Well Ladies and Gents,
As of this coming Saturday i will be the proud owner of a set of DOHC cylinder heads for my 6g74. I have checked with the seller and the gaskets have zacharys disease to the magna ones so they will bolt straight on to the block. All i have to do now is actually go and pick them up and do the conversion. It will have to come soon because my clutch is slipping like buggery! lol.

More updates to come.

wont the throttle body be on the wrong side?

Sounds awesome though mate! Let us know how you go.

The 6G74 head is more attractive than the head in your avatar :bowrofl:

Will be interested to see how this goes.

so what your saying is that you can convert SOHC 24v to DOHC 24v?
What about SOHC 12v to DOHC 24v? thats what i need to know.....

Cause the 3.0 and 3.5 blocks are the same arn't they? Shoot me if need be.

so what your saying is that you can convert SOHC 24v to DOHC 24v?
What about SOHC 12v to DOHC 24v? thats what i need to know.....

Cause the 3.0 and 3.5 blocks are the same arn't they? Shoot me if need be.

BANG.


Wrong, they don't match up for some reason or another, I've read before.

2nd gen 6G72 is different to 3rd gen 6G72, so i'd imagine that it wouldnt work. But maybe the heads off of tuff tr's DOHC would?

2nd gen 6G72 is different to 3rd gen 6G72, so i'd imagine that it wouldnt work. But maybe the heads off of tuff tr's DOHC would?
Tuff has a 6G74 DOHC from a Debonair...

KB, Jet-BLK, Dimi and whoever else have the 6G72 DOHC from the Diamante/3000GT/GTO/Stealth.

Don't know what everyone is talking about here with the inclusion of second gens into the thread, Screamin TE's heads are for the third gen 6G74... These heads are off what, a Pajero of the same variant? I wonder if these will fit...

The 6G74 head is more attractive than the head in your avatar :bowrofl:

LOL badly lol

Tuff has a 6G74 DOHC from a Debonair...

KB, Jet-BLK, Dimi and whoever else have the 6G72 DOHC from the Diamante/3000GT/GTO/Stealth.

Don't know what everyone is talking about here with the inclusion of second gens into the thread, Screamin TE's heads are for the third gen 6G74... These heads are off what, a Pajero of the same variant? I wonder if these will fit...


They are off of a 94 GLS Pajero, not sure what 'N' series it is. The bloke i am getting them oof sent me a pic of the cylinder head gasket and it is identical to the one i have here for the 6G72/74 out of the 3RD gen Magna.

94 NH Pajero has a 2nd gen 3.0, You need 96 onwards

94 NH Pajero has a 2nd gen 3.0, You need 96 onwards

hope you are wrong or the poor OP will be up **** creek...

Garhhh... had this thread come up sooner i wouldn't have sold my TF in favour for a TL, would have opted for the conversion... then again i could do this to the TL... hmm...

theres no NH in '94 (well according to redbook),theyre all NJ, and the only 3.5L is the exceed, which was DOHC... maybe its that one?
http://www.redbookasiapacific.com/au/vehicle/specs.php?id=89077

same engine on some '95, '96 and '97 models, but ends before the NL model

They are off of a 94 GLS Pajero, not sure what 'N' series it is. The bloke i am getting them oof sent me a pic of the cylinder head gasket and it is identical to the one i have here for the 6G72/74 out of the 3RD gen Magna.


My Bad, they are off a 96, and it didnt state it was a GLS, dont know where that came from. Oh well....... They will fit none the less.

The 94 pajero we have is a TR/TS V6 and the 3.5 DOHC pajero is whats going into tuff tr magna. sure its 95/96 onwards with the standard 3.5 143kw engine.

My Bad, they are off a 96, and it didnt state it was a GLS, dont know where that came from. Oh well....... They will fit none the less.

then they will fit:D

so what sort of changes can you expect if you go DOHC. also what other modifications are necessary?

SOHC 3.5lt motors made more power than the DOHC pajero's.

Pajero's being 4x4 need more of everything down low in the rev range which will hurt the power outout up high due to the cams. 140kw in the 3.5 pajero's, less in the 3.0's.

