250ish maybe.

if i slapped my blower on there with some HW and possibly larger cam and some vernie+ big zorst i could get 250ish maybe.
Not good enough, we need doers! do it!

I'm in the process of doing it although it doesn't involve an engine change for me lol

']Not good enough, we need doers! do it!

Will know by tomorrow if AAE pull the gigantic giant long thing named a (insert bad word here) and actually put my pulley in a spot where i can pick the bastard up instead of making poor excuses.

If i put it on and its still playing up, ill be picking up the keys to a 380 halfcut on sunday.

Use all your 6G74 stuff inc lower intake manifold so your return style fuel rail bolts on. So just swap every thing so it looks like a 6G75. You can weld up the throttle body holes on the plenum re-drill and fit 3.5 throttle body and make a new cable. Thats what I've done. If you put the 3.5 sump,pick and dipstick/dipsticktube up on you will need to re-drill a couple of sump bolt holes. For AWD there a couple of bosses on the back of the block that need to be cut of.
Hope this helps the grunts worth it!

Cheers Dave

Dave, what bosses exactly have to be hacked off the 6G75 engine to to clear in the AWD? Sounds like you have already done the conversion so it will save mucking about if us AWD guys can just cut the bosses and drop the 3.8 straight in and not have to waste time lifting it in and out a few times to get bits cut off for clearance.

Sounds like you left the 380 plenum as it is with the bend in the entry after the throttle body. Are you running the stock intake pipes from the AFM/air box?

Graham Bell has just started assessing a 6G75 and he told me the big improvement is in the heads. The main ports are still too big but the bifurcated ports are pretty good, maybe a bit small for the big valves but a good size for bottom end HP. He measured the inlet valves as being 36.4 mm and the exhausts 32 mm so thats a lot better than the 6G74's tiny 33mm and 29mm valves. The combustion chambers have volumes around 65cc and 94mm across so they could be fitted to a 3.5 bottom end, but if anyone decided to do that they would need flat top pistons to get anywhere near a reasonable compression ratio. The 3.8 pistons are flat tops with a low double tier intruder (he hasn't measured them yet but says they look to be about 0.3-0.4 mm each tier) so should be nice and light too. When he gets more measuring done and sends me some photos I'll post them up.

Cheers, Alan

Hey Alan, The bolt bosses are near the rear off the block there are 2 in the way off the right angle drive. Think there for maybe pajero with north south installation. We didn't know there was a difference untill we had installed it just cut the 2 bosses off with an angle grinder. the 3.5 doesn't have them so if you had them side by side you'ed spot the difference. Yeah the heads were along over due upgrade for the S4's they should of had a valve size ungrade at 3.5 but you know the cost thing.

Cheers Dave.

From what I've been reading on the 3000GT forums, these 75 heads flow better then stage 3 74 heads.:shock:

Sorry Alan, your other question yes we run the 380 plenum liked the extra plenum volume and the larger radius on the runner entries. Also fitted the 380 butterfly in to the 3.5 throttle body (65 v's 68) and hand blended throttle body an plenum entry. Yes we use a std intake system only the air box is upside down, battery is re-located and the cut down original snorkle faces the head light and an extra duct (75mm) is fitted to the air box getting air from the front grill in the bottom of the bumper. Did some tests on the dyno with straighter ducting no filter, no air box, pulled A/F meter up over the radiator etc no gains to be found. We are currently making 222kw's at the front wheels.

Cheers Dave.

Alan, Zero took some photos of the intakes and cars. Search Mallala under South Australian section.

Cheers Dave.

So do you have to use a 3.5 sump like you do on the fwd's? oops, reckon thats a yes.

OK thanks for that info Dave.

What cams and valve springs are you running in your track 3.8?

Are you using stock pistons and rods with ARP bolts? What sort of rpm are they safe for? Mitsubishi lowered the cut out from 6900 rpm to 6200 on the 3.8 even though the piston is a flat top, so presumably lighter than 3.5 6G74, and the small increase in stroke shouldn't have had much effect. Do you have any insights as to why the 700 rpm reduction?

Cheers, Alan

Hey Alan, The bolt bosses are near the rear off the block there are 2 in the way off the right angle drive. Think there for maybe pajero with north south installation. We didn't know there was a difference untill we had installed it just cut the 2 bosses off with an angle grinder. the 3.5 doesn't have them so if you had them side by side you'ed spot the difference. Yeah the heads were along over due upgrade for the S4's they should of had a valve size ungrade at 3.5 but you know the cost thing.

Cheers Dave.

The thing is Dave, ive never had any problems with getting the 3.5L heads to flow alot of CFM and make big horsepower with the stock 3.5L valve sizes (for NA builds).

For turbo/SC engines id definately fit bigger valves though but then thats common sense lol

Alan, so many questions, Stock, stock, stock & stock it's all good we are only messing around with cam profiles.We use 6800 rev limit the original 3.8 limit. There was a story from Japan that a 3.8 S4 Paj engine had a crank failure sitting on the rev limiter with no load for a fair while so after the hub failure drama they dropped 600 rpm. We never trust the japs, they always cover stuff up when it suits them.
Jason, yes modded heads do make excellent house power and (flow numbers beyond what we can lift the valve) but it's not cost effective from a production stand point. As for the bigger valves in a blown engine? Well they will like it just as much as a N/A engine would, with just a bit more exhaust flow.

Cheers Dave.

Are you guys running deleted AC and PS steering setups aswell?

OK thanks again Dave. Sorry for all the questions, but thats the way to learn, even for old guys!

Thats pretty impressive HP you are getting then with stock cams. I was thinking you must have had something bigger.

Good to get the inside story on the lower rev limit too. Are you having any issues running to 6800rpm with the skinny rods and stock pistons? are the big ends staying round and not nipping bearings?

Jason the reason big valves work so much better is not so much for high lift flow but for very much better flows at low lift so you can run a very mild cam and still get the same top end HP and pick up bottom end and mid range. Or if you want more top end you can get that too and still keep the same bottom end torque. From what Graham has told me in the last few days since he started pulling his 3.8 down the 380 engine should have been making about 210kw. Why was it only advertised at 175kw? Was the 380 exhaust so much more restrictive than the later Magna VR and VR-X? Was it the Euro III emissions tune?

Cheers, Alan

For someone like me with little to no knowledge of engines, this is a great read! So many people, with so much info to share :)

Hey Alan ,Dave's cams are'nt stock.

OK thanks again Dave. Sorry for all the questions, but thats the way to learn, even for old guys!

Thats pretty impressive HP you are getting then with stock cams. I was thinking you must have had something bigger.

Good to get the inside story on the lower rev limit too. Are you having any issues running to 6800rpm with the skinny rods and stock pistons? are the big ends staying round and not nipping bearings?

Jason the reason big valves work so much better is not so much for high lift flow but for very much better flows at low lift so you can run a very mild cam and still get the same top end HP and pick up bottom end and mid range. Or if you want more top end you can get that too and still keep the same bottom end torque. From what Graham has told me in the last few days since he started pulling his 3.8 down the 380 engine should have been making about 210kw. Why was it only advertised at 175kw? Was the 380 exhaust so much more restrictive than the later Magna VR and VR-X? Was it the Euro III emissions tune?

Cheers, Alan

Alan there is nothing wrong with the flow rate of my 3.5L heads with "stock" valve sizes at 100thou, 200thou, 300thou, 400thou and 500thou lift. My good mate who flows my heads on his flowbench said that the heads ive been doing are pretty bloody good and compare very well to the worked "2.5Neo" nissan 6cylinder heads that he uses on the drift 2.5/3.0L engines that he builds.
Ive never had any driveablity issues with any of my 3.5's that ive built, they have been quite nice streetable engines. The cams are a big deciding factor in getting the grunt where we want it and both my "big" build engine and Dave's race engines use the same spec cams except mine are running 106deg lobe centres compared to his 108deg

Also Allan the 380's ran 3 cat convertors, one up high on the manifolds on each head and then the third underneath in the usual spot, this setup is known to be very restrictive to top end power (this was also the reason the 2000 onwards california spec 3.5 NAS diamantes fell very flat in there top end power delivery)

am i correct i thinking that going from 99 TH 3.0L 6G72 to the 6G75 will be no different?

will the TH 3.0L ECU handle the 6G75 or will i need to upgrade to the TJ ECU?

OK Jason I may not have explained correctly re the comparatively small 33mm inlet valves in the 6G72 and 6G74 engines. For their size they can be made to flow reasonably well but remember the Nissan 2.5/3.0 has small 86mm bore that limits valve size, and the Yamaha headed Toyota 1JZ/2JZ is in the same position due to the small bore, so in spite of it having an excellent head(much superior to the over-rated Nissan) its potential is ultimately limited because eventually you get a flow restriction. Then the only option for more HP in N/A form is a bigger cam.

The point I was trying to make is that the 3.8 ltr 6G75 should be capable of a lot more flow at low lift so you can run with a smaller cam and make more power over a bigger rpm range. The other advantage of bigger valves is that you don't have to spend a lot of time and money enlarging the ports for good high lift flow. On the early heads Graham reckons he spends about a day porting for each cylinder. Thats filling them in places and grinding them in other places. That is a lot of money! He's only just broken the 6G75 open but from first appearances reckons the stock ports in the 6G75 will flow better with minimal work, probably less than a day per head. When he gets a head on the bench he'll give me the numbers and I'll pass them on.

