As my timiing belt is nearing replacement im thinking about doing a N/A build
so what im asking is what parts are needed to make this happen?

so far i need
stage 2 cams with valve springs
adjustable cam gears
DOHC pajero pistons 1.0mm bigger 10:1
headwork done to match the cams and boring for pistons
rod bolts
hi flow fuel pump

i'll be sending the ECU off for a reflash too

was there anything else that i need?

thanks

when you say "thinking" give us more info. I.e. what is your budget. Because that list there, done by a pro inc labor will be easy over $4000.

budget of about 5g+

;1125671']when you say "thinking" give us more info. I.e. what is your budget. Because that list there, done by a pro inc labor will be easy over $4000.

When I was looking at rebuilding my Evo, I was quoted $3k alone to bore, balance and hone the block.

Then you need to look at prices of cams, pistons, head work, cam gears, rod bolts, fuel pump and a reflash.

For the list of last things I mentioned you'd be looking at least $3k. So we're already up to $6k...

Shave the heads to bump up the comp even more

When I was looking at rebuilding my Evo, I was quoted $3k alone to bore, balance and hone the block.

Then you need to look at prices of cams, pistons, head work, cam gears, rod bolts, fuel pump and a reflash.

For the list of last things I mentioned you'd be looking at least $3k. So we're already up to $6k...

Wow...$3K Alone...jesus..
Mr_Roberto
Cam gears $300+
High flow pump $150-$200
Cams $500
Pistons $400
HG's $100
Timing belt, W/P, tensioner $300
valve springs $400+
Headwork $600+?
Rod Bolts $150
reflash $300?

Thats nearly $3.5K without installation and/or trial of the parts.
If you got the money, sure hunt them down and do it, But remember, whatever you budget for this, it will end up costing about twice as much. happened to me aswell lol

im not too worried about prices mainly what i need
i've got my sources for prices ;)
but thanks for the list Tuff, can already tick some things off :ninja:

;1125749']Wow...$3K Alone...jesus..
Mr_Roberto
Cam gears $300+
High flow pump $150-$200
Cams $500
Pistons $400
HG's $100
Timing belt, W/P, tensioner $300
valve springs $400+
Headwork $600+?
Rod Bolts $150
reflash $300?

Thats nearly $3.5K without installation and/or trial of the parts.
If you got the money, sure hunt them down and do it, But remember, whatever you budget for this, it will end up costing about twice as much. happened to me aswell lol

Bloody hell, you guys would fall over with the prices i got type 40 for his build up.... and that was for someone else to build the engine as well

Bloody hell, you guys would fall over with the prices i got type 40 for his build up.... and that was for someone else to build the engine as well

Don't fancy sharing some of this info - via PM even?

Don't fancy sharing some of this info - via PM even?

Speak to Dave (type 40) he had the prices i got for him.

Speak to Dave (type 40) he had the prices i got for him.

Well to stop type 40 getting 500 different pm's asking the prices why don't you just share here its not as if you are going to be supplying everyone that wants the same stuff but atleast it gives other members prices to work from.Instead of just dangling carrots .

guys this thread is not about who can get what at what price so stop filling it with spam
all i was asking is for a list of items needed for a N/A build with stage 2 cams

Speak to Dave (type 40) he had the prices i got for him.


OK, will do. If needed can you get me the same prices?

I did PM you a while ago...I think I did anyway. :)

bearings for what exactly?

bearings for what exactly?

Crank and rods.

As my timiing belt is nearing replacement im thinking about doing a N/A build
so what im asking is what parts are needed to make this happen?

so far i need
stage 2 cams with valve springs
adjustable cam gears
DOHC pajero pistons 1.0mm bigger 10:1
headwork done to match the cams and boring for pistons
rod bolts
hi flow fuel pump

i'll be sending the ECU off for a reflash too

was there anything else that i need?

thanks

Interested in what you have in mind doing and how much power you want from the engine? No point in doing things and spending money on parts you don't need.

Why bore and fit new pistons? Are the bores flogged out? The benefits of Pajero pistons are overstated, so unless the engine needs oversize pistons its best to spend the money elsewhere.

