Author Topic: 20psi on M42 (Read 5494 times)

Gunni · « **on:** January 29, 2007, 04:24:27 AM »

Whats needed engine wise, assume I got everything else covered.

2002maniac · « **Reply #1 on:** January 29, 2007, 01:19:12 PM »

custom rods, low CR forged pistons, and a good headgasket should do it.

sheepdog · « **Reply #2 on:** January 29, 2007, 01:55:34 PM »

I would consider o-ringing the block/head. Less gasket troubles.

Gunni · « **Reply #3 on:** January 29, 2007, 01:56:20 PM »

Why diffrent rods aren�t they forged already?
would I be able to run lower compression only?
i.e thicker metal gasket, mill the pistons?

bar73k · « **Reply #4 on:** January 30, 2007, 05:53:29 AM »

rods are fine to handle 20 psi

a steel gasket and lower compression pistons are all you need

you could probably get away with a standard headgasket.

its all in the tune, if you can tune the car well you dont need to go over the top

nuvolarossa · « **Reply #5 on:** January 30, 2007, 06:23:30 AM »

I'm impressed of the power that M42 can put out with near stock internals!

not to hijack thread, but only for comparison:
What's need for make a M44 "20psi capable"? The rods are forged as m42, but crank is cast... it's important that the crank is forged with FI? How much psi M44's crank is capable?

thank you and sorry for hijack.

Gunni · « **Reply #6 on:** January 30, 2007, 06:28:25 AM »

I wouldn�t think the cast crank be a issue as it is by far the strongest part of the engine

nuvolarossa · « **Reply #7 on:** January 30, 2007, 08:11:23 AM »

Quote from: Gunni;18444

I wouldn�t think the cast crank be a issue as it is by far the strongest part of the engine

so, why all say that M44 can't handle boost, that M42 is better because it has forged parts... the only part that M42 have forged more than M44 is crankshaft:confused:

Gunni · « **Reply #8 on:** January 30, 2007, 09:00:17 AM »

I�m sure it�s engine management issue,
as was with the M20 until people started taking control over the ignition
10psi used to be the max on a motronic system wich has been proven wrong numerously

nuvolarossa · « **Reply #9 on:** January 30, 2007, 10:56:47 AM »

but with a standalone/piggyback and a perfect air fuel ratio, low CR forged pistons and eventually turbo rods it can handle 20psi as a M42, correct?

Gunni · « **Reply #10 on:** January 30, 2007, 11:17:17 AM »

it�s possible that by using only lower compression trough a thicker gasket and right timing and afr�s you should be able to run it,

kowalski · « **Reply #11 on:** January 30, 2007, 12:34:04 PM »

so a if someone were to build a stroker with an m44 crank they'd be fine to run >25psi?

nickmpower · « **Reply #12 on:** January 30, 2007, 03:10:39 PM »

well i dont think anyones ever been ummmm brave enough to try

zerofreez · « **Reply #13 on:** January 30, 2007, 05:15:44 PM »

You could get away with thick MLS headgasket technically. If you get the CR around 8.5 or 9.0 to 1 you shouldnt have a problem.

I used to be into the turbo mitsubishi's and they had no problem running 20psi on cast rods and crank as long as you fed it good gas and your tune was good.

2002maniac · « **Reply #14 on:** January 30, 2007, 07:07:03 PM »

Quote from: nuvolarossa;18453

so, why all say that M44 can't handle boost, that M42 is better because it has forged parts... the only part that M42 have forged more than M44 is crankshaft:confused:

I have not heard anyone say that. There is even a bolt on supercharger kit that alot of M44 guys use (DA)