I was hoping they were imported ones.

Just to put it in postective, 3.0 MIVECS are $2000 or $2500 for a front cut from a lot of jap wreckers. They have what 194kw?

Just to put it in postective, 3.0 MIVECS are $2000 or $2500 for a front cut from a lot of jap wreckers. They have what 194kw?


now you say... i didn't know how or where to get the mivec engine when my hands got itchy with my TF i ended up selling it... why do everything comes up after i sell her...

well i guess the next mod the OP can do is get cams for his car

now you say... i didn't know how or where to get the mivec engine when my hands got itchy with my TF i ended up selling it... why do everything comes up after i sell her...

well i guess the next mod the OP can do is get cams for his car

Or you can regrind your cars, use these valve springs that I'm going to use for the ability for wicked lift and there's no point in cams unless head work is done at the same time.

SOHC 3.5lt motors made more power than the DOHC pajero's.

Pajero's being 4x4 need more of everything down low in the rev range which will hurt the power outout up high due to the cams. 140kw in the 3.5 pajero's, less in the 3.0's.

I was hoping they were imported ones.

Just to put it in postective, 3.0 MIVECS are $2000 or $2500 for a front cut from a lot of jap wreckers. They have what 194kw?


Wasnt goin to just put them on. Was thinkin port the inlets, match port and polish the exhaust, obviously the ignition timing will be different for each.
May even fit the magna valves if they are bigger.

Oh ok, cool

Was just going to note that the combustion chambers would be different so the compression ratio after fitting would be different, if the chambers are a lower cc the compression would be higher and if a higher cc vice versa.

Looks good man, glad you know what they are for :)

Or you can regrind your cars, use these valve springs that I'm going to use for the ability for wicked lift and there's no point in cams unless head work is done at the same time.


You cant regrind the cams in a 3rd gen because they have hydraulic lifters. All that will happen is the lifter will expand to compensate for the extre clearance on the bottom of the lobe. I already inquired about this.

The only way that they can do it is to build the lobes up then grind them down to gain more lift. Probably cost as much as stage 1 cans with not as much gains.

You cant regrind the cams in a 3rd gen because they have hydraulic lifters. All that will happen is the lifter will expand to compensate for the extre clearance on the bottom of the lobe. I already inquired about this.

The only way that they can do it is to build the lobes up then grind them down to gain more lift. Probably cost as much as stage 1 cans with not as much gains.
is there no direct swap cams available even from the US ?

is there no direct swap cams available even from the US ?


thats a great idea, not sure tho. If anyone can shed some light on it i would be greatly appreciative.

remember to get the heads serviced by a head shop before u even consider putting them on your engine

You cant regrind the cams in a 3rd gen because they have hydraulic lifters. All that will happen is the lifter will expand to compensate for the extre clearance on the bottom of the lobe. I already inquired about this.

The only way that they can do it is to build the lobes up then grind them down to gain more lift. Probably cost as much as stage 1 cans with not as much gains.


Yes you can, mine are done, cost 1k all up including valve springs, 420thou of lift instead of 350thou, all tested and ready to go on my engine being built up soon. Giddy Up!!!!!!!

Yes you can, mine are done, cost 1k all up including valve springs, 420thou of lift instead of 350thou, all tested and ready to go on my engine being built up soon. Giddy Up!!!!!!!

weren't you getting billets? also what valve springs did you use?

Yes you can, mine are done, cost 1k all up including valve springs, 420thou of lift instead of 350thou, all tested and ready to go on my engine being built up soon. Giddy Up!!!!!!!


:stoopid:

yeah i was told the same, ppl say don't go regrinds.... after a lengthy discussion with a race cyl head builder he assured me he could have the magna cam reground to whatever i want and guarantee it to be as good as a new billet cam..... technology has slightly improved in the 100years they have been doing this ;)

thats a great idea, not sure tho. If anyone can shed some light on it i would be greatly appreciative.
surprised you haven't thought about these b4 sure it wouldn't be to hard to find out

remember to get the heads serviced by a head shop before u even consider putting them on your engine


Jase, I am the head guy. Thats already on the cards. I'll lap those valves till they cannae be lapped no more!!!