Same goes for adjustable cam sprockets. Elongating the locating hole with a file will let you set the cams properly for the cost of a round file.

Unless you are going for more than 200kw then you probably won't need a bigger fuel pump.

What do you mean by a Stage 2 cam?

As for costs, a set of cams and valve springs will be $1000-2000 depending on cam and spring specifications, and good head modification work will be about the same $ depending on the condition of your heads. Do valves, seats, guides need replacing?

Cheers,
Alan

Interested in what you have in mind doing and how much power you want from the engine? No point in doing things and spending money on parts you don't need.

Why bore and fit new pistons? Are the bores flogged out? The benefits of Pajero pistons are overstated, so unless the engine needs oversize pistons its best to spend the money elsewhere.

Same goes for adjustable cam sprockets. Elongating the locating hole with a file will let you set the cams properly for the cost of a round file.

Unless you are going for more than 200kw then you probably won't need a bigger fuel pump.

What do you mean by a Stage 2 cam?

As for costs, a set of cams and valve springs will be $1000-2000 depending on cam and spring specifications, and good head modification work will be about the same $ depending on the condition of your heads. Do valves, seats, guides need replacing?

Cheers,
Alan

Alan, Pajero 10:1 pistons are a worthwhile NA upgrade. I have proven that time and time again (Even Steve from SKR agrees on there benefits)

Fuel pumps are very hit and miss, some magna pumps crap out at 130wKw's and some last up to 180wKw's. My stock pump was good for around the 170 mark though. A stock EVO pump (secondhand) is a cheap and easy fitment, the IPR guys run these in there magnas.

It seems he's aiming to build a engine very similar to my donkey build, so if he uses that as a approximate guide then he will do well for minimal costs (decent cams and valve springs will be the most expensive parts to source)

Alan, Pajero 10:1 pistons are a worthwhile NA upgrade. I have proven that time and time again (Even Steve from SKR agrees on there benefits)

Fuel pumps are very hit and miss, some magna pumps crap out at 130wKw's and some last up to 180wKw's. My stock pump was good for around the 170 mark though. A stock EVO pump (secondhand) is a cheap and easy fitment, the IPR guys run these in there magnas.

It seems he's aiming to build a engine very similar to my donkey build, so if he uses that as a approximate guide then he will do well for minimal costs (decent cams and valve springs will be the most expensive parts to source)
haha i did say i liked your car for a reason and was greatful that you posted up a members ride thread ;)
you dont have that list anymore with what you used? unless its still in the thread but i thought you removed it
but yes i am aiming at something similar to your donkey engine, not as wild but not far off ;)

haha i did say i liked your car for a reason and was greatful that you posted up a members ride thread ;)
you dont have that list anymore with what you used? unless its still in the thread but i thought you removed it
but yes i am aiming at something similar to your donkey engine, not as wild but not far off ;)

The donkey engine is surprisingly a very mild and basic freshen up (bore, hone, new pistons/rings, new bearings, ARP rod bolts fitted and the rods resized and a full balance) with basic head (basically some valve deshrouding and just a light general cleanup) and a set of cams.
Cams are the keys to these engines, as myself and the IPR boys have found out over the years.

Alan, Pajero 10:1 pistons are a worthwhile NA upgrade. I have proven that time and time again (Even Steve from SKR agrees on there benefits)

I don't agree in spending that sort of money and having to dismantle the engine just to get a bit more compression ratio. If the heads are modified then they can be milled to get a few points more but the difference between say 9.2-9.4 and 9.8-10.2 is marginal at best power wise with a mild cam. For cruise fuel economy there are a couple % in it, but otherwise more ign and cam advance will give pretty much the same power. Thats not to say in the majority of cases if I could get 10:1 for free I'd knock it back, but I don't advise spending $500 for pistons and stripping the engine. An ECU reflash will give him at least double the increase from the pistons for the same money.

Cheers,
Alan

I don't agree in spending that sort of money and having to dismantle the engine just to get a bit more compression ratio. If the heads are modified then they can be milled to get a few points more but the difference between say 9.2-9.4 and 9.8-10.2 is marginal at best power wise with a mild cam. For cruise fuel economy there are a couple % in it, but otherwise more ign and cam advance will give pretty much the same power. Thats not to say in the majority of cases if I could get 10:1 for free I'd knock it back, but I don't advise spending $500 for pistons and stripping the engine. An ECU reflash will give him at least double the increase from the pistons for the same money.

