M42 Project started! (S42 Replica)

[Gizmo330iT]

I went to the $tealer and bought an oversize M44 head gasket today to bring the compression down to 11.6:1 for safety reasons, not keen on blowing this motor up any time soon...

DAMN!! The $tealer forgot the KY jelly!!!

[ts295]

11.6:1, cool. what's the bore diameter of the M44 gasket, is it ok with your 86mm pistons?
I take it you haven't had the bottom end back from the machinists yet? bet you can't wait!
how much did the pistons need decking?

[Waxfondlr]

your sir are my new savior..
i wanna hear what this thing sounds like in person when complete..
VIVA m42!!
Bows

[Mr.M]

I less than three you, sir.

[Alpine 318is]

i cant wait for pics

[Gizmo330iT]

11.6:1, cool. what's the bore diameter of the M44 gasket, is it ok with your 86mm pistons?
I take it you haven't had the bottom end back from the machinists yet? bet you can't wait!
how much did the pistons need decking?

The bore diameter of the M42 head gasket is 85mm, the bore diameter of the M44 gasket is 86mm. Yes the M44 gasket works with my 86mm pistons.

You are correct, the engineers are taking longer than I had hoped.

I decked the M3 pistons 3.8mm to get the desired deck height. They were pocketed for the bigger cams and bigger valves which will come later.

[Waxfondlr]

i gotta say man, that all white is the hottest shit ive seen in awhile

[cajunroadster]

Keep up the good work. I've thought about modding my M44 for the last year or so. I'd like to build mine for a DASC application. I'm already getting 11 psi on stock internals, but figured if I could get a higher reving, stronger bottom end, it would be a sweet combination. Thanks for taking the lead and figuring out things for all of the 4 cyl. die hards. Looking forward to seeing and hearing about your progress.

John B.

[Gizmo330iT]

Finally! I spent sat afternoon and most of sunday building the motor and put it in. With no problems besides a noisy power steering pump which I serviced today. Anyway, I took lots of pictures of the build process so I will post them soon. I haven't connected the oil cooler or installed the ITBs or big cams yet. I will do this once the motor is fully run-in.

First impressions, the exhaust tone is alot deeper now, throttle response is friggin' quick and awesome. Im keeping her under 4000rpm and haven't gone WOT yet, THERE'S NO NEED WITH THIS MUCH TORQUE!!!!!! The torque is awesome, a huge improvement from idle to 4000rpm...Feels more than my brother's stock E36 325i...
The idle is deep but stable even with the 300cc M3 injectors and no tuning yet. I just can't wait to get this beast run-in so I can slap the big cams and throttle bodies in....

It feels so good to drive my car again after a month of driving my mom's E39 528i auto, and sometimes my dad's E39 M5...I just forgot how hard my coil-overs were...gotta remember the kidney belt...hehe

I will have the pics up a little later tonight hopefully...

[Mr.M]

Awesome! Congrats on having it running.

[Gizmo330iT]

Keep up the good work. I've thought about modding my M44 for the last year or so. I'd like to build mine for a DASC application. I'm already getting 11 psi on stock internals, but figured if I could get a higher reving, stronger bottom end, it would be a sweet combination. Thanks for taking the lead and figuring out things for all of the 4 cyl. die hards. Looking forward to seeing and hearing about your progress.

John B.

Here's what I see as the ideal bottom end. The M44 block (because it has piston squirters), the M47N 90mm crank, M42 rods (alot stronger than M44 rods, I have some comparison pics) and S50B32 pistons or other forged pistons.

This setup will give you a very strong bottom end with 2115cc.

[Gizmo330iT]

Here's the rods: Left M42, next M44, next M47, last S50


Pistons: Left M42, middle S50 (decked), last STD S50




Pistons in place: (hehe, fingers crossed)


Oil temp sensor tapped into sump:


Ready for fitment:

[ts295]

wow, well done! i'm gald it's all come together

[Gizmo330iT]

The dura form spacer gasket:



Finished product:

[AlaskaBlue]

Congrats on getting it running. I can't wait until you get it all broken in, tuned, etc, and lay down some dyno numbers. I am itching to build one.

[Gizmo330iT]

Im using my car for work now to get her broken-in quicker. I usually use the company car (which is a piece of sh!t) but not for the next 2 weeks. Im a mobile fitment technitian for a tracking company so I should clock up the miles in no time. Gotta get it done before the tuning shops close for the holidays...

[Panzer_M]

I love the setup. Awesome work.