Also, i'm tryin to find lift and duration specs for the pajero cams if anyone can help, and valve sizes too.

I think you're talking about the Gdi pajero engine, which is 162kw

Shame you can't get a 8A80 engine build :(

I think you're talking about the Gdi pajero engine, which is 162kw

Shame you can't get a 8A80 engine build :(

Its not the GDI.
It is a 3.5 6g74 with dohc. Came off an Australian delivered pajero. Trust me.

I hope it fits..............AND works.
Considering they are the heads off the engine i have, which is the other way around, well i hope they work :P
GL

Like i said, trust me, it will work. I will post up pics of the heads this afternoon as i am just about on my way to go and pick them up.


Update!!!
Just arrived home from picking up the heads. What a drive. 560Km...holy cow.

Anyway, took a couple of happy snaps when i got them in the shed. As you can see from the pics, they are identical to the SOHC heads underneath(twin cam at the back, single at the front.) And just to prove i'm not talkin crap, i even dropped one on the block as a test run!!

Crap it does line up....
Man its going to be very interesting to see this come along.

Like i said, trust me, it will work. I will post up pics of the heads this afternoon as i am just about on my way to go and pick them up.


Update!!!
Just arrived home from picking up the heads. What a drive. 560Km...holy cow.

Anyway, took a couple of happy snaps when i got them in the shed. As you can see from the pics, they are identical to the SOHC heads underneath(twin cam at the back, single at the front.) And just to prove i'm not talkin crap, i even dropped one on the block as a test run!!

What are you going to do for an intake??? Judging by those pics, you can throw the lower intake manifold and plennum from the magna in the bin - because they aren't going to fit those heads.

What are you going to do for an intake??? Judging by those pics, you can throw the lower intake manifold and plennum from the magna in the bin - because they aren't going to fit those heads.
looks like you wont be able to throw a sprintex s/c over the top either. There goes any ideas of mine lol

What are you going to do for an intake??? Judging by those pics, you can throw the lower intake manifold and plennum from the magna in the bin - because they aren't going to fit those heads.

Ok according to the research ive been doing
3L lower intake manifold will not bolt on
you will need the pajero 3.5L lower intake manifold to bolt on and then you can use a 3000GT upper intake manifold to bolt onto that.

the 3000GT lower intake manifold wont work though.
but again becuase your engine is facing a whole different way i have NFI if it will work backwards.
I can see if mine work backwards if you want?

another issue besides the ones you have mentioned are the fact that the exhaust ports are massive and a totally different shape to the magnas, and there is nowhere to jam the dizzy in. I will have to get the ignition system off of a pajero.
The only issue i could see with manifold is that the bolt holes didnt line up. Thats a minor detail atm.
I have to do a regrind and service on the heads. I will clean out the ports a bit, cos they are massive compared to the magnas, then fit them up to the block and get a timing belt for it. etc. Intake, exhaust and ignition will come after. If anyone want more pics i am happy to oblige.
I will keep you all posted anyway!!:D

and there is nowhere to jam the dizzy in.

:disgusted

another issue besides the ones you have mentioned are the fact that the exhaust ports are massive and a totally different shape to the magnas, and there is nowhere to jam the dizzy in. I will have to get the ignition system off of a pajero.
The only issue i could see with manifold is that the bolt holes didnt line up. Thats a minor detail atm.
I have to do a regrind and service on the heads. I will clean out the ports a bit, cos they are massive compared to the magnas, then fit them up to the block and get a timing belt for it. etc. Intake, exhaust and ignition will come after. If anyone want more pics i am happy to oblige.
I will keep you all posted anyway!!:D
Probably because it uses a coil pack.
3000GT ones are the same on the 3.5L FIY

:disgusted

Its ok, not as bad as it sounds. I am actually quite a competent and thorough mechanic. I just didnt want to use the technical terms.