Cheers,
Alan
so what duration would you class as a mild cam?
the ones im getting are a stage 2 cam which is a 262 duration cam
oh and my cars manual if it makes a difference

I don't agree in spending that sort of money and having to dismantle the engine just to get a bit more compression ratio. If the heads are modified then they can be milled to get a few points more but the difference between say 9.2-9.4 and 9.8-10.2 is marginal at best power wise with a mild cam. For cruise fuel economy there are a couple % in it, but otherwise more ign and cam advance will give pretty much the same power. Thats not to say in the majority of cases if I could get 10:1 for free I'd knock it back, but I don't advise spending $500 for pistons and stripping the engine. An ECU reflash will give him at least double the increase from the pistons for the same money.

Cheers,
Alan

Well i'll agree to disagree with you once again!

If the person is wanting to rev the motor hard frequently (especially with cams and head work in a manual FWD) then the stock rod bolts become a bit suspect, SO to fit better bolts the engine gets disassembled anyway THAT is when its feesable to fit the pistons. Why do a half assed build? and dont go on about wasting money, as i reckon spending $1000 on headwork for a "mild" engine build up as a waste too.

Alan you have a go at me for doubting yours (or your ghost Mr Bells views) YET you are no better by continually cutting me down DESPITE me building enough of these engines over the years to know what works and what doesnt.

FYI the first engine i built had 10:1 comp without using pajero pistons, this was done by shaving 1.2mm off the heads (and .6 of each side of the lower inlet manifold, so it would "seal" correctly), i did do a piston change but only to factory NAS pistons which i aquired thru my contacts at MMAL.

What your saying above is MMAL may as well have just milled a bit off the heads (to get there 9.4:1 comp), throwin in the ralliart cams and presto a cheap for them to build ralliart magna engine.....

I really think you need to get in contact with Rod Campbell (ex mmal engine guru)

It's not a half assed build. Its a build depending on how much money the owner has. If he only has money for cams and heads so be it. by touching the bottom end you put the "on-road" date of the car forward MANY weeks and the project will also cost ALOT more too. Some people just dont have that money and want the car to be off the road that long (if they are using the original block)

I dont see whats wrong in just doing the heads and cams.

Im keeping a very close eye on this thread...

;1127075']It's not a half assed build. Its a build depending on how much money the owner has. If he only has money for cams and heads so be it. by touching the bottom end you put the "on-road" date of the car forward MANY weeks and the project will also cost ALOT more too. Some people just dont have that money and want the car to be off the road that long (if they are using the original block)

I dont see whats wrong in just doing the heads and cams.

I think you mean 'push the on road date backward' not forward lol

I'd have to agree with you Paul... Even with 7psi of boost going through some people's engines with stock bottom ends, rod bolts haven't given out IIRC? Problem was the jelly-like piston crowns wasn't it?

I know if I do a light build on my engine I won't be touching the bottom end. What a **** around lol

;1127075']It's not a half assed build. Its a build depending on how much money the owner has. If he only has money for cams and heads so be it. by touching the bottom end you put the "on-road" date of the car forward MANY weeks and the project will also cost ALOT more too. Some people just dont have that money and want the car to be off the road that long (if they are using the original block)

I dont see whats wrong in just doing the heads and cams.

Whilst the heads are getting done, the car will be off the road. IF the build id planned correctly then there will be NO additional time of the road getting the bottom end done!

Tuff, why do u post up when as uve said before that you dont really have much idea on what is involved in doing a engine build up?

Doing the bottom end up wont cost much in the overall scheme of things and even more cost effective if the top end gets built and then due to the motor being more free revving and likely to get a "thrashing" it drops a rod bolt or spins a bearing then its back to square 1 with alot more cost than doing it right the first time.

I think you mean 'push the on road date backward' not forward lol

I'd have to agree with you Paul... Even with 7psi of boost going through some people's engines with stock bottom ends, rod bolts haven't given out IIRC? Problem was the jelly-like piston crowns wasn't it?