Low lift flow, up to about 0.2-0.27", is all about valve circumference. High lift flow is more port size and shape. The 6G75 has two valves 36.4mm dia. In area thats the same as a single 51.48mm valve(2.02" like a small block Chev), but air doesn't flow through the valve, it flows out the edges. So at 1mm lift the 2 x 36.4 mm valves have a flow window thats 1mm high and 228.7mm long(thats valve dia x pi x 2). Thats equal to a port 15.1mm x 15.1mm. The single big valve by comparison has a tiny flow window of 1mm x 161.7mm. Equal to a port 15.1 wide but only 11mm high, so the 3.8 engine has over 41% more flow area around the valve than the small block Chev at all valve lifts. The 6G72/74 heads have a flow window thats nowhere near as small as the single valve Chev's, at 1mm lift it will be 1mm x 207.3mm, about equal to a port 15.1mm x 13.7mm, just over 10% smaller than the 6G75, but 28% better than the Chev.

Regarding the cams you and Dave run what are the specs? Do you know the durations at the valve @ 0.075", 0.150" and 0.300" please? and what lift?

Cheers, Alan

Bloody hell, six days of porting sounds like a waste of money for what we want, unless you're doing it for yourself.

OK Jason I may not have explained correctly re the comparatively small 33mm inlet valves in the 6G72 and 6G74 engines. For their size they can be made to flow reasonably well but remember the Nissan 2.5/3.0 has small 86mm bore that limits valve size, and the Yamaha headed Toyota 1JZ/2JZ is in the same position due to the small bore, so in spite of it having an excellent head(much superior to the over-rated Nissan) its potential is ultimately limited because eventually you get a flow restriction. Then the only option for more HP in N/A form is a bigger cam.

The point I was trying to make is that the 3.8 ltr 6G75 should be capable of a lot more flow at low lift so you can run with a smaller cam and make more power over a bigger rpm range. The other advantage of bigger valves is that you don't have to spend a lot of time and money enlarging the ports for good high lift flow. On the early heads Graham reckons he spends about a day porting for each cylinder. Thats filling them in places and grinding them in other places. That is a lot of money! He's only just broken the 6G75 open but from first appearances reckons the stock ports in the 6G75 will flow better with minimal work, probably less than a day per head. When he gets a head on the bench he'll give me the numbers and I'll pass them on.

Low lift flow, up to about 0.2-0.27", is all about valve circumference. High lift flow is more port size and shape. The 6G75 has two valves 36.4mm dia. In area thats the same as a single 51.48mm valve(2.02" like a small block Chev), but air doesn't flow through the valve, it flows out the edges. So at 1mm lift the 2 x 36.4 mm valves have a flow window thats 1mm high and 228.7mm long(thats valve dia x pi x 2). Thats equal to a port 15.1mm x 15.1mm. The single big valve by comparison has a tiny flow window of 1mm x 161.7mm. Equal to a port 15.1 wide but only 11mm high, so the 3.8 engine has over 41% more flow area around the valve than the small block Chev at all valve lifts. The 6G72/74 heads have a flow window thats nowhere near as small as the single valve Chev's, at 1mm lift it will be 1mm x 207.3mm, about equal to a port 15.1mm x 13.7mm, just over 10% smaller than the 6G75, but 28% better than the Chev.

Regarding the cams you and Dave run what are the specs? Do you know the durations at the valve @ 0.075", 0.150" and 0.300" please? and what lift?

Cheers, Alan

Well comparing the stock 3.8 head and 3.5 head that i have in my shed there is SFA difference in the ports the biggest difference is the more "open" combustion chamber on the 3.8 head, and guess what.... thats where most of the head work has been done on all my 3.5 heads. The ralliart heads had a minor opening up (deshoruding) of this area around the valve head in the combustion chamber, on my heads that whole chunk is virtually taken out and looks very similar to the 3.8 chamber (all chambers on my heads are "CC'd" as well) also there wasnt much work needed in the ports to get the results i wanted.

At the end of the day there is no point in having heads that flow a million HP, when the aim for my motors was/is only around 400hp in NA form lol

Im happy with the heads ive done "myself" (cost me stuff all) and saw no need to add 3mm bigger valves (also because i had a full set of brand new valves etc to do my last set of heads) to achieve bugger all when i had always intended to run some nice large cams.

In regards to the chev comparo even my one eyed holden/chev race engine building uncle has commented on how damn good the 4valve magna head is, as well as the 3.5L crank and "thick 74" rods are :P And he doesnt normally say good things about non GM products.

Bloody hell, six days of porting sounds like a waste of money for what we want, unless you're doing it for yourself.

Spot on there Al :)

Anyway im gunna shut up now and if Dave TJ wants to disclose the specs of the cams we run then he can but i dont feel like letting all the "secrets" out on a public forum, especially considering the massive stuffing around ive had with the cam maker/grinder :rant:

Spot on there Al :)

Anyway im gunna shut up now and if Dave TJ wants to disclose the specs of the cams we run then he can but i dont feel like letting all the "secrets" out on a public forum, especially considering the massive stuffing around ive had with the cam maker/grinder :rant:


LOL would you tell me? so i can do the same!! haha:badgrin:

Alan, stoke rods are OK so far and I don't see a problem in the future. I do worry about the pistons most of our engines have early non production pistons. The production pistons were beefed up around the pin boss area after a couple of failure in the over rev test. I think production ones would be OK for most N/A applications.
The 380 main bearing are cheap and tight we had some problems early on when racing them so we switched straight back to 3.5 mains, MMAL never had a problem with mains on 3.5's and we've had no further issues. I would strongly recommend this change for anyone considering leaning on a 6G75. We looked at the bearings and it just stank of the usual costdown programs that manufacturers do.
Before Euro 3 we ran 6G75's on the previous spec and had a solid 182 kw's, I think 200 might have been in reach with the Ralliart prototype cam and it would of passed the idle quality too. The 3 cats did hurt the power for sure then we found we realy only needed the 2 close coupled cats and could of lost the UCC but it was to late for Bosch to recalibrate the ECU (money). Thats what happens when you out souce your calibration on a costdown theory and then lose indepedance. We got screwed. Then we couldn't pass the drive by noise, to much induction noise, so some jap chuched a 2.4 ltr front duct onthe air box killed a good 3 kw's hey but it passed. It was an 11th hour bandaid.
Cam profiles Alan, tell me what Graham thinks. I see the problem as we have 2 very different requirements 1) a traction limited FWD and 2) A non traction limited heavy AWD. So 2 different camshaft requirement.

Cheers Dave

At the end of the day there is no point in having heads that flow a million HP, when the aim for my motors was/is only around 400hp in NA form lol


Are you going down the route of individual throttle bodies to achieve this much power NA?

Are you going down the route of individual throttle bodies to achieve this much power NA?

Nope. I might add that 400hp is the flywheel output that i wanna achieve this time again.

damn impressive on a 3.5 V6 thats for sure!

After hearing BJ31OS's car on the weekend, it sounds lumpy as hell and so cool. That was the first time I had heard a 6G74 with lumpy cams

damn impressive on a 3.5 V6 thats for sure!

After hearing BJ31OS's car on the weekend, it sounds lumpy as hell and so cool. That was the first time I had heard a 6G74 with lumpy cams
His is a 6G72

damn impressive on a 3.5 V6 thats for sure!

After hearing BJ31OS's car on the weekend, it sounds lumpy as hell and so cool. That was the first time I had heard a 6G74 with lumpy cams

And his cams are mild ones :P

']His is a 6G72

aaaaah of course its a 3.0, silly me. Well it sounded great all the same. Shame it is broken :(

aaaaah of course its a 3.0, silly me. Well it sounded great all the same. Shame it is broken :(
The engine isn't broken it's just the gearbox going into limp mode all the time last I heard the engine was going strong.

problems with the MAF and/or wiring i think. Should be easy to fix.

Bloody hell, six days of porting sounds like a waste of money for what we want, unless you're doing it for yourself.

But on the other hand....maybe i was forgetting a couple of things like passion and commitment. :redface:

are the big ends staying round and not nipping bearings?


:bowrofl: :cry: I wish. That was the skinnys in a 6G74. Thanks MMAL!

Sorry Ian, Tend to think your bearing problem was an oiling supply issue. Not the rods fault. Hey thats only my opinion.

Cheers Dave.

Sorry Ian, Tend to think your bearing problem was an oiling supply issue. Not the rods fault. Hey thats only my opinion.

Cheers Dave.

Here's hoping the entire issue is well behind me! Likely that Castrol Edge was the kill shot but shouldn't the mains have gone first? There was no marks on them at but 1x spun big end bearing and another with a very suspect marking from a pinch I guess. Weird.

Here's a link to my findings with the rods: http://www.aussiemagna.com/forums/showthread.php?t=64967

Ian. Hardest working bearing is the last on the supply line so it's the 1st to get starved and fail. Baffle? Best of luck this time fella.

Cheers Dave.

I love this tread.

If only it was about going from a 3.0L to a 3.8 then id be the happiest kid alive.

looks a little more complicated going from 3 to 3.8......

I love this tread.

If only it was about going from a 3.0L to a 3.8 then id be the happiest kid alive.

looks a little more complicated going from 3 to 3.8......

how is that so??

from what i have read its no different form 3.0L to 3.8 as to 3.5 to 3.8

please correct me if im wrong as im about to buy a 3.8l motor

Im probally wrong but would all the 3.0L stuff bolt onto the 3.8L as easily as the 3.5L stuff?

most of it bolts on the 3.5 without any issues, so cant see why not.



do it!!!

Looks like i better start looking for a 3.8

3.8 all the way you won't regret it. Like they say there ain't no replacement for displacement.

Cheers Dave.

OK Dave thanks for the update on 6G75 factory development. Sorry for late response, I've tripped over to the coast to see my old buddy last week as hes crook and haven't been near the computer until just now.

Had a look inside the 6G75 and see lots of potential just as Graham does. One thing he mentioned was that the cam lobes are Ralliart as you stated previously but due to the changed geometry in the 3.8 the inlet action is slightly milder at the valve by about 3 deg at all significant points, and the ex is about 4-5 deg longer if I remember him correctly. He thought it may have been Jap grinding but when we swapped the 3.8 cam into a 3.5 head at the valve event measured the same as his unused Ralliarts. He noted that the manual on CD is wrong. The cam journal diameters are the same as the earlier 3.0 and 3.5 ltr so the cams can be interchanged. (manual states journal are 45mm, but are actually 44.93; and the inlet lobe height it gives is incorrect too).