Anyhoo kids, i took some more pics of the heads tonight. Some closeups of the exhaust and inlet ports, and some of the standard magnas too just for reference.

more pics

and more pics

Needs a clean....

Awesome work though, can't wait to see how it turns out.

I'm curious as to what you will do for an intake manifold.

Never fear...........

Never fear...........

I like where this is going. lol

Never fear...........
I like where this is going. lol

I'm with you Phonic, lol

I know it needs a clean. I stripped one of the heads down the other day and they are in pretty good condition. I will get the valve seats professionally machined, along with the valves. I may even get them to port and polish it. I will need at least the pajero lower manifold as the bolt holes have a different spacing. The inlet ports are spaced the same and are the same size. Exhaust is obviously different. But with Ez Boy's dad's exhaust shop 100m down the road, i dont think that it will be a problem.


That is all for now. will keep you posted.
Chris

hey screamingTE i was just browsing rpw's online store as you do and i came across these (http://www.rpw.com.au/shop/index.php?option=com_virtuemart&page=shop.product_details&flypage=shop.flypage&Itemid=31&category_id=92&product_id=1322) naturally these are twice the price but thats understandable

hey screamingTE i was just browsing rpw's online store as you do and i came across these (http://www.rpw.com.au/shop/index.php?option=com_virtuemart&page=shop.product_details&flypage=shop.flypage&Itemid=31&category_id=92&product_id=1322) naturally these are twice the price but thats understandable

From the US they are half the price.

hey screamingTE i was just browsing rpw's online store as you do and i came across these (http://www.rpw.com.au/shop/index.php?option=com_virtuemart&page=shop.product_details&flypage=shop.flypage&Itemid=31&category_id=92&product_id=1322) naturally these are twice the price but thats understandable

damn for that money $$$$$$ it'd want to come with Vtec too lol

regrinds ftw :P

']From the US they are half the price.
from the 3sx shop?

from the 3sx shop?

Yeps :D

']Yeps :D
meant to have a good look in it the last time you posted it so now i am just surfing it and dreaming and what dreams they are

Interesting project, although to be honest I'm a bit skeptical about the gains you'll make. Reason being I'm not convinced there's much to gain, when JasonsVRX has proven the regular SOHC heads to be capable of flowing 300 flywheel kw NA (with a fair amount of work of course).

Perhaps with a rebuilt bottom end the DOHC heads would safely allow for some extra revs, always handy for a serious NA build. But I don't see you getting much out of the heads without doing lots of other stuff to match. E.g your cams that come with the head obviously aren't designed for top-end power, are you going to drop in some hotter cams?

Of course I'm just speculating, will be happy to be proven wrong, and I hope it turns out well for you. Eagerly awaiting your results!

Interesting project, although to be honest I'm a bit skeptical about the gains you'll make. Reason being I'm not convinced there's much to gain, when JasonsVRX has proven the regular SOHC heads to be capable of flowing 300 flywheel kw NA (with a fair amount of work of course).

Perhaps with a rebuilt bottom end the DOHC heads would safely allow for some extra revs, always handy for a serious NA build. But I don't see you getting much out of the heads without doing lots of other stuff to match. E.g your cams that come with the head obviously aren't designed for top-end power, are you going to drop in some hotter cams?

Of course I'm just speculating, will be happy to be proven wrong, and I hope it turns out well for you. Eagerly awaiting your results!

The cams he should get a from a 3000GT, they will ROAR. they are made for top end power.
Way i think of it is like this.
Why not have a better building block from the start?
RPW make 500HP Odd from there 3.5L TT SOHC
In the US They are getting close to 1000HP from the 3L DOHC.
the extra cams just let the engine breathe so much easier, no choking to be had at all.
If he can get it to work it would be a forced induction monster.