I know if I do a light build on my engine I won't be touching the bottom end. What a **** around lol

High Revs kill rod bolts not boost, a NA motor is more likely to be revved harder more frequently due to the nature of NA engines compared to a boosted setup..

Boost does piston ring lands/crowns though.

For a light build up (extractors, mild cams, etc) as you say, you are correct i personally wouldnt touch the bottom end either BUT Mr _Roberto wants a bit more than a "light" build up

Whilst the heads are getting done, the car will be off the road. IF the build id planned correctly then there will be NO additional time of the road getting the bottom end done!

Tuff, why do u post up when as uve said before that you dont really have much idea on what is involved in doing a engine build up?

Doing the bottom end up wont cost much in the overall scheme of things and even more cost effective if the top end gets built and then due to the motor being more free revving and likely to get a "thrashing" it drops a rod bolt or spins a bearing then its back to square 1 with alot more cost than doing it right the first time.

I've done my fair share of hands on stuff and my fair share of reading on this subject too.
Thing is, to you, who has done this x amount of times, of course its going to "not cost too much more" and "not be too hard"

To Magna Joe Blow wanting to get some more power from what I've read it's pretty unnecessary to touch the bottom end. Specially since the Majority of people on here would be paying for someone else to do this, it will end up costing alot more. HRD2GT has his 220K motor to 7KRPM all the do-day-long, He hasnt broken anything inside, and I doubt even with a built motor you'd be spinning it past 7KRPM. Just one example of course, But with a $5K budget there-abouts for Mr_Roberto, if he is paying someone else to do his work, he wont get much done for $5K.

Remember your only going up...0.6 CR? for a whole bottom end rebuild? Screw that. Mightaswell get some Higher CP pistons made up.

;1127110']I've done my fair share of hands on stuff and my fair share of reading on this subject too.
Thing is, to you, who has done this x amount of times, of course its going to "not cost too much more" and "not be too hard"

To Magna Joe Blow wanting to get some more power from what I've read it's pretty unnecessary to touch the bottom end. Specially since the Majority of people on here would be paying for someone else to do this, it will end up costing alot more. HRD2GT has his 220K motor to 7KRPM all the do-day-long, He hasnt broken anything inside, and I doubt even with a built motor you'd be spinning it past 7KRPM. Just one example of course, But with a $5K budget there-abouts for Mr_Roberto, if he is paying someone else to do his work, he wont get much done for $5K.

Remember your only going up...0.6 CR? for a whole bottom end rebuild? Screw that. Mightaswell get some Higher CP pistons made up.

well let me tell you something Tuffy

I got a quote to build up a engine for Type 40 all up it was just under $4000 and this was done by a well known drift engine builder here in SA. Labour charges to assemble the engine together was a reasonable $1200, as ive said before people on the eastern states seem to get raped with the labour charges


For under $380 for a complete set, the pajero pistons and rings are spot on for 98% of people on here with there NA builds.

Oh and your actually going up 1.0 CR (9:1 to 10:1) which is what MMAL wanted to do with the ralliart but the cardigans put a stop to it lol

Oh and one other thing. Doing a piston change aint that hard (if the heads are coming off the engine), remember TZABOY did a piston change in his driveway with the engine still in the car. If the stock bores are ok then fitting the pajero pistons in a similar way to how TZA did a piston change, is a even cheaper way out IF costs are a issue

I have to agree with Jason here,

I just typed a whole lot but bumped the computer and lost it all :( but here is a summary of what I typed

For starters, if you are going to spend to have an engine that revs hard, you need to spend the money that is required to make it bullet proof or if you do not have that sort of cash you need to save up more money

Jason states that the cost is not that much more when you are doing the heads and I agree with him here. There is no way a pair of cams and head work will cost $5k. Give a couple for the bottom end, even if just to strengthen it up then you have a motor that is worth doing. The simple thing is if it is worth doing, it is worth doing properly.

In relation to Amin, he has not increased any compression, you do this and rev hard and you will stretch the crap out of your rod bolts and they will let go. I am surprised with Amins motor to be honest as it has proven to be a very clean and strong motor, it is in a way a bit of a freak engine and I would like to see other motors do this in standard trim

Other note, a standard 6g74 does not give good power at 7k so reving a stock motor to that point is pointless

On Jason's note of boost, agian 100% correct here. A high reving engine is very different to a boosted engine as you do not tend to rev a boosted engine like a NA engine.