Rear cam was ground on 108.25 separation and front cam on 111.75 deg. What was the thinking behind that? Graham suggested idle quality, something to help a HVH issue or some undesirable harmonic. Both cams are retarded 6.4 deg.

How did oil consumption and cylinder wear compare between the 3.8 and 3.5? This 3.8 looks very "wet" but may not be typical, and the lower half of the cylinder is worn through the hone marks in 60,000km. Top of cylinder looks good though with ring line just becoming visible through the hone.

Regarding your cam specs Graham is only looking at doing short duration mild road cams to pick up the AWDs and autos. I only asked the question regarding your cams to get an idea of how much cam you needed to make the power you quoted. No offense was intended.

Cheers,
Alan

Hey Alan, No offence taken, would be keen on someone else's thought on the subject.
Yeah that sounds similar to what I found 3 degrees less on the inlet. exhaust was pretty much the same and less lift on both. I put it down to the valve repositioning and rocker arm change.
The lobe seperation difference seems to be on all the v6 mitsi cams to a different degree from what I gather it's machining problem with the leading, trailing rocker arm senario. From the material I've read they are looking for equal lobe seperations, but I'm not positive as I've said before the Japs never tell you everything.
6 degress retard is the correct setting for the 380 camshaft.
Just my feeling would be to get as much lift as practical and around an extra 15-20 degress duration and 110 lobe seperation for a road car should do it. Give me your thoughts, I like to hear your ideas.

Cheers Dave.

Thanks Dave, I haven't really got into thinking about cams as it seems a big problem to get them done reliably. Except for that very suspect source good cams are not available it seems.

Graham hasn't been put off though and is having masters done at the moment for a mild road cam. Not sure of the exact specs but I think he said the inlet was about 200 deg, or maybe a bit less at 0.050", and just over 100 deg at 0.200", with nearly 11mm valve lift. I know he had bee-hive ovate wire springs made to handle the lift. Not sure about the exhaust lobe specs but he wants to try for 108 deg lobe separation on both cams if he can fit it on the stock front cam without excessive material loss. The other issue will be getting a suitable heat treat after grinding. From what I gather he thinks the exhaust side of the head is quite good so doesn't need much cam to get the job done, so that lobe won't be much bigger than the Ralliart/380 ex.

Earlier you mentioned the development Ralliart cam. How did that compare with the final production Ralliart? Same lift and more duration I suspect?

We both prefer to use a little cam as possible and focus on getting the head working. 4 valve heads are not like the inefficient American iron that most tuners have to deal with so the cam can be very short duration, but good lift within reliability limitations. Then you get plenty of low rpm HP off and on throttle, and better than stock fuel economy driven sensibly. That is where the 3.8 heads are going to be such a help with their bigger inlet valves. Also with the big valves you can drop port size, as well as cam duration, and still keep the top end HP. Thats not to say big valves are everything but when they are there for the taking in a relatively good head like the 3.8 then go for it.

About early-90s we were doing engines for DTM touring car championship, 2.5 ltr V6 with 12,000rpm limit. They were making nearly 530HP by 1996 and would pull from only 4,500rpm. We could use air springs so the cams were a lot more radical with faster opening and closing ramps than you can get away with using wire but that said the duration was less than 270 deg at the seat and lift was approaching 16mm. The big HP was possible with cams not much more radical than the factory cam in many current V8s because of the great heads on these engines with straight shot ports and 2 x 38mm inlets and 2 x 32mm ex. valves.

Cheers,
Alan

Thanks Dave, I haven't really got into thinking about cams as it seems a big problem to get them done reliably. Except for that very suspect source good cams are not available it seems.

Graham hasn't been put off though and is having masters done at the moment for a mild road cam. Not sure of the exact specs but I think he said the inlet was about 200 deg, or maybe a bit less at 0.050", and just over 100 deg at 0.200", with nearly 11mm valve lift. I know he had bee-hive ovate wire springs made to handle the lift. Not sure about the exhaust lobe specs but he wants to try for 108 deg lobe separation on both cams if he can fit it on the stock front cam without excessive material loss. The other issue will be getting a suitable heat treat after grinding. From what I gather he thinks the exhaust side of the head is quite good so doesn't need much cam to get the job done, so that lobe won't be much bigger than the Ralliart/380 ex.

Earlier you mentioned the development Ralliart cam. How did that compare with the final production Ralliart? Same lift and more duration I suspect?

We both prefer to use a little cam as possible and focus on getting the head working. 4 valve heads are not like the inefficient American iron that most tuners have to deal with so the cam can be very short duration, but good lift within reliability limitations. Then you get plenty of low rpm HP off and on throttle, and better than stock fuel economy driven sensibly. That is where the 3.8 heads are going to be such a help with their bigger inlet valves. Also with the big valves you can drop port size, as well as cam duration, and still keep the top end HP. Thats not to say big valves are everything but when they are there for the taking in a relatively good head like the 3.8 then go for it.

About early-90s we were doing engines for DTM touring car championship, 2.5 ltr V6 with 12,000rpm limit. They were making nearly 530HP by 1996 and would pull from only 4,500rpm. We could use air springs so the cams were a lot more radical with faster opening and closing ramps than you can get away with using wire but that said the duration was less than 270 deg at the seat and lift was approaching 16mm. The big HP was possible with cams not much more radical than the factory cam in many current V8s because of the great heads on these engines with straight shot ports and 2 x 38mm inlets and 2 x 32mm ex. valves.

Cheers,
Alan

I have a set of the prototype cams (from prototype engine number 2) sitting home, they have more duration (around the 260? total duration) and approx .4mm more (so 1.5mm more lift than stock TJ cams) lift than the official ralliart sticks. As for exact specs well im not sure, im sure Dave TJ or Rod would know more about them and no they arnt for sale.

Hello guys, Alan 11mm lift sounds good, going the notched cam tunnel. I think it's the way to go the inlet valve really gets cooking up there. I just can't find people to do it. Proto Ralliart had a bit more duration @ 050" than your talking but only 9.8mm lift in 3.5, 9.75mm lift in 3.8. The factory target was 9.9mm but they worried about fittment speed of the camshaft on the production line. So I think the Figures Graham is talking would be excellent for AWD.
Yes 3.8 always had higher oil consumption than 3.5 on the capacity scale usage but still in MMC spec with much higher blowby figure. MMC changed rings, bore finishes and bore wall thickness but like I said we never were told much in the test area even the engineers didn't seem to now there would be be just a quick fit these ring to the next batch or hang on the new block is coming. My usual comment smell cost down. The very thin and tight ring pack to help emissions were the probably a big problem with trying to costdown at the same time Mitsi's back was against the wall. I think thats why the Japs closed ranks plus MMAL went with Bosch mangememt and that **** the Japs right off. You can imagine a Mitsubishi plant choosing the Germans over the Mitsubishi owned MELCO system we were on the out from that moment on. So the information never flowed freely after that.

OK thanks again for the info Dave and Jason, development insights are always interesting and can save time and money waste for tuners/modifiers heading in a direction that has already proved of little value or detrimental to performance or reliability.

I think Graham is initially going for cams with reduced base circle. If they do what hes looking for, and there's no guarantee of that, numbers on paper can always look a lot better than reality, then he will probably explore the benefits of closer to stock 32mm base circle and a notched, or he did mention a bigger dia tunnel. He prefers a big journal, big base circle cam to really push the valve acceleration and keep the duration short.

Was the Ralliart cam design work and grinding done in house? Other Australian manufacturers always got George Wade to do that work but George would have been dead before the time of the Ralliart Magna.

One thing he asked me to run past you guys was why the Ralliart had so much deshrouding around the exhaust valve? I haven't seen a Ralliart chamber but Graham is curious about the ex deshrouding. He has speculated that it didn't hurt and was done mainly to open the chamber to lower the comp ratio for 91RON.

Cheers,
Alan

After serious deshrouding of my 6G74 heads I assure you that it is time VERY WELL SPENT! The motor is very responsive, has loads of torque and goes bezerk from 3300 to redline. Fuel economy has improved over 1.4L/100. Yes the downside is lost compression but that was my plan with 10:1 forgies installed and upto 14psi boost planned. Currect static compression is in the 8.7-8.8 ballpark.

Alan the camshafts were done in house using a factory profile as a base. I think the machine is a toyoda computer controlled grinder. Wades use to do the Hemi 6 cylinder development cams in the 70's for the 6 packs.
I think the exhaust was unshrouded to keep the inlet/exhaust flow ratio similar to the standard head. The piston was done after camber unshrouding, yes comp was kept low for 91 ron. It was an ACL piston with an anodized top ring groove.
I like the idea of a slightly reduced base circle with a bigger journal that would keep the rocker geometry good, it sounds expensive now and we run on alot tighter budget than that. Good luck with it though guys.
Maybe talk with Clive Stenlake from Clive cams (I think in NSW) he worked for Wades for many years, he weld up grind back cams for the 1UZ-FE 32 valve V8 Toyota so he might do a V6 Mitsi. I tried Wades and a couple of others but there not doing anything yet. I'd speak to Dean Tighe he was very helpful with our cam development for the racecars.

Cheers Dave.

