While some people do more stroking than others on these forums **cough** I was wondering if anyone has a stroker kit in the Magna and their thoughts on it.


Also, I hear the 3.8L in the Pajero is a direct bolt up to a Magna gearbox. Any one know anything about this? Can the crank and rods from the 3.8 be used in the 3.5?


Someone's gotta know!

i was trying to find this out but most mitsi people have limited knowledge of interchangable components

i was trying to find this out but most mitsi people have limited knowledge of interchangable components
without seeing two motors removed from a vehicle side by side it is very hard to tell, thats why they have limited knowledge on the subject, they generaly only have the original components to replace, but i'll ask a guy i know at a mitsu dealership, to take some measurements of bolt locations if he ever has a 3.8 pajero motor out

what about looking in a parts book at repco or something,and see if some of the part numbers are the same for various components?

I remember Dave (of RPW fame) mentioning something in the past about boring/stroking the 3.5L out to 3.8 but I can't remember if he mentioned what was involved.

I'd like to see a stroked 3.5L on boost. :D

Can't just use the 3.8 block along with pistons and rods? U'd have a 3.8L right?


Another questions; How do you change a bore and stroke of a motor?

Can't just use the 3.8 block along with pistons and rods? U'd have a 3.8L right?
If the engine was the same orientation as the destination vehicle then it would be a good start. Main issues are clearance in the engine bay, engine mounts and fitment to transmission etc.


Another questions; How do you change a bore and stroke of a motor?
Mainly by boring the block to increase the diameter of the bore and using different conrods and crank to increase the throw of the pistons up and down.

If the engine was the same orientation as the destination vehicle then it would be a good start.

Yeah the Pajero engine is North South not East West

Yeah the Pajero engine is North South not East West
Yeah, I wasn't going to tell him the bad news :bowrofl:

The 3.8L has a bore of 95mm and a stroke of 90mm. The 3.5L has a bore of 93mm and a stroke of 85.8mm.

Ive bored my 3.5L 40thou oversize (close to 1mm for the metric people). The largest hi-comp pistons i could get was 60thou oversize (close to 1.5mm).

Ya maybe able to bore it out more BUT that all depends on cylinder wall thickness, the last thing ya wanna do is bore it out and build up the engine, only to have it split a bore when back on the road.

Dave from RPW has said RPW have bored/stroked several 3.5 Pajeros to 3.8 and it's within acceptable tolerances.

If this is wrong Dave, let us know so I don't get sued when someone does it and puts a piston through their block. lol


.

Ya maybe able to bore it out more BUT that all depends on cylinder wall thickness, the last thing ya wanna do is bore it out and build up the engine, only to have it split a bore when back on the road

overbore and then sleeve...

overbore and then sleeve...

At about $80per sleeve to supply and fit x 6 = $480 plus pistons to fit cos i wouldnt just go to the trouble of boreing and sleeveing it to fit 3.8L pistons.
Ya may well go all out and get custom pistons and take the bore out to 98-100mm. :D
Then add the stroker crank and get around 4L

4L V6 Magna, that would pull pretty hard id imagine,

hypothitically u have 2 4L V6's or V8's wateva one with a longer stroke but narrower bore, the other shorter stroke but wider bore, i heard that the longer stroke would be good for bottom end torque, but not good higher up, but if u have a shorter stroke much better for top end power and also the option of higher revs ? is this correct ?

4L V6 Magna, that would pull pretty hard id imagine,

hypothitically u have 2 4L V6's or V8's wateva one with a longer stroke but narrower bore, the other shorter stroke but wider bore, i heard that the longer stroke would be good for bottom end torque, but not good higher up, but if u have a shorter stroke much better for top end power and also the option of higher revs ? is this correct ?

That is correct. Use the 5.7L GEN3 commodore V8 and the ford 5.4L BOSS260 V8, the holden(chev) V8 has a big bore but short stroke and loves to rev from factory. The ford 5.4L V8 has smallish bore but long stroke and doesnt really like revving past 6000rpm from factory.

Its the law of pyshics of a longer stroke/small bore has a a harder time winding up revs BUT in theory it should give more low down torque due to more push on the crank from its long stroke.

The ford motor is techically superior with its quad overhead cams but the "old" pushrod chev design wins hands down in the revability stakes.

woo hooo im right

wats pushrod ? ive heard it so many times but never knew what it meant

woo hooo im right

wats pushrod ? ive heard it so many times but never knew what it meant
in a OHC motor the camshaft is in the head, and can open the valves directly or via rocker arms.
In pushrod or as its otherwise known OHV, the camshaft is in the centre area of the block and requires rods (pushrods) going from the cam up to the heads to work with the rocker arms to open the valves.

That is correct. Use the 5.7L GEN3 commodore V8 and the ford 5.4L BOSS260 V8, the holden(chev) V8 has a big bore but short stroke and loves to rev from factory. The ford 5.4L V8 has smallish bore but long stroke and doesnt really like revving past 6000rpm from factory.

Its the law of pyshics of a longer stroke/small bore has a a harder time winding up revs BUT in theory it should give more low down torque due to more push on the crank from its long stroke.

The ford motor is techically superior with its quad overhead cams but the "old" pushrod chev design wins hands down in the revability stakes.

Good example and to add to that :P

Say both engines are revving at 6,000rpm, the fords pistons would be moving faster because they have a longer distance to travel within the same given time. The forces on a long stroke engines componens are larger therefore limiting rpm.

So with all that theory then, a 3.0l magna with a bigger bore would be one kick arse motor??? :badgrin:

up the top yeah might increase revs and more power up top

So with all that theory then, a 3.0l magna with a bigger bore would be one kick arse motor??? :badgrin:

Yes and no. Both magna engines are a oversquare design (bore larger than the stroke) so our engines are of a good revving design, just like the 5.7L chev in the holdens.

The 3.5Litre bore is only 1.9mm bigger then the 3Litre and the 3.5Litre has a 9.8mm longer stroke than the 3litre.

All I was honestly curious about was using the 3.8L crank and rods to make a 3.5L stroked motor to increase my bottom and mid torque. I don't want to rev the guts out of my car.

I cack at all the buzz boxes that have to rev their chops off to get going. I've driven plenty of big V8s and V6's and I still prefer the torquey ford 351 clevelands and the inline 6's.

More torque down low can let me increase my diff ratio. Better use of torque for fuel econ and power. Esp since I have the 5sp auto.