What issues do high reving engines have, the acceleration of the moving parts as they go through a sudden change in direction

As for boost, a standard 6g74 will quite happily run 12PSI with no issues, below are some pics of an off road buggy running 12PSI on a bog stock 74 from a TW that had done close on 100K before it was put in this buggy.

http://i694.photobucket.com/albums/vv303/xtwagon/Parts/IMG_6390.jpg

http://i694.photobucket.com/albums/vv303/xtwagon/Parts/IMG_6391.jpg

http://i694.photobucket.com/albums/vv303/xtwagon/Parts/IMG_6392.jpg

im with jas on this one. once the heads are off its that much more to have the bottom end in pieces. basically once the heads are off drop the sump. unbolt the conrods and slide the piston up through the boor. drop the crank. machine boor. refit cank. fit new pistons with new rods and bearings. refit sump.

edit-mal beat me to it

Also, if you are doing in car as you are really concerned about the extra 150 to remove the engine, if your bores are fine you can hone them with the crank in with no issues

Pistons do not cost the earth, even fitting the pistons to the rods is not expensive, about 30 bucks a rod

Also, if you are doing in car as you are really concerned about the extra 150 to remove the engine, if your bores are fine you can hone them with the crank in with no issues

Pistons do not cost the earth, even fitting the pistons to the rods is not expensive, about 30 bucks a rod

Fitting 3.5 pistons to the rods are even easier than the 3L, as the 3.5L use "seagar" circlips to hold the gudgeon pin in so just remove circlips, heat the piston/small end of rod up to approx 70Deg and push then gudgeon out by hand. They are not a full "press fitment" like the 3L. :)

Fitting 3.5 pistons to the rods are even easier than the 3L, as the 3.5L use "seagar" circlips to hold the gudgeon pin in, they are not a "press fitment" like the 3L. :)

Even better then, I have not done the bottom end on a 3.5 as have had no need

So there to the nay sayers, is even easier to do given that the rods do not need to be heated so why the hell would you not spend a few hundred bucks on a better set of pistons and some decent bolts FFS

Even better then, I have not done the bottom end on a 3.5 as have had no need

So there to the nay sayers, is even easier to do given that the rods do not need to be heated so why the hell would you not spend a few hundred bucks on a better set of pistons and some decent bolts FFS

I added more info to my post Mal. The rods do need to be heated but only to 70degrees, so a very hot tub of water does the trick.

What does shotpeening of the rods usually cost? Better off to buy stronger rods for an NA project? Banana conrods would be bad...

Well i'll agree to disagree with you once again!

If the person is wanting to rev the motor hard frequently (especially with cams and head work in a manual FWD) then the stock rod bolts become a bit suspect, SO to fit better bolts the engine gets disassembled anyway THAT is when its feesable to fit the pistons. Why do a half assed build? and dont go on about wasting money, as i reckon spending $1000 on headwork for a "mild" engine build up as a waste too.

Alan you have a go at me for doubting yours (or your ghost Mr Bells views) YET you are no better by continually cutting me down DESPITE me building enough of these engines over the years to know what works and what doesnt.

FYI the first engine i built had 10:1 comp without using pajero pistons, this was done by shaving 1.2mm off the heads (and .6 of each side of the lower inlet manifold, so it would "seal" correctly), i did do a piston change but only to factory NAS pistons which i aquired thru my contacts at MMAL.

What your saying above is MMAL may as well have just milled a bit off the heads (to get there 9.4:1 comp), throwin in the ralliart cams and presto a cheap for them to build ralliart magna engine.....

I really think you need to get in contact with Rod Campbell (ex mmal engine guru)

Jason you claim I have “cut you down” and “have a go at you”. Show me where I did that in any of my posts above? But you seem to be right into that sort of thing. And why bring Graham Bell into it? Whats he got to do with this?