Alan the camshafts were done in house using a factory profile as a base. I think the machine is a toyoda computer controlled grinder. Wades use to do the Hemi 6 cylinder development cams in the 70's for the 6 packs.
I think the exhaust was unshrouded to keep the inlet/exhaust flow ratio similar to the standard head. The piston was done after camber unshrouding, yes comp was kept low for 91 ron. It was an ACL piston with an anodized top ring groove.
I like the idea of a slightly reduced base circle with a bigger journal that would keep the rocker geometry good, it sounds expensive now and we run on alot tighter budget than that. Good luck with it though guys.
Maybe talk with Clive Stenlake from Clive cams (I think in NSW) he worked for Wades for many years, he weld up grind back cams for the 1UZ-FE 32 valve V8 Toyota so he might do a V6 Mitsi. I tried Wades and a couple of others but there not doing anything yet. I'd speak to Dean Tighe he was very helpful with our cam development for the racecars.
Cheers Dave.

Just a pitty he cant grind a good turd though Dave, actually thats probably one thing he could do .

As you know after the countless ****** ups he did on my cams over the course of 2 yrs, he gets no recomendations from me and the customer service after the last stuff up....well id love to fly up there and stick the camshafts right up his a**e :io:

Thanks again Dave for your input. Unfortunately welding is not a good long term solution with roller cams as the roller contact loads are too high and the hardface flakes from the base material, plus there can be issues with roller skidding. Welded cams can be useful for a few quick dyno pulls during development though to save on costs.

The V8 Toyota has inverted buckets if I remember correctly? So welded lobes would be OK.

Cheers,
Alan

Just a pitty he cant grind a good turd though Dave, actually thats probably one thing he could do .

As you know after the countless ****** ups he did on my cams over the course of 2 yrs, he gets no recomendations from me and the customer service after the last stuff up....well id love to fly up there and stick the camshafts right up his a**e :io:

i finally got my refund this week after 4 months of arguing

btw they slugged me a 25% restocking fee because they were a custom grind, even though the lobes were rusty when they arrived. myself and another well respected forum member were disgusted that a company would post cams wrapped in cardboard, NO PLASTIC OR OIL TO BE SEEN.

no recommendation from me either

Yes Jason I don't know Dean but Graham went to Qld to see Dean face to face when he began this project. He wasn't impressed at all. Dean admitted he had never seen a 6G engine, didn't know rocker ratios, rocker offsets from cam centerline etc,etc. When asked how he "manufactured" his cam timing and lift numbers he said they were the product of Cam Doctor and that his profiles were mainly modified factory profiles from the end pivot center roller EVO engine. Graham offered to do the calculations for making masters but Dean had no idea of how to grind a master from a 360 deg list of radii.

Cheers,
Alan

Yes Jason I don't know Dean but Graham went to Qld to see Dean face to face when he began this project. He wasn't impressed at all. Dean admitted he had never seen a 6G engine, didn't know rocker ratios, rocker offsets from cam centerline etc,etc. When asked how he "manufactured" his cam timing and lift numbers he said they were the product of Cam Doctor and that his profiles were mainly modified factory profiles from the end pivot center roller EVO engine. Graham offered to do the calculations for making masters but Dean had no idea of how to grind a master from a 360 deg list of radii.

Cheers,
Alan

You got it Alan BUT dean has seen a 6G74 engine, as a guy (chaddy74/Levi) on here took his to Tighe to set up some cams, so once again Dean is talking crap.....

You got it Alan BUT dean has seen a 6G74 engine, as a guy (chaddy74/Levi) on here took his to Tighe to set up some cams, so once again Dean is talking crap.....

How recent was that? Graham made a special trip to see Dean face to face as other methods weren't working to his liking. Dean's emails made the right noises but seemed sus when the hard questions were put to him. Graham went to see him probably about July/Aug 08 to see if his suspicions were founded before he started handing over big $$$. I remember he was most unimpressed.

Cheers,
Alan

This may be off topic a bit, but what would be the place of choice to send some cams to to get re-ground?

You got it Alan BUT dean has seen a 6G74 engine, as a guy (chaddy74/Levi) on here took his to Tighe to set up some cams, so once again Dean is talking crap.....

Graham went up BEFORE chaddy had taken the motor over, about a months difference I recall. Yeah, G was left bewildered after that face-to-face. I told him I'd go him halves in a grinding station; or we could steal Dean's side grinder, a bottle of whisky and have a shot at cutting our own cams - it works for some as people keep ordering them :nuts:

Those so-called "custom" grinds appeared to be a set that were at least 6-12months old given the lobe rust development, my money was on them being a set that Jason or another customer had rejected and were thrown hastily at the next willing customer as a means to an end for them. My opinion.

Alan we started speaking to Dean after that. We sent a set of our cams to him so there was no confusion, check it in you measurements, not ours which he did first suggest. We weren't confident that would work, sending the cams I think was the best thing to do. I pretty sure it helped him, we also told him peak torque/power rpm and were we wanted it to be shifted to and we got very close to what we wanted. Ok he couldn't give us the lift we wanted but he did tell us. The cams had the same lobe seperation problem as the standard cams, When I asked his response was it was in the sample set so we left it in thinking it was a factory necessity. When the next set of cams were ordered I specified a lobe seperation angle the same for both banks and it was done.
Hey these are just my finding, what i'm try to say is this company seems to be the only guys grinding 6G/S4 cams?shouldn't we work with them instead of bagging them, feedback is very important. Remember how many dreamers the cam man speaks to each day, probably 25% less than the performance engine builder speaks to, have a think about it. You'd be supprised. Always have good data, I'm just as guilty, I used 3.5 data without checking in a 3.8 before I sent cams. Totally my fault and how did that help the cam grinder? Yeah $#@^ all you got it, who's fault? mine and mine only thats what happens when you rush and get excited, it's the most common mistake.
Sorry Alan wasn't sure if they could heat treat the re-weld after grinding so it could be used with a roller, have used a few of Wades bucket re-weld cams and had no probs, thanks for that.

Cheers Dave

Alan we started speaking to Dean after that. We sent a set of our cams to him so there was no confusion, check it in you measurements, not ours which he did first suggest. We weren't confident that would work, sending the cams I think was the best thing to do. I pretty sure it helped him, we also told him peak torque/power rpm and were we wanted it to be shifted to and we got very close to what we wanted. Ok he couldn't give us the lift we wanted but he did tell us. The cams had the same lobe seperation problem as the standard cams, When I asked his response was it was in the sample set so we left it in thinking it was a factory necessity. When the next set of cams were ordered I specified a lobe seperation angle the same for both banks and it was done.
Hey these are just my finding, what i'm try to say is this company seems to be the only guys grinding 6G/S4 cams?shouldn't we work with them instead of bagging them, feedback is very important. Remember how many dreamers the cam man speaks to each day, probably 25% less than the performance engine builder speaks to, have a think about it. You'd be supprised. Always have good data, I'm just as guilty, I used 3.5 data without checking in a 3.8 before I sent cams. Totally my fault and how did that help the cam grinder? Yeah $#@^ all you got it, who's fault? mine and mine only thats what happens when you rush and get excited, it's the most common mistake.
Sorry Alan wasn't sure if they could heat treat the re-weld after grinding so it could be used with a roller, have used a few of Wades bucket re-weld cams and had no probs, thanks for that.

Cheers Dave

Dave, i sent 3 sets of cams to Tighe back in March 2007 (which was when i took my car off the road to do the "big" HP build up). One set were the "4" TH cams, one set were "6" TJ cams and the third set were TJ ralliart cams. They were sent to him so he could measure them and do some "mapping" so he could offer decent cams to people.....BUT nothing good became of it.

He gets NO good recommendations at all from me and some of my other engine building friends.

OK guys I'm all third party to the issue with Dean so can't really comment. As you say thought Dave these guys have to deal with dreamers regularly. That said, Graham is a "known" person and it seems when Dean realised that he wasn't particularly interested in his business(afraid of being caught out?). He would sell him billets but wouldn't specify material or heat treat.

Graham has an old guy working on grinds right now but hes semi retired. We have worked with him on and off for 40 years and are confident that the cams will be spot on. Whether Graham's profiles work or not is another matter, as is the suitability of the stock material for another heat treat. Many cast irons can be nitrided after induction hardening(thats probably what the factory used) but it depends on a number of factors as to how the base material has been restructured by the original heat treat, and its depth.

Anyhow regrinds should give an idea as to HP, throttle response etc., and any valve gear or geometry issues that might arise. After that we may have to use Deans billets, but there is a big American caster that may be able to supply cast iron cores.

What base circle dia have you gone down to without running into geometry or excessive valve guide/stem wear/seizure issues?

Unfortunately since the passing of George Wade we have very few people left in this country with good knowledge of cams. George designed a lot of machines etc himself and apart from a couple of people who are no longer at Wades no one would have a clue how to use it. Probably 30 yrs ago he spent $40,000 building a measuring kit. Imported 2 Leitz lenses from Germany, had the software written, the works. It could measure lobes and masters every hundredth of a deg to about 6 dec places if my memory is correct. Even the Repco grinder is George's work. He designed that while working for them.

Cheers,
Alan

Considering the number of cars in the US using the Cyclone engine design, is there any chance of getting something 'off-the-shelf' from stateside?

G'Day Guys. Waiting for Jason to share his dealings with the another cam grinding company he's dealt with (apology in advance Jas but the cam issue is drastic). It might help people in assessing their options. Eg buy Tighe billets and have them ground by another company that has a more suitable profile for the application. My worry is the Tighe billets don't have enough material on the nose for the lift required.

Cheers Dave

G'Day Guys. Waiting for Jason to share his dealings with the another cam grinding company he's dealt with (apology in advance Jas but the cam issue is drastic). It might help people in assessing their options. Eg buy Tighe billets and have them ground by another company that has a more suitable profile for the application. My worry is the Tighe billets don't have enough material on the nose for the lift required.

Cheers Dave

Dave my old employer who i worked for after MMAL, is keen to make up "billets" for us. His business is a CNC machining place here in SA, all he requires is either a good blank sample or a drawing (He also does CAD work but will charge for that service), the best bit is if we get our own billets made then we can request exactly how much material we want left on the lobes for grinding :happy:

Ive been looking into having the above done for quite awhile now (hence why my old employer and i have spoken about cam billets on numerous occasions) but have been hesitant as i didnt wanna do a heap of setup work just to get a pair of blanks for just myself.

