Author Topic: m44 crank to a m42 question (Read 7196 times)

richie_s999 · « **on:** May 13, 2009, 07:22:11 AM »

I have a complete m44 and m42. I am planning on using the m44 crank in the m42. I was under the impreion that it was a strait swap from the 2 motors to use the crank but now I am hearing I have to have some machine work done on the crank.

I am also trying to figure out what i need to do to run the m44 pistons or if I should just use the m42 pistons.

Can those who have used this crank and piston combo please help, I have been through 100's of threads and am coming up confused.

dude8383 · « **Reply #1 on:** May 13, 2009, 01:56:47 PM »

It fits 100%, just make sure the rotating assembly is balanced before you button everything up.

nickmpower · « **Reply #2 on:** May 13, 2009, 04:27:02 PM »

you cant use m42 pistons you will need to bore for m44 pistons

richie_s999 · « **Reply #3 on:** May 13, 2009, 06:09:05 PM »

So i will be boring the block from 84 to 85mm and do i have to shave the m44 piston

dude8383 · « **Reply #4 on:** May 14, 2009, 12:02:03 AM »

Quote from: richie_s999;71834

So i will be boring the block from 84 to 85mm and do i have to shave the m44 piston

i don't recall the size of the m44 piston but i believe its the same as m42 @ 84mm. the m44 changes the stroke on the motor, this is why you have to use matching pistons and rods in order for it to work.

richie_s999 · « **Reply #5 on:** May 14, 2009, 10:51:19 AM »

little more help needed guys, I am new to the stroker motor world, I need to know that with using the m44 pistons and boring out the block to 85mm so they fit, will they have to be shaved at all?? Can anyone let me know what the displacement would be with this sett up and the compresion numbers???

bme30 · « **Reply #6 on:** May 14, 2009, 11:57:08 AM »

hey rich

m44 bore is 85mm so you'll have to bore out the m42 block... OR

from what i have read you can just use the m44 block and bottom end but use the m42 head. the m42 head is better than the m44 head with regards to high revs. i've read this somewhere. if you do a search on m44 build ups you'll read about them using the m42 head and intake manifold.

on a side note rich... i rev at 7k now

richie_s999 · « **Reply #7 on:** May 14, 2009, 03:29:19 PM »

Quote from: bme30;71866

hey rich m44 bore is 85mm so you'll have to bore out the m42 block... OR

from what i have read you can just use the m44 block and bottom end but use the m42 head. the m42 head is better than the m44 head with regards to high revs. i've read this somewhere. if you do a search on m44 build ups you'll read about them using the m42 head and intake manifold.

on a side note rich... i rev at 7k now

did you get the chip done already? Can't wait to hear it rev that high, are you coming to the cruise this weekend?

BeamerIS · « **Reply #8 on:** May 27, 2009, 12:53:39 PM »

Hi i'm kinda new to all this so...
what is an M44 engine ? is this the 8 valve 318 ?

Bmw02er · « **Reply #9 on:** June 02, 2009, 04:54:15 PM »

Quote from: BeamerIS;72487

Hi i'm kinda new to all this so...
what is an M44 engine ? is this the 8 valve 318 ?

1.9l ODB2 evolution of the m42 found in Z3's

BeamerIS · « **Reply #10 on:** June 04, 2009, 07:11:02 AM »

Thanks another thing learned

fabe · « **Reply #11 on:** June 04, 2009, 08:42:35 AM »

so you're ditching the forged steel crankshaft of the M42 for the cast iron crankshaft of the M44??

1991 E30 M42 · « **Reply #12 on:** June 04, 2009, 02:47:27 PM »

the cast crank is fine, i have made plenty of power on mine and havent broken anyting

BeamerIS · « **Reply #13 on:** June 07, 2009, 06:59:27 AM »

how about the bearings of the crank... do you have to upgrade them or
can they handle a lot of power too ?

1991 E30 M42 · « **Reply #14 on:** June 07, 2009, 01:52:02 PM »

i'm using coated race bearings