The member asked for advice. He didn’t mention anything about revving the guts out of the engine or about going to use premium fuel. And the tune he suggested seemed pretty mild to me. At Mitsubishi you must surely has seen the engine destruction testing that goes on to test rods and rod bolts. I don’t know what they did in Adelaide but I do know what we did at other manufacturers during 200 hr and 400hr destruction testing.

For those that don’t know I’ll explain. Just ordinary engines are pulled from the engine line. Different manufacturers use different routines. At the start of a new engine programme they might test 1 in every 100 engines, for exotic cars its 1 in 10, 1 in 20. Then as production matures it might go to 1 in 400, then 1 in 1000 etc. The selected engine is carefully run in at fixed rpm and load for 2 to 4 hrs. Some makers cycle the revs. That’s what I suggest but some use fixed rev and load points that increase every 20-30 min. When run in the engine oil is changed and its inspected for cam lobe wear, and ring blow by measured etc. Then the thrashing begins that will last continuous for 200 hrs. Only the oil and filter will be changed. If its factory filled with mineral oil then it will probably be changed every 33 or 40 or 50 hrs. Porsche use Mobil 1 so its only done at 100 hrs. During that 8 and a bit days the engine will be held at full throttle and usually the dyno will be loaded to keep the engine revs at about 200-500 rpm above max HP revs. The water temp will be allowed to go to 120-130 deg C and held there for 2-3 days and the oil temp will be 150-160 deg, and I’ve seen up to 180 in some cells.

At the end of 200 hrs some manufacturers strip and measure everything and then reassemble the engine without replacing any parts. Others just start into the next 200 hr test without touching the engine. During the 200 hr rpm cycle test the engine will be cycled between idle and 200-500 rpm above the usual rev cutout for the 8 days with different dyno loads and throttle positions. In each cycle they will be held, generally for 2 min at a time, free-wheeling without any load at above the normal cutout rpm to test rod and rod bolt strength and endurance. (There are other tests I won’t go into now.)

Mitsubishi must surely have done something like this so why recommend replacing the rod bolts in a mild street engine and then use that as a reason to fit Pajero pistons? My Magna cutout is at 6800-6900 so I presume Mitsubishi no-load tested to at least 7000-7100rpm. The bolts look strong enough to me. It’s the rods that look a bit sus but in another thread Dave said that for racing they only use the later skinny factory rods and bolts. So if the race guys can run without problems why would a street car that will seldom get to 7000 need better parts?

As for piston replacement being cheap, I would like to know where you can get pistons, bore the block 1mm like the member asked about, hone, and do a piston and rod alignment for less than $1000. And to suggest that Pajero pistons with new rings be fitted in a used bore without a hone in a performance engine. Really? To quote you “Why do a half assed build?”And no mention of a piston and rod alignment? Even second rate reconditioners know to do that.

Where did I ever suggest MMAL just mill the heads for the Ralliart Magna? Obviously when you are doing hundreds of engines from scratch you would fit pistons to give the CR required.

Nowhere have you presented any details of how much superior a 10:1 CR Magna is. You are happy to knock the “cardigans” for only going with 9.4:1 but where is your evidence that 10:1 was far better? I suggest that on ordinary 91 unleaded, basically the only fuel available in lots of Aust at that time, torque would have been down on the 10:1 engine.

For members wanting to learn about this, compression ratio and engine volumetric efficiency (VE) are tied together. If an engine isn’t breathing well enough to fully fill the cylinders then its VE is less than 100%. When the VE is high then you don’t need a high CR to get good torque. That’s why a blower or turbo engine may only accept 6:1 CR and lose HP at anything higher. Its also why engines with restricted breathing need a high CR to make decent HP. NASCAR plate engines years ago were 17:1 (rules now specify max of 12:1) and F3 vary between 15-16:1 because of breathing through tiny 23mm hole. With restrictors turbo petrol Audi/Bentley Le Mans engines are running 12.2:1 CR and even with 4.0 Bar boost (absolute) WRC engines are at well over 10.0:1 CR.

So when it comes to CR you can’t just pick a number. It will depend on engine design, fuel characteristics, and engine breathing (VE).