:D Never fear; I'm up for a set. What d'you xpect them to be worth - ballpark?


Dave my old employer who i worked for after MMAL, is keen to make up "billets" for us. His business is a CNC machining place here in SA, all he requires is either a good blank sample or a drawing (He also does CAD work but will charge for that service), the best bit is if we get our own billets made then we can request exactly how much material we want left on the lobes for grinding :happy:

Ive been looking into having the above done for quite awhile now (hence why my old employer and i have spoken about cam billets on numerous occasions) but have been hesitant as i didnt wanna do a heap of setup work just to get a pair of blanks for just myself.

EN40 or chilled cast iron with 1%Ni??
Gerry

:D Never fear; I'm up for a set. What d'you xpect them to be worth - ballpark?

Dont really know Ian, all depends on what material we use and then doing the drawing to achieve the blanks that we want and of course the setup costs for the CNC machining etc. The heat treating and cam journal grinding i can get done at a really good price.

Maybe i will get on to it once i get some spare time away from all my work and other commitments (current project is making Direct injection fuel pump "kit upgrades" for a place in sydney).

Maybe Dave TJ might like to work with me on getting some billets done??

Good to see this thread still alive in memory of magna00.......Phfftt:dancin:

I have a set of the prototype cams (from prototype engine number 2) sitting home, they have more duration (around the 260? total duration) and approx .4mm more (so 1.5mm more lift than stock TJ cams) lift than the official ralliart sticks. As for exact specs well im not sure, im sure Dave TJ or Rod would know more about them and no they arnt for sale.

Sorry Jason I missed this post. Were the cams in prototype engine number 2 on stock 32mm base circle and notched cam tunnel? If the tunnel was notched did you find any problems with journal lubrication/wear?

And Dave are your Tighe cams on 32mm base? or are you using lash caps or have you milled the rocker shaft seats?

I have passed the message to Graham that alternative billets may be available and he is quite keen on that. He has spoken to a few grinders using Tighe billets(not Magnas, for other engines) and they are having quality issues with some OK and others unusable. If the machining is inconsistent then how reliable is the heat treat?

Cheers,
Alan

If the machining is inconsistent then how reliable is the heat treat?
Bingo.

Alan our Tighe cams have standard base circle. MMAL tried a few cams so I'm not sure about Jasons cams unless he want's to tell me what is hand ingraved on the back of the cam.
Standard Ralliart gross intake valve lift is listed as 9.81mm by the data I have.

Cheers Dave.

OK thanks Dave. So your Tighe cams have relatively small lift then, about like the Ralliarts? The 32mm base limits the lobe to about 9.9mm max lift.

Graham measured his Ralliarts and 380s at about 0.388" +/- so that tallies with your figure of 9.81mm.

Cheers,
Alan

Alan our Tighe cams have standard base circle. MMAL tried a few cams so I'm not sure about Jasons cams unless he want's to tell me what is hand ingraved on the back of the cam.
Standard Ralliart gross intake valve lift is listed as 9.81mm by the data I have.

Cheers Dave.

Front cam has PR#2 and 112/9.91 roughly engraved on it, Rear cam has PR#2 and 108/9.94 roughly engraved on it

Also all the cams ive had made use the stock base circle as well. The ones i had ground from new "factory" cast billets were a very very tight and jiggly squeeze to get down the cam tunnels.

Thanks Jason for that.
Alan, the Ralliart cams have 9.83mm +/- intake lift (correction checked notes) and at that figure the valve spring is 1.5mm from coilbind. as you are aware the same cam only yeilded 9.68mm of intake lift in the 3.8 head. The Tighes only have 9.5mm of intake lift. I agree they need a heap more lift.

OK thank for looking at those cams Jason and also Dave. This is all useful info. Keeps my old grey matter from going to sludge too!

So Jason it would seem your Proto #2 cams were ground rear on 108 deg separation/9.94mm valve lift and the front on 112 deg/9.91mm lift, so that is about the max lobe height that would fit through the tunnel, and the springs would have been maxed out too.

Grinding on a smaller base circle should not be an issue if you are sensible and grind accurately free of chatter.(Graham's Ralliart cams were very bad for grind chatter, even the journals have chatter marks, but the 380 cams looked OK). The main issue is rocker geometry and valve stem/guide side loading. Either milling the rocker shaft seats to lower the rockers or lash caps to lengthen the valve stems, or a combo of both should not upset things, and there might be a nice increase in rocker ratio too.

The valve springs Graham had wound will handle race engine lifts, up around 15-16mm I think he said, so will easily run with the sub-11mm lift of his road cam. The springs are lower seat and open pressure than Mitsubishi springs but with bee-hive wind and ovate section wire have excellent harmonics and are less than half the weight. I think he is a bit concerned that he might get roller skidding if the spring pressures are too light, so he might have to shim these if there is an issue. Running good synthetic oils makes roller skid more of an issue too.

Cheers,
Alan

hi Alan, are you and Graham making any progress with your 3.8 'studies'?

hi Alan, are you and Graham making any progress with your 3.8 'studies'?

Zero things are on the move..........slowly.

Just a couple of days ago I got a message from Graham and he has the first master cam done. Its the lobes for the front bank. Thats the cam everyone messes up so he wanted to do it first. This is probably another reason for issues with grinding Magna cams. Apparently the norm has been for grinders to use just a pair of masters, often ripoffs from various EVO cams. That was OK for the rear bank, if you forget the lack of lift. But then for the front bank they merely turned the master over to reverse the lobe asymmetry ignoring that this put the beginning of the opening ramp on the closing side of the lobe and the end of the closing ramp on the opening side. Not good for lifter clatter, seat life or high rpm stability.

There is a jpg attached that he sent of the front bank master and the special valve springs he had wound with a stock spring for comparison.

He has done a head too and reckons he should have it on the flow bench soon. He has to make up the bits to open the valves and then its all go apparently. He also did a 3.5 head and will measure it and a Ralliart too while hes about it. As soon as he gets the numbers he'll send them to me and I'll get them posted.

Cheers,
Alan

OK Alan, thats great news with a start being made on your cams.....in regards to the rear bank mistake some grinders make,bloody hell! you'd think they'd be awake to that if they're in the 'game'. Thats something to check for if in doubt!...So the valve spings are the bee-hive ovate wind ones you were talking about..thanks for the pic's, they sound,look the part!....Looking forward to the flow bench figures... good luck, Al.

Alan, Graham,
The work that you are doing is finally going to get some decent NA performance bits for us.
I am just starting on the engine journey on my AWD.

Really, because the Magna is quite heavy, especially the AWD's, targetted modifications that have the most effect in the normal driving rev range will substantially improve how the car drives.

It is all very well to come up with a set of modifications that produce a track screamer but will be useless on the road.

I would like you opinion on a progressive modification programme :-
My ideas, in order are :-
1) Flow the throttle body

2) Simple cold air intake - AWD's are *rap on a hot day!

3) Advance the cams and get them to open the same on both banks, thanks for the details on how to do this. BTW I have an idea for a very cheap electronic protractor to speed up this fiddly timing job.

4) Streetfighter inlet manifold.

4) New extractor system - looks as if for bang for the buck on an AWD then it is the HM Headers system.

5) High flow cat, already have the sports rear muffler as the car is a Sports.

6) ECU retune - maybe soon we can have a ECU weekend in Sydney with Steve Knight!

Then it starts getting more labour / cost intensive -
7) Clean up the cylinder heads, deshroud the inlet valves in the combustion chambers, smooth out the ports etc.
8) Cams, valve springs etc. Time them in correctly as well!!
9) High compression pistons.
Obviously an ECU tune/s are required with these.

Any comments.
Cheers Gerry

QUOTE=spud100;1043983]Alan, Graham,
The work that you are doing is finally going to get some decent NA performance bits for us.
I am just starting on the engine journey on my AWD.

Really, because the Magna is quite heavy, especially the AWD's, targetted modifications that have the most effect in the normal driving rev range will substantially improve how the car drives.

It is all very well to come up with a set of modifications that produce a track screamer but will be useless on the road.

I would like you opinion on a progressive modification programme :-
My ideas, in order are :-
1) Flow the throttle body

2) Simple cold air intake - AWD's are *rap on a hot day!

3) Advance the cams and get them to open the same on both banks, thanks for the details on how to do this. BTW I have an idea for a very cheap electronic protractor to speed up this fiddly timing job.

4) Streetfighter inlet manifold.

4) New extractor system - looks as if for bang for the buck on an AWD then it is the HM Headers system.

5) High flow cat, already have the sports rear muffler as the car is a Sports.

6) ECU retune - maybe soon we can have a ECU weekend in Sydney with Steve Knight!

Then it starts getting more labour / cost intensive -
7) Clean up the cylinder heads, deshroud the inlet valves in the combustion chambers, smooth out the ports etc.
8) Cams, valve springs etc. Time them in correctly as well!!
9) High compression pistons.
Obviously an ECU tune/s are required with these.

Any comments.
Cheers Gerry[/QUOTE]

Gerry the kit that Graham is working on is aimed squarely at what you have in mind. This is costing Graham a packet, both in his time and money so he has to do research that will suit the majority(he reckons he could have fitted a blower for what the 4 master cams and a pair of experimental sticks are costing him). That means it going to suit average guys who want more go with minimal downside from their Magna/Pajero/380, much like what you would expect from an authorised manufacturer performance upgrade.

Regarding your modification list my comments on each point are(note Graham might disagree on some of this):

1) If you can get the 2 lips out of the throttle body yourself without cost then OK. Otherwise it won't do much in engines up to 200kw. Above that there may be a gain.