']Yeps :D
hey tuffy just had a real good look through that 3sx site and i have a few questions, the stealths/3000gt came in both 6g72/74? if that is so what year models are the they respectively? its just that in the site when your are searching through the parts it only displays what year model and not the engine


EDIT: just read your above so they only came out in 6g72? so is there much interchangeable between the 2 or is the top end the most of it?

hey tuffy just had a real good look through that 3sx site and i have a few questions, the stealths/3000gt came in both 6g72/74? if that is so what year models are the they respectively? its just that in the site when your are searching through the parts it only displays what year model and not the engine

The stealths and 3000GT's came with 3 engines
Our 12 valve SOHC 3L
The 24v DOHC N/A 3L
and the 24v DOHC TT 3L
The 3.5L was never an option on those cars.

The 3 and 3.5L share the same heads, its just the block which is different.

']The stealths and 3000GT's came with 3 engines
Our 12 valve SOHC 3L
The 24v DOHC N/A 3L
and the 24v DOHC TT 3L
The 3.5L was never an option on those cars.

The 3 and 3.5L share the same heads, its just the block which is different.

this just answered my edit to my last post

also even with the different block are there any interchangeable parts such as the pistons and rods?

this just answered my edit to my last post

also even with the different block are there any interchangeable parts such as the pistons and rods?

err nah dont think so..
pretty sure the whole bottom end is bigger. or different in some way.

']err nah dont think so..
pretty sure the whole bottom end is bigger. or different in some way.
isn't the difference just a taller block eg .o83cc more in each cyl ? that would help explain the same heads


if so then the pistons would be feasible

isn't the difference just a taller block eg .o83cc more in each cyl ? that would help explain the same heads


if so then the pistons would be feasible
yeah block is 18mm taller.
no idea on the internals mate :P
all i know is they came out stock with a forged crank :D

so off their website will their turbo manifolds bolt onto our 6g motors ??

']yeah block is 18mm taller.
no idea on the internals mate :P
all i know is they came out stock with a forged crank :D
if that is the case then the rods on the 3.5 would have to be longer makes you think how much extra cc you would get if you used the shorter rods.

so off their website will their turbo manifolds bolt onto our 6g motors ??
im gonna say no the reason being have a look at the exaust ports on screaming te's heads there taller and a different shape and also at a different angle if i remember right

im gonna say no the reason being have a look at the exaust ports on screaming te's heads there taller and a different shape and also at a different angle if i remember right

correct...
For any SOHC 12v's who wanna do up there engines there SOHC bolt on stuff is cheap!!
i.e. stainless extractors for $375US
But yeah as toocky said nothing will line up with the SOHC 3.5L

forgive me.. but arnt the 3rd gen 6G72 and 6G74 24 valve SOHC?

forgive me.. but arnt the 3rd gen 6G72 and 6G74 24 valve SOHC?

No. The Magna versions are all SOHC, but the 6G72 has a DOHC version and the 6G74 has both a DOHC and a MiVEC version.

i realise that.. i didn't mention anything about the DOHC versions.. i'm 99.9999999% sure that the 6G74 SOHC in the aussie magna is a 24 valve.. not a 12 valve.. ie they have 4 valves per cylinder.. not 2..

i realise that.. i didn't mention anything about the DOHC versions.. i'm 99.9999999% sure that the 6G74 SOHC in the aussie magna is a 24 valve.. not a 12 valve.. ie they have 4 valves per cylinder.. not 2..
then you would be wrong the earlier magnas (2gen) have the 12 valve 6g72 sohc

i realise that.. i didn't mention anything about the DOHC versions.. i'm 99.9999999% sure that the 6G74 SOHC in the aussie magna is a 24 valve.. not a 12 valve.. ie they have 4 valves per cylinder.. not 2..

In the 3rd gens. Yes you are correct. 3.0L or 3.5L 24V.

Although the 2nd gens are running 3.0L 12V motors...

then you would be wrong the earlier magnas (2gen) have the 12 valve 6g72 sohc

If you read his first question..he was asking about 3rd gens..

If you read his first question..he was asking about 3rd gens..
yea i missed it the first time i read it coz his was last post on previous page

thats what i ment.. 3rd gen ones are 24v..


matty.c
forgive me.. but arnt the 3rd gen 6G72 and 6G74 24 valve SOHC?

lol.. ok then.. just so were clear on that..