Engine design – small bore under 85mm, small shallow combustion chamber, alloy head, water temp under 80deg and oil under 100 deg, and port fuel inj (or direct fuel inj even more) means you can have higher CR.
Fuel – more octane, excess fuel (rich) means you can have higher CR
Engine breathing – poor breathing (low VE) means you can have higher CR


Most stock engines run higher than ideal CR because they spend most of their running with the throttle just a bit open. That only lets a little air into the cylinders so the VE is poor. To get respectable cruise fuel economy and torque the car makers then raise the CR. The trouble then is with wide open throttle the CR is too high and the fuel octane too low. To avoid engine damage they map the ECU to richen the mixture and reduce the spark advance, and if it has moveable cams retard the cams more too. That saves the engine from damage but reduces absolute engine torque/HP by anything up to about 10%.

Back when on the Northstar programme the suits decided that the expensive option engine sales weren’t high enough. Part of the problem was that the Northstar was a very high output engine developed to run 98 fuel on 10.3:1 CR. And unlike its inferior 2 valve pushrod cousins it had high VE over a broad rpm band. The suits wanted the engine to be detuned for cheaper 93 octane without any physical changes to the engine, just remapping. The thinking was that being DOHC, cam rephasing and ign retard should be all that’s required. After months of work no matter how much cam juggling went on the ign retard and fuel enrichment needed for 93 RON reduced peak torque 8% and the average torque loss was 5-6%. Finally the suits agreed to allow a CR reduction, but even with a redesign of the combustion chamber it wouldn’t produce an acceptable torque curve at anything more than 9.8:1 CR. At 9.8:1 it was only 1-2% down on average torque compared to the original engine. Later we decided to see how the new low CR engine would go on 98 octane. Unsurprisingly it gained torque everywhere, but surprisingly it was even better than the original 10.3:1 engine ever was. The new engine was released as 2 different engines, identical internally but dressed differently with distinctive cam covers etc. The base model engine went into the cheaper models and the owners manual stated 93 octane and above to be used. The premium model went into the performance models with owner’s manual notation stating 98 octane to be used. When road testers questioned the power differences between engines they were told the engines had exhaust system and inlet cam differences.

Here in Aust 5ltr V8 Supercars are allowed only 10:1 CR even on E85, a fuel where 13-15:1 CR would be more usual, and make 670-680HP. Even with big cams, 260 deg duration @ 0.050” lobe lift and 22mm valve lift ( in a Magna a cam like that with lift reduced to 15-16mm would make 550HP) the engines have massive torque at low rpm and easily wheelspin out of corners at 3500rpm. So big cams, often the reason given for needing a high CR, aren’t killing off low rpm torque.

In NASCAR Nationwide and Truck the engines they are limited to 9:1 CR, a tiny 390cfm Holley carb, like you would use on a Valiant or V6 Capri, and mechanical distributor. Yet they produce 630HP from a low tech 5.8ltr 2 valve pushrod engine.

At the other end of the spectrum some Superbikes racing in Aust have a different problem. The R6 Yamaha (600cc) has to run 11:1 CR but is always on the edge of destroying itself so tuning the engine is a knife edge like a 2 stroke. It wants more fuel to stop detonation but a slight weather change and it loses masses of torque and becomes dead slow.

So how do these few examples apply to a Magna? Well the Northstar teaches that in a nicely developed road engine output is more affected by available fuel octane than small CR differences. Also if the fuel isn’t of sufficient octane for the engine then a lower CR is a better way to keep up the torque and avoid detonation, than reducing ign timing, richening the fuel, and retarding the cams.

The V8 Supercars and NASCAR Nationwide/Truck engines show that with CR that are very low, good HP is available with smart cam choices. From my experience with hundreds of different engine types I would expect there would be less than a 1-2% difference, in other words hardly measurable on cheapo engine dynos like the common Superflow models, between a 9:1 and 10:1 Magna engine on 95 octane with the right cam and head work.

Jason why do you say “i reckon spending $1000 on headwork for a "mild" engine build up as a waste too”? If a cam is the heart, then the head is the soul of the engine. It’s the head that really determines the basic character of an engine and it’s the head that lets the 6G74 down. (The 6G75 is far superior but still responds well to a bit of work). If the head doesn’t need any work why did the “cardigans” allocate funds to flycut the chamber for the Ralliart Magnas? E & D guys spun them a yarn did they? At any rate the members head would need the ex valves refaced/replaced and seats recut even if left stock. That alone is $500 of work. Again to quote you “Why do a half assed build?”