2) Intake is definitely restricted, this was to reduce induction noise, and needs another inlet snorkel to be added. Graham put in a low 60mm flex pipe and I have a similar arrangement. Now there is no restriction but when heads and cams are added later this may require a rethink.

3) Cams adv is essential for performance and economy. Interested in your electronic protractor.

4) Don't know about the Streetfighter, I don't see a problem with the stock item, except that plenum may be a bit small. Graham has done heads with a lot of different configurations and is currently flowing them on the bench. Several use the stock manifold with the runner bore reduced considerably to pick up gas velocity and reduce runner volume. The manifold runners look enormous to me so can't see how Ian's twin runners can improve things unless a butterfly was used to block the second port at lower rpm. I know Graham did take Ian's car for a run and by the backside dyno it seemed to feel good, so perhaps the twin ports help by creating turbulence near the injector that improve mixture quality, and you get a better fuel burn. Equally more spark adv might do the same for very little $.

4x) Yes headers are the easy fix for the very restrictive rear bank join. Graham and I both have HM. We have dealt with HM for a long time so have confidence their bits fit properly and have been well engineered. Welding is rubbish though, not like the pretty welding coming out of Japan, but then its only a fraction the price too. In low HP engines the actual design isn't very important except to say you want short primary pipes so that the secondaries can be as long as can be easily accommodated. It is the long secondaries that help lift the bottom end and mid-range. If we can do it without introducing unwanted harmonics into the pipes we would like to cut the HMs and add length to the secondaries so that they don't join until back near the Lambda sensor.

5) The VR-X/VR/Sports rear muffler is an essential. Not sure about so called high flow CATs. If its got metal guts thats a good thing, but many are still very disruptive to ex flow due to incorrect pipe entry and exit angles.

6) There will be big gains here.

7) Will post the results of Graham's flow testing as soon as he is through. The inlets need deshrouding for sure, but I don't think for the ex. When I visited Graham a couple of months ago he had done a 6G74 chamber and didn't touch the chamber near the ex valves. We both agreed that the ex most likely flows too well compared to the inlet and opening up the chamber will just slow the burn and lower the comp ratio, so the engine may end up more sluggish with stock ECU. The twinned inlet ports are just a touch small for big HP but OK for a street engine. The main issue is the single port area is way too big. Graham has filled the port to help velocity. This will get a better fuel mix too as his manifold runner and inlet port go smaller just before the injector. The higher air speed lowers manifold pressure, so the fuel vaporises easier, and the extra speed helps to rip/shear the fuel droplets apart. Will be interesting to see the flow results. I don't think the small ports will hurt flow, may even help it in fact, but at any rate they will liven up the engine through most of the rev range.

8) Definitely needs more cam, hopefully Graham's effort bears fruit and gives better bottom end HP than Ralliart with a lot more up top. After he has cams ground then he will run reliability tests, so cams are some time away yet.

9) High compression is very over-rated. Good for fuel economy but can be very restrictive when it comes to getting mild road cams working over a broad range as you can't use so much cam adv, and retarding the ign to avoid high load/high rpm detonation can take away any upper end power gains, or maybe even cost power due to poor/late burn. Stock 9:1 isn't ideal but unless the engine needed a rebuild with new pistons I wouldn't recommend shelling out on high comp pistons. The DOHC Pajero pistons are misquoted as being 10:1. According to Graham they are closer to 9.7-9.8:1 with the SOHC heads, and thats not going to give much HP above stock 9:1.

Cheers,
Alan

Alan,
Thank you for your insightful comments.
I was not only thinking of myself when I put the original post up.

You are confirming what I beleive is the best way to turn the 6G74 engine into a really nice performing one without having a WAF problem with a turbo or S/C.

I put the items in an order that I felt covered increasing cost/ difficulty as well as bang for the buck.

I came through the ranks at Ford in the UK.
First car was originally a 105E Anglia, it soon had a 1600GT engine in it with carb, head, cam and exhaust work + Lotus Cortina brakes, twin servos, suspension work and bigger wheels & tyres - 185/70/13's!!
I was in the Trade school at the time, another pair of weapons were a Coventry Climax Anglia, and another with a 3.8 Jag engine in it.
At that time the play car the school had was a road going GT 40!!

Love the AWD as a package.
Big pity that MMAL did not fully develop it, they really had cold feet regarding a manual transmission and also did not go ahead and give it the power that the chassis can handle.
Hate the throttle response at Sydney traffic revs.
The worst part is to get it going you have to plant it and then suffer poor fuel consumption.

I am watching your developments with Graham with much interest.

Electronic Protractor.
I bought an electronic angle finder from Carba-Tec last year.
Checked it against our $2,000 instrument at work. It's pretty good, both accurate and repeatable to around ± 0.2 degree.

Has a pair of magnets in the base of the case to adhere to metal surfaces.
I am looking at a small angle bracket that can be stuck to the crank pulley with another powerful button magnet.

Just find TDC. Hit the zero button and then it should be fairly quick to find the cam opening angles.
I reckon if one is pulled apart it would be possible to separate the display from the sensor, then it could be used in-car with the display brought up to the top of the engine.

Here is a link to the beastie. Not expensive - $79.
http://www.carbatec.com.au/machinery-for-wood-and-metal-working/machinery-for-wood-and-metal-working-accessories/jigs-guides/magnetic-angle-finder.

There is also a better one as well with 2 sets of magnets for $99.
http://www.carbatec.com.au/machinery-and-accessories/machinery-accessories/jigs-guides/heavy-duty-digital-angle-finder

Cheers,
Gerry

9) High compression is very over-rated. Good for fuel economy but can be very restrictive when it comes to getting mild road cams working over a broad range as you can't use so much cam adv, and retarding the ign to avoid high load/high rpm detonation can take away any upper end power gains, or maybe even cost power due to poor/late burn. Stock 9:1 isn't ideal but unless the engine needed a rebuild with new pistons I wouldn't recommend shelling out on high comp pistons. The DOHC Pajero pistons are misquoted as being 10:1. According to Graham they are closer to 9.7-9.8:1 with the SOHC heads, and thats not going to give much HP above stock 9:1.

Cheers,
Alan


Alan,

2 of the magna 3.5L engines that i have built that have used the DOHC pajero pistons have both worked out to 10.2:1 comp (when used with the SOHC heads) so i dont know where Graham has got the 9.7-9.8:1 comp from..... the Pajero piston has a smaller bowl and the CC is slightly smaller (by a couple of cc's) in the SOHC head. Even 10.2:1 comp wasnt enough for me hence why my "big" build runs around the 11.2-11.5 compression range.

Anyway intersting to see that he thinks otherwise but Graham has his ways and i have mine :)

jason, if your donkey engine can run allmost 190Kw ATW, what is your big engine putting out?

jason, if your donkey engine can run allmost 190Kw ATW, what is your big engine putting out?

The donkey will make around 200Kw@wheels once it has the larger injectors fitted and is tuned to suit (currently gets very lean over 4700rpm). The big engine when it was last in the car ran in the mid 230's and that was with a "dodgy" front cam (incorrect profile on the 3 exhaust lobes) from Tighe. The aim for that engine was/is 250 once sorted and then it will have a small shot of nitrous added for sh*ts and giggles

The donkey will make around 200Kw@wheels once it has the larger injectors fitted and is tuned to suit (currently gets very lean over 4700rpm). The big engine when it was last in the car ran in the mid 230's and that was with a "dodgy" front cam (incorrect profile on the 3 exhaust lobes) from Tighe. The aim for that engine was/is 250 once sorted and then it will have a small shot of nitrous added for sh*ts and giggles

and still N/A that is just insane dude, love it :thumbsup:
you gota write up a thread, in members rides, dedicated to this engine alone

Alan,

2 of the magna 3.5L engines that i have built that have used the DOHC pajero pistons have both worked out to 10.2:1 comp (when used with the SOHC heads) so i dont know where Graham has got the 9.7-9.8:1 comp from..... the Pajero piston has a smaller bowl and the CC is slightly smaller (by a couple of cc's) in the SOHC head. Even 10.2:1 comp wasnt enough for me hence why my "big" build runs around the 11.2-11.5 compression range.

Anyway intersting to see that he thinks otherwise but Graham has his ways and i have mine :)

Jason, I sent Graham your info and he replied with unmilled heads, unmodified stock valves and uncut valve seats he measured 9.7-9.8:1, that his stock pistons have a 24.6 cc bowls and his Pajero DOHC pistons have 17.5 cc bowls. He said both pistons have the same comp height. Maybe your heads or block had been milled? Or the valves were non-stock or seats/inserts were set higher in the chamber?

Yes with crazy cams you need tight compression but Graham is working at a good road engine to operate on 95RON fuel that will suit the needs of most. Such an engine will be a lot nicer and perform better overall with a moderate comp ratio.

V8 Supercar engines are a good local example of what can be achieved with only 10:1 comp. Before E85 we were approaching 660-670HP at 7200-7300rpm from 5 ltrs. The NASCAR Busch engines are only 9:1 and make 680-700HP from 5.8 ltrs strangled by a single tiny 390cfm Holley carb.





Alan,
Thank you for your insightful comments.
I was not only thinking of myself when I put the original post up.

You are confirming what I beleive is the best way to turn the 6G74 engine into a really nice performing one without having a WAF problem with a turbo or S/C.

I put the items in an order that I felt covered increasing cost/ difficulty as well as bang for the buck.

I came through the ranks at Ford in the UK.
First car was originally a 105E Anglia, it soon had a 1600GT engine in it with carb, head, cam and exhaust work + Lotus Cortina brakes, twin servos, suspension work and bigger wheels & tyres - 185/70/13's!!
I was in the Trade school at the time, another pair of weapons were a Coventry Climax Anglia, and another with a 3.8 Jag engine in it.
At that time the play car the school had was a road going GT 40!!