I had to post this up on CFBMW, to show all the 4 haters there.

[jimbolina]

Amazing work. I'm dying to see the results when you get the new cams, valves etc. I WANT ONE!

[T-Rex]

damn thats awesome. nicely done!

[bigbore]

man, just awesome..


my new wallpaper

you have given us ridiculously good info, thank you.

[cajunroadster]

Here's what I see as the ideal bottom end. The M44 block (because it has piston squirters), the M47N 90mm crank, M42 rods (alot stronger than M44 rods, I have some comparison pics) and S50B32 pistons or other forged pistons.

This setup will give you a very strong bottom end with 2115cc.

I believe the stock M44 runs a compression ration of 10:1, and it's been suggested that a supercharged engine should run 8.5:1. Do you think I would still be able to get there using these parts, and not using an extra thick head gasket? I don't know everything about this, but I understand, there is a squish factor to be considered at the top of the stroke, and modifying the gap with gaskets, may not be the best way to go.

Thanks for reply, and keep us posted on your progress as the project moves along.

John B.

[Gizmo330iT]

I believe the stock M44 runs a compression ration of 10:1, and it's been suggested that a supercharged engine should run 8.5:1. Do you think I would still be able to get there using these parts, and not using an extra thick head gasket? I don't know everything about this, but I understand, there is a squish factor to be considered at the top of the stroke, and modifying the gap with gaskets, may not be the best way to go.

Thanks for reply, and keep us posted on your progress as the project moves along.

John B.

You are correct, the M44 does have 10:1 compression. Guys who run 8,5:1 compression boost high numbers with centrifugal superchargers, you have a Eaton M62 roots-type positive displacement supercharger which doesn't like to be over-revved to make higher boost numbers, the thermal efficiency drops quickly and robs you of power. Eventually the coating on the impellers flake off and the S/C is stuffed...

If you are building a custom s/c setup designed to boost high then go down to 8,5:1 compression. Raima on this forum has built a custom M42 S/C setup that producing big numbers, send him a PM.

Other ways to drop the compression with that ideal setup is to offset the small-end bearing, making the rod shorter. The difference between 12:1 compression and 11,6:1 compression was the thicker gasket was 0,3mm thicker than the std gasket, this just shows you how small a difference can change the compression. You could also deck the pistons a little lower to bring the CR ratio down.

[T-Rex]

You are correct, the M44 does have 10:1 compression. Guys who run 8,5:1 compression boost high numbers with centrifugal superchargers, you have a Eaton M62 roots-type positive displacement supercharger which doesn't like to be over-revved to make higher boost numbers, the thermal efficiency drops quickly and robs you of power. Eventually the coating on the impellers flake off and the S/C is stuffed...

If you are building a custom s/c setup designed to boost high then go down to 8,5:1 compression. Raima on this forum has built a custom M42 S/C setup that producing big numbers, send him a PM.

Other ways to drop the compression with that ideal setup is to offset the small-end bearing, making the rod shorter. The difference between 12:1 compression and 11,6:1 compression was the thicker gasket was 0,3mm thicker than the std gasket, this just shows you how small a difference can change the compression. You could also deck the pistons a little lower to bring the CR ratio down.

I propose that you and 94318i4dr share the title of "BMW M4x 4 cylinder guru", he's the turbo specialist, and you build NA monsters

[ts295]

gizmo, whats the piston-deck clearance on a stock M42/M44? thanks for your help, you've been an awesome source of knowledge!
i think i'd like to do something similar to what you've done, would ideally like to run a slightly lower CR tho.

[cajunroadster]

You are correct, the M44 does have 10:1 compression. Guys who run 8,5:1 compression boost high numbers with centrifugal superchargers, you have a Eaton M62 roots-type positive displacement supercharger which doesn't like to be over-revved to make higher boost numbers, the thermal efficiency drops quickly and robs you of power. Eventually the coating on the impellers flake off and the S/C is stuffed...

If you are building a custom s/c setup designed to boost high then go down to 8,5:1 compression. Raima on this forum has built a custom M42 S/C setup that producing big numbers, send him a PM.

Other ways to drop the compression with that ideal setup is to offset the small-end bearing, making the rod shorter. The difference between 12:1 compression and 11,6:1 compression was the thicker gasket was 0,3mm thicker than the std gasket, this just shows you how small a difference can change the compression. You could also deck the pistons a little lower to bring the CR ratio down.

Thanks for the info. I PMed him. I'll work on getting some specs together for my build. I may be back in touch.

John B.