Just thought i would add as well, if you need to change the cams in this motor, it would be a lot easier than doing it in a SOHC. Instead of having to remove tha cams via the end of the head, they are held in place by a series of bearing caps, so it would be a matter of removing the inlet, rockers, timing belt and then the bearing caps and viola, cams are out.

Also, those 3sx ones are bloody expensive.

How is this going chief?

I just took a quick peek under the bonnet of my 98 NL Pajero.
It uses 3 coils, with two leads per coil.

From memory the output of a 3.5 DOHC Pajero was 154kw
The SOHC Pajero puts out 140kw.


hmmmm Supercharger?:badgrin:

good luck mate

nah bring on the TT setup with that DOHC! :badgrin:

i agree

but i hope all goes well with this as im watching this with great interest

Hi Chris, I got your email, but am having SMTP dramas so can't reply.

ECU wise, most will do the trick just fine. Even Microtechs have 3 ignition outputs now days and they are very entry level units.

Basically you will be running the stock Cam Angle Sensor (CAS) for triggering. That is the easy part, as it is the same internally as VR4's, 4G93's and EVO Lancers, so very compatable with off the shelf units and configuration files are easy to come by.

Injection would be semi sequential unless you plan to run a very high level ECU with 6 injection outputs. Possible, but a waste of money for very little gain.

Ignition will be simple aswell. As you say it already has coils on plug, so you will need 3 twin channel ignitors to drive the coils wasted spark. Again, you will need an ECU which has 3 or more ignition outputs.

Chosing the ECU is the question, as most entry level ECU's will be capable of running your setup once configured. You have the usual options of Haltech, Autronic, Microtech, EMS, Adaptronic or even a megasquirt.

I am obviously a little bias :) but I do think the Adaptronic e420c is the best ECU for your dollar. Basically the same spec if not higher than your middle range Haltech and Autronics but a fair bit cheaper. PM me for a price, I have sorted out 2 members on here with ECU's now so pricing is even more friendly.

Let me know if you have any more questions or want to talk about it further (that goes for everyone, just PM). I don't really get time to ready through threads anymore, but I will subscribe to yours :) You have my email to. I am more than happy to help on technical questions, its just hard to find them though all the body kit and sticker talk.

its just hard to find them though all the body kit and sticker talk.

:bowrofl: That's gold.

TC: With the massive influx of new members over the past year, most new to car modding, would you be interested in putting together a few technical write-ups on ECUs so people can sort the wheat from the chaff? I know the moderators would be keen to 'sticky' it in the mods area. :cool:

I can answer specific questions but wouldn't know where to start giving a basic write up.

I can answer specific questions but wouldn't know where to start giving a basic write up.

I guess a quick run down on what signals are typically intercepted and why (magna specific), differences between ECUs for natch asp vs forced applications, what features are desirable in both or something along those lines. Even a bit of info in to what/how you tune the cars you've done; AFRs, timing, etc. Just to get people thinking outside the 'bodykits and stickers' square ;)

I guess a quick run down on what signals are typically intercepted and why (magna specific), differences between ECUs for natch asp vs forced applications, what features are desirable in both or something along those lines. Even a bit of info in to what/how you tune the cars you've done; AFRs, timing, etc. Just to get people thinking outside the 'bodykits and stickers' square ;)


or maybe even the Pro's and Con's on major ECU's..
how fast it can be tuned, if you can tune it yourself, cost, what it can control..
i really dont know what im talking about i may be way off but yeah..

Forgot to subscribe... done.

I can answer questions, but have the feeling a guide would fall between the cracks or on to deaf ears. Too small a audience.

nah bring on the TT setup with that DOHC! :badgrin:

I have been periodically browsing the turbo section on ebay, but that will just run into many $$$ that i dont have.

For now, i am going to do a 3.5 SOHC conversion on the car and do some stuff to the DOHC motor for a later conversion. I have 2 3.5s in my garage and a spare set of SOHC heads.

I was thinking Pajero 3.8 pistons or something along those lines. Sound like Jason's ECM system will do what i need it to do, cos i know the magna one wont.