Love the AWD as a package.
Big pity that MMAL did not fully develop it, they really had cold feet regarding a manual transmission and also did not go ahead and give it the power that the chassis can handle.
Hate the throttle response at Sydney traffic revs.
The worst part is to get it going you have to plant it and then suffer poor fuel consumption.

I am watching your developments with Graham with much interest.

Electronic Protractor.
I bought an electronic angle finder from Carba-Tec last year.
Checked it against our $2,000 instrument at work. It's pretty good, both accurate and repeatable to around ± 0.2 degree.

Has a pair of magnets in the base of the case to adhere to metal surfaces.
I am looking at a small angle bracket that can be stuck to the crank pulley with another powerful button magnet.

Just find TDC. Hit the zero button and then it should be fairly quick to find the cam opening angles.
I reckon if one is pulled apart it would be possible to separate the display from the sensor, then it could be used in-car with the display brought up to the top of the engine.

Here is a link to the beastie. Not expensive - $79.
http://www.carbatec.com.au/machinery-for-wood-and-metal-working/machinery-for-wood-and-metal-working-accessories/jigs-guides/magnetic-angle-finder.

There is also a better one as well with 2 sets of magnets for $99.
http://www.carbatec.com.au/machinery-and-accessories/machinery-accessories/jigs-guides/heavy-duty-digital-angle-finder

Cheers,
Gerry



OK Gerry I've passed this on to Graham as well. Interestingly his first love was a 105E Anglia too (for you young guys thats the Harry Potter movies car with the reverse slant rear glass, and you'll also see it in some British cop shows). Like you he didn't have an Anglia for long either. Finished up being Anglia body with a 170 HP Lotus Twin Cam engine, and regularly run to 230 kph(no speed limits in Aust then. Police couldn't have caught him anyhow in Minis and GTR Toranas). For a reserved guy he regularly surprised us with his exploits of running down 350 Monaros and GT HO Falcons, and then rubbed salt into the wound by waiting for them further along the road and doing them over again! Hes a gentleman now though, so I probably shouldn't be telling tales like this.

Cheers,
Alan

G'day Alan. Here's the Factory nomiated volumes.

Std 3.5 chamber=43.1
Std 3.5 piston volume=22.6
Std 3.5 Ralliart chamber=44.1
Std 3.5 Ralliart piston volume==18.1
Std cc for crown to top ring clearance =1.1
Std 3.5 gasket volume=3.5
Std 3.5 comp ratio=9.0:1
Std Ralliart comp ratio=9.4

These are just the factory figures I have, the numbers do vary from engine to engine. Hope this is of help guys.

Cheers Dave

Hi ya Alan, I'm curious to know, in which direction you guy's were heading with engine management?

Hi ya Alan, I'm curious to know, in which direction you guy's were heading with engine management?

Still undecided at this time. First up want to see how the stock tune goes for HP, driveability and economy to get a baseline set of numbers. Graham wants to keep it as simple as possible so anyone can fit the cams and heads and not have a lot of hassles getting a good result. The heads will be OK, but the cams may be an issue. Undoubtedly it will be way too rich for best HP and economy.

He also has a spark sensor kit to change base ign timing and that may help, and it will reduce fuel consumption in closed loop if more advance is what the engine requires.

Most likely the final solution will be to flash the ECU. He will do that anyway I expect, even if the engine works OK without ECU map changes, to see how much HP and economy a reflash is worth.

Cheers,
Alan

Ok Alan, thanks for that,i expected you fella's would be interested in a flash at some stage.....the sensor kit sounds interesting.
Any joy with the cams yet? bit soon i suppose.....good luck!,watching with interest!

Alan,
How is it going??

Gerry

Alan,
How is it going??

Gerry


Latest from Graham is that he has heads ready for the flow bench for a couple of last minute tweaks that he hopes will do some good. He got back to Aust a couple of weeks back with the finished cams and he has verified the valves clear the pistons of the 3.5 6G74 without piston cutouts but is yet to check on a 380 6G75. He reckons another couple of weeks and it should be go.

Cheers,
Alan

Graham just sent me pics of the stock 380 piston. Flat top with small intruder, full slipper design and interestingly a steel top ring insert.

Cheers,
Alan

Could it really be that hard to deck the sodding piston at the foundary instead of leaving all those potential hotspots?! It's not like the mexican on the assembly line is going to accidentially slot the piston into a 6G72 mivec by accident is it?

Was pretty light from memory too.

Could it really be that hard to deck the sodding piston at the foundary instead of leaving all those potential hotspots?! It's not like the mexican on the assembly line is going to accidentially slot the piston into a 6G72 mivec by accident is it?

Was pretty light from memory too.

Sorry forgot to add the weights/specs.

Piston was 357gm and pin 112gm.

top and 2nd ring both 1.2mm, oil rings 2mm

top ring only 4mm down


Cheers,
Alan

The top ring groove on the piston is anodized to protect the low grade alloy there made out of.

Cheers Dave

Great :doubt:

Tell me is wasn't cheaper to reduce the silicone content and sure up the brittility? Who *really* cares if there's little engine noise on start up? More deadening on the firewall ftw.

The top ring groove on the piston is anodized to protect the low grade alloy there made out of.

Cheers Dave

Did they put steel inserts in some and anodise others depending on piston supplier?


Great :doubt:

Tell me is wasn't cheaper to reduce the silicone content and sure up the brittility? Who *really* cares if there's little engine noise on start up? More deadening on the firewall ftw.

The problem with very high silicone content is that the pistons can break almost like glass when subjected to detonation. Lowering the silicone % makes the piston more "plastic" thats why the old WWII Rolls Royce alloy mix, or a variant of that brew, is generally used in race engines. It needs more clearance but you can drop a valve and the piston will get holed but not crack, so the engine can hopefully run to the race finish, down 1 cylinder. This softer alloy has a down side in road engines. Apart from needing more clearance there is more ring land wear, so needs to be anodised or steel inserted.

Cheers,
Alan

The slugs in our old astron2 sigma 2L must've been made of blue-tac; it'd knock and rattle its tits off in any gear at any load - compounded by the emergence of those sodding 50k zones!

Will check that out Alan J, the anodizing colour does vary with manufacturers, yep it's for top ring groove longevity.

Cheers Dave

Dunno if this was mentioned but some good info from 3si.org
"Ok Guys, here is the latest with my attempts to achieve larger displacement using a 74 block and 75 crank. I purchased a 75 short-block to compare cranks, rods and pistons to my 74. As it turns out, I was easily able to remove the 75 crank (steel) and install it into the 74 block with absolutely NO issues. I easily installed the 74 girdle with no rotating interference at all. Then I compared the rods and pistons. Get this, the 75 uses the same rod as the 74..Yep, they are exactly the same length and are both stamped 74! The entire difference in stroke between the 74 and 75 is accounted for in the piston (placement of pin). The measurement between the pin and top of the 75 piston is a little over 2mm less then the 74. I then took a 75 rod and mounted a 74 piston and installed it into the 74/75 block/crank. Sure enough, the piston protruded ~2mm over the deck. As I rotated the assembly, I noticed that there really isn't much room between the crank counter weight and piston bottom @ BDC. I believe this means that a shorter rod is probably out of the question unless you cut the counterweights. I guess the solution for ~3.75L is 74 block (.020 over), custom pistons with pin ~2mm closer to the top, and a 74 rod. I’ll take some pics and post the info latter.."

http://www.3si.org/forum/attachments/f1/69382d1200866523-6g74-75-info-74-75-1.jpg

not sure if the picture works

Graham has emailed some pictures of the upper manifold differences.

At first glance the 380 looks better as the runner has a nice taper from the plenum that should flow more. However the 3.5 has a much shallower bend so flow probably wouldn't be much different, and may be better with the 3.5. An acute bend like the 380 really hurts flow and creates turbulence.

http://i837.photobucket.com/albums/zz294/AlanJoy/bend.jpg

http://i837.photobucket.com/albums/zz294/AlanJoy/top.jpg

Graham would like to try a shorter runner and should be fairly easy with the 3.5 to cut out about 80mm. The EGR passage would have to be cut/ground off so that the plenum cleared the spark plug caps and the plenum modified to move the T/B mount back.

Cheers,
Alan

Alan, do you guy's have a preference between the two, for the shape of the other sect. of the manifold that the t/b bolts to.
Cheers mate.

Alan, do you guy's have a preference between the two, for the shape of the other sect. of the manifold that the t/b bolts to.
Cheers mate.

Graham sent a sketch of what he has in mind if he gives the shortened 3.5 a try. Basically to keep the T/B close to the stock location and to clear the distributor he will weld a section to the rear of the plenum. It will almost be the 380 style inlet neck but swung back through 60-70 deg if you can visualise that.

The other possibility he mentioned was to split the 3.5 plenum and space it rearwards, wedge shaped, wider near the T/B end. That would add plenum volume but take away from the stealth appearance that Graham favours.

Cheers,
Alan

Graham sent a sketch of what he has in mind if he gives the shortened 3.5 a try. Basically to keep the T/B close to the stock location and to clear the distributor he will weld a section to the rear of the plenum. It will almost be the 380 style inlet neck but swung back through 60-70 deg if you can visualise that.

The other possibility he mentioned was to split the 3.5 plenum and space it rearwards, wedge shaped, wider near the T/B end. That would add plenum volume but take away from the stealth appearance that Graham favours.

Cheers,
Alan

Ok...both sound interesting and i can relate to Grahams preference for stealth mods.
Hopefully he tries both theories, i'll look forward to this as will many others. Fingers crossed!
Thanks for your usual generosity with info.

Graham sent a sketch of what he has in mind if he gives the shortened 3.5 a try. Basically to keep the T/B close to the stock location and to clear the distributor he will weld a section to the rear of the plenum. It will almost be the 380 style inlet neck but swung back through 60-70 deg if you can visualise that.