As for contacting Rod Campbell to learn about Magna engines, I don’t think there would be much point. Magna engines are not unique. I have engineered and developed hundreds of different engines and I’ve trained up many E & D guys like Rod, so with respect to Rod he might be able to fill me in with interesting stories of what went on there but as for better understanding engines in general I‘d say most unlikely.

Cheers,
Alan

Mahle 10:1 pajero pistons $ 360
Bore and hone block (using a torque plate) $180

Thats some of the prices attainable here in SA

Now I NEVER said to fit new pistons and rings to used bores without giving the bores a hone!
When i said the bores being "ok" i meant for roundness/taper from top to bottom and I simply used TZABOY's fitting of new pistons and rings in hes own shed without complete engine removal as one way of doing it. I personally wouldnt do it that way BUT he showed it can be done and for a cheaper price labour wise, IF people wanted to go that way.

As for spending $1000+ on head work.... Well thye head work on my donkey heads is approximately $500 worth and they sure dont have any issues in helping the engine make 200+kws at wheels and good midrange torque.

Alan YOU have your "mindset" stuck in a Auto AWD magna which need lots of lowdown torque etc to overcome the sluggish auto and weight (plus more drivetrain loss), Mr_Roberto's magna is a Manual FWD just like mine. We dont need any extra down low grunt as traction is already a issue with a stock engine.

Im NOT going to argue with you anymore BUT i have had great outcomes with my Manual FWD magna engine builds. I know fairly well that my combos may not be suited to a Auto AWD but I HAVE NO interest in that style of magna. End of story.

I think that everyone needs to step back and take a long breath here

The issue here is that we have 2 knowledgable people, looking at 2 totally different cars and 2 totally different points of view.

Alan may be correct in so far as the AWD set up goes as to Jason's point this is not a question for an AWD car, it is a FWD car

I do not get any idea where the question of plonking new pistons in old un prepared bores comes from as Jason did not in any way, shape or form even suggest doing that and if I am reading this thread correctly Jason did even mention honing bores while the engine is still in the car. May not be the way I would do it personally HOWEVER that is why we all do things differently and we develop these cars more and more. If we all stuck to the way one person tackled the build we would still all be running Astrons

I think that this thread has been a great read for both schools of thought, just remember given that both parties have had good results from different ways of acheiving better performance, it does not really mean that one is right and one is wtong, it simply means that we have 2 individuals with different points of view and further given that both are actually talking about totally different cars, both may be right

Peace all

i agree that this thread has been a good read, lots of good info posted

now back to the build, so far the parts i have sourced/located are:

RPW stage 2 cams with shim kit and springs
adjustable fidenza vernier cams gears
steel head gasket
ARP rod bolts and mains
high tension head bolts
walbro fuel pump
pajerp 10:1 1.0mm oversized pistons

anything else that i need? (i know i need bearings and timing belt kit)

clutch?

Are the cams from RPW's new supplier Camtech?

clutch?

i'll give you clutch in a minute :P
clutch is fine i dont know what your on about, tho if the engine comes out might be a good time to do the clutch and engine mounts hmmm


Are the cams from RPW's new supplier Camtech?

no idea mate

no your clutch just stank for 3 days, nothing out of the normal :p

They changed from Tighe cams to CamTech. Would be interest in the quality.

may i ask why you want a steel head gasket? 6G72 DOHC TT motor's that run 10's still use OEM headgaskets, people swear by them and use nothing else

no your clutch just stank for 3 days, nothing out of the normal :p

it still works doesnt it?
i've done worse before then what i did on the weekend
when i mean worse, i mean really stunk
i'll keep an eye on it tho, if it remains for a few more days then i'll get it checked out
doesnt seem as bad now
3 days? i'll give you 3 days more like 2 :P


;1131100']may i ask why you want a steel head gasket? 6G72 DOHC TT motor's that run 10's still use OEM headgaskets, people swear by them and use nothing else

they might be standard ones, i cant remember
i'll have alook tomorrow