Sounds like a conversation G and I had. Looks like he cleaned up the plenum I gave him. Is he still wanting to 'neck down' the runners to conform to the lower manifold runner ports? I assume his favourite bog will be busy again. :)

Let him know I can weld it up for him when he's ready to reassemble.

Ian.

What I would like to see would be a custom inlet with individual throttle bodies and trumpets for each. Has this ever been done?

What I would like to see would be a custom inlet with individual throttle bodies and trumpets for each. Has this ever been done?

Apart from being a nightmare tuning/cabling wise, the 6G motors dont breathe enough to warrant having them.

Sounds like a conversation G and I had. Looks like he cleaned up the plenum I gave him. Is he still wanting to 'neck down' the runners to conform to the lower manifold runner ports? I assume his favourite bog will be busy again. :)

Let him know I can weld it up for him when he's ready to reassemble.

Ian.

Could be your manifold Ian. Graham sent me these today. He was thinking the 380 manifold was probably the way to go a week or two ago. But that has obviously changed since he sat both side by side.


What I would like to see would be a custom inlet with individual throttle bodies and trumpets for each. Has this ever been done?

The best compromise for a road car is like done on the Walkinshaw VL Gp A Commodores, which was a copy from the Rover Vitesse V8 a few years earlier. A airbox between the 'V' and trumpets crossing over in the airbox, with a T/B or twin T/B feeding in. You still get the benefit of progressive throttle opening to control wheelspin like a normal plenum setup, but you can tune the runner lengths to move the torque peak to what suits different cams, driving styles etc.

I'll see if I can find some pictures of the Rover and Holden setup. Its getting to be almost 30 years ago and some wouldn't know what I'm talking about without pictures to explain.

Individual throttles work very well but are expensive, a pain to tune and to map accurately at mild throttle openings, and around town not very nice unless they have electronic butterfly control (that is why superbikes are so 'snatchy' at low revs and a pest to ride in traffic). Plus on a wet road throttle modulation is quite difficult. The instant response that feels so good in the dry is a nightmare when its wet. Like driving on ice with 500hp in 1st or 2nd gear.


Apart from being a nightmare tuning/cabling wise, the 6G motors dont breathe enough to warrant having them.

Tuning and linkages are a problem as you say. However its not correct to say the 6G7x doesn't breathe well enough to warrant them. As an early modification it would be all show, but as you got more serious it would be another way to unlock perhaps 20-40 kw in the higher rev range (and lose kw at lower rpm too). With a stock type manifold an engine making 250kw could pick up that sort of power between say 5500-7500rpm. That might seem unrealistic but with the right bits to keep the engine holding together the flow potential of the 380 heads Graham did would breathe enough for 310-330kw. The biggest problem would probably be getting the rockers to live with a sporty duration cam lifting the inlet valves 13mm+.

Cheers,
Alan

Could be your manifold Ian. Graham sent me these today. He was thinking the 380 manifold was probably the way to go a week or two ago. But that has obviously changed since he sat both side by side.



The best compromise for a road car is like done on the Walkinshaw VL Gp A Commodores, which was a copy from the Rover Vitesse V8 a few years earlier. A airbox between the 'V' and trumpets crossing over in the airbox, with a T/B or twin T/B feeding in. You still get the benefit of progressive throttle opening to control wheelspin like a normal plenum setup, but you can tune the runner lengths to move the torque peak to what suits different cams, driving styles etc.

I'll see if I can find some pictures of the Rover and Holden setup. Its getting to be almost 30 years ago and some wouldn't know what I'm talking about without pictures to explain.

Individual throttles work very well but are expensive, a pain to tune and to map accurately at mild throttle openings, and around town not very nice unless they have electronic butterfly control (that is why superbikes are so 'snatchy' at low revs and a pest to ride in traffic). Plus on a wet road throttle modulation is quite difficult. The instant response that feels so good in the dry is a nightmare when its wet. Like driving on ice with 500hp in 1st or 2nd gear.



Tuning and linkages are a problem as you say. However its not correct to say the 6G7x doesn't breathe well enough to warrant them. As an early modification it would be all show, but as you got more serious it would be another way to unlock perhaps 20-40 kw in the higher rev range (and lose kw at lower rpm too). With a stock type manifold an engine making 250kw could pick up that sort of power between say 5500-7500rpm. That might seem unrealistic but with the right bits to keep the engine holding together the flow potential of the 380 heads Graham did would breathe enough for 310-330kw. The biggest problem would probably be getting the rockers to live with a sporty duration cam lifting the inlet valves 13mm+.

Cheers,
Alan

aye, my experience is with the little 1600 GM/Opel/Vauxhall 16v unit found in the sporty Barina GSi

http://media.photobucket.com/image/X16XE%20throttle%20bodies/grimmy1988/Photo-0082.jpghttp://www.sbdev.co.uk/SBD_West/pic3.gif

http://i233.photobucket.com/albums/ee168/grimmy1988/Photo-0082.jpg

Not too difficult getting the 1.6 pushing 140-150kW with a well setup unit like this and 90 lb/ft torque per litre. Some competition engines running the TB kits on the 1600 in Westfields and Caterhams can see up to 180kW from the 1.6, but with a 10,000RPM rev limiter

aye, my experience is with the little 1600 GM/Opel/Vauxhall 16v unit found in the sporty Barina GSi
Not too difficult getting the 1.6 pushing 140-150kW with a well setup unit like this and 90 lb/ft torque per litre. Some competition engines running the TB kits on the 1600 in Westfields and Caterhams can see up to 180kW from the 1.6, but with a 10,000RPM rev limiter

Yes great little engine those; even with stock cams retimed and individual throttles they make 120kw with ease.

I found pictures of the Rover setup. Still looking for the Walkinshaw Gp A Commodore shots.

http://i837.photobucket.com/albums/zz294/AlanJoy/airbox.jpg

http://i837.photobucket.com/albums/zz294/AlanJoy/trumpets.jpg

Cheers,
Alan

wow thats an interesting setup!!! I guess the ample room in the bay of a Rover V8 would be ideal for setting up that induction system.

Or a whipple blower...

I found pictures of the Rover setup. Still looking for the Walkinshaw Gp A Commodore shots.
Does this help?

http://img42.imageshack.us/img42/4553/img3018u.th.jpg (http://img42.imageshack.us/i/img3018u.jpg/)

My old man owned one since new up until a few years ago...

Like the airbox :)

A pair of smaller TBs off say a lancer etc would be useful - giving good response and not making the car a jumpy pig in traffic. Split the plenum into halves 1-3 and 4-6 to give similar air lines of flow thru the TBs mounted with openings to the firewall, have a dual pair of elbows heading back to the std airbox location. Throttle cables and linkages are simple enough to relocate and add/subtract to. A lot of TBs at wreckers will have the ball end of the cable still attached to the TB when they give it to you.

OR dual layer plenum 1,3,5 and 2,4,6 would give better flow chazas.

How hard is it to get hold of a 6G75? and if I just delivered my car to a mechanic and said 'swap' they should be able to figure it out alright yea? (I know thats very simplified and I wouldn't be able to do any of it myself)

when the VRX is paid off in a year was gunna take out 6k to do up the engine, but the list of parts I wrote up looks quite expensive compared to just putting a newer, bigger capacity engine in.

How hard is it to get hold of a 6G75? and if I just delivered my car to a mechanic and said 'swap' they should be able to figure it out alright yea? (I know thats very simplified and I wouldn't be able to do any of it myself)


You would have to find a mechanic/workshop that takes on engine swaps. This sort of thing freaks many out.

If you read through the previous posts and take note of whats required to do the swap the mechanic won't have to figure it out and that will find more mechanics willing to do the swap when they have good info on what to do, plus save you money as they won't waste time working things out.

Just by way of an update on the swap, Graham has just done the 3.8 into his AWD and asked me to pass on two more things to save time.

If you use an ordinary 3.5 sump on the AWD you have to angle grind a small nob of alloy off the sump rear rail to clear the transfer case. He will send a picture later.
The 3.8 also has a slightly different alloy bracket for the A/C tensioner pulley and cam belt idler pulley. There are two threaded bosses on the 3.8 bracket that get in the way of the 3.5 A/C compressor mount bracket. The bosses can be ground off but its better to use the 3.5 bracket. Graham only found this out when he had the 3.8 engine in and tried to get the A/C bracket to fit and it wouldn't go.


Cheers,
Alan

6k is a LOT of $ to throw at a natmo 6G7x. Are you doing the work yourself? I built my forged motor for about half that figure.

6k is a LOT of $ to throw at a natmo 6G7x. Are you doing the work yourself? I built my forged motor for about half that figure.

Howd you do that at 3k? Did that include porting of the heads, balancing and all machining? All you did was reassemble? What would your forged motor cost if it was assembled by a workshop?

Howd you do that at 3k? Did that include porting of the heads, balancing and all machining? All you did was reassemble? What would your forged motor cost if it was assembled by a workshop?

I was just throwing an approx figure out there. The motor was $400 (new short block), 2x heads $60ea, forged slugs $1870, ralliart springs, adjustable cam gears, ralliart cams, gasket kit, arp rod bolts etc. Balance $300? Can't remember. If it was a natmo build the pistons are 10:1 items from ACL at like $400 a set. Did the headwork myself, water galleries, block flushing etc. It's very easy for a natmo build to hit big $$$$ when a workshop is stinging you at least $55/hr. How fast would you work if you were getting paid $55 an hour until a task was completed ;)

Balance $300?

When you get the internals balanced, do you just give the workshop the crank, pistons and conrods, or do you have do give them the whole assembled block to balance?

Give them the entire bottom end bar crank bearings (i think). So rods, rod bolts, rod bearings, pistons, rings, pins and clips, crank. Did I forget anything? I've only gone thru this once and it was almost a year ago so go gentle with the flaming!