2.8L M20 build - Now with 2.7L!

[Cha Ching]

Dude, is it me or does that thing sound like an old fighter plane from WW2 firing up?! Bitchin'!

[camip]

Congratulations I bet you feel like your first son was just born.

[acolella76]

how did the piston sit realtive to the deck? The nominal numbers say it should be -0.5mm (+4.5-5=-0.5) did you measure and confirm this at all?

I only used a vernier caliper ot measure, so not sure how accurate it was, but that is about what i measured.

Also,

[digger]

Got the pistons and everything installed! Sorry for the bad pictures. Looks like the motor is about ready to be dropped in which should be happening next week if all goes well.





Now I just have one question.

I plan on boosting this motor. Right now on the motor that's installed in my car (the one I'm taking the cylinder head from) has a stock thickness MLS gasket. I have heard mixed reviews about the MLS gaskets and if I'm being honest I haven't been all too pleased with it. So would it be worthwhile to switch back to an OEM Goetze head gasket or should I just leave the MLS and spray it with that copper spray?

how did the piston sit realtive to the deck? The nominal numbers say it should be -0.5mm (+4.5-5=-0.5) did you measure and confirm this at all?

[digger]

Curious what everyone thinks about this rod/stroke ratio? I'm in the middle of collecting parts for an M50 2.8 NV and was thinking of using the same items, 84mm M52 Crank, 130mm M20 rods and my M50 NV pistons. The ratio comes out to less than ideal and could encounter some side load issues. What is the history with this combination and how does it fair for a boosted motor?

Thanks,

i wouldnt get too hung up on it. BMW used a 135mm rod in a 89.6mm crank engine with RR =1.51

[LJ851]

funny how things work when done correctly.

qft

[acolella76]

The rod stroke ratio is less than ideal like you said but it's not something i would get hung up about. For 10psi it will be fine I'm sure!

Started work tuesday... got the motor ready to pull, got it pulled yesterday, and have spent all of yesterday/today getting the new motor ready to install. Going pretty smoothly, and should have it buttoned up by Sunday at the latest.

Had some scary moments today though. Put the timing belt on, thought it was timed correctly, kept getting valve-piston contact. I tightened the bolt on the tensioner too much and the belt wasn't tensioning, so the belt was skipping. Got it fixed and no contact what so ever! Funny how things work when done correctly.

Out with the old

StanceWorks


Ye old lump

[mrdezyne]

I recently rebuilt an 885 head. All new valves, new Febi rockers, 272 billet cam, the works. Then tossed it on my 2.7L flat top bottom end and thus created the 2.7L budget stroker that put down 150whp/148tq when it wasn't even tuned. It was fine for a while but I've recently noticed that the rings seem to be letting go of some oil and I decided to rebuild my bottom end. But not just ANY rebuild, I am building it to 2.8L!

Build specs:
M52 crank
130mm eta rods
Short skirt B25 pistons
Hoping to eventually run MegaSquirt

Curious what everyone thinks about this rod/stroke ratio? I'm in the middle of collecting parts for an M50 2.8 NV and was thinking of using the same items, 84mm M52 Crank, 130mm M20 rods and my M50 NV pistons. The ratio comes out to less than ideal and could encounter some side load issues. What is the history with this combination and how does it fair for a boosted motor?

Thanks,

[acolella76]

I finally got the bottom end ready to be dropped in. Oil pump cleaned and installed, installed some studs for the oil pan.



Hoping to get the old motor out Monday or Tuesday, we'll see how it goes from there. Getting pretty excited!

[MR 325]

I despise MLS gaskets and will never run one. I am running the OEM BMW + size gasket on my turbo engine.

[acolella76]

Got the pistons and everything installed! Sorry for the bad pictures. Looks like the motor is about ready to be dropped in which should be happening next week if all goes well.





Now I just have one question.

I plan on boosting this motor. Right now on the motor that's installed in my car (the one I'm taking the cylinder head from) has a stock thickness MLS gasket. I have heard mixed reviews about the MLS gaskets and if I'm being honest I haven't been all too pleased with it. So would it be worthwhile to switch back to an OEM Goetze head gasket or should I just leave the MLS and spray it with that copper spray?

[acolella76]

This thread has great information! Great work on the build Alex, looks fantastic. I'm looking forward to more progress. I've got an M20 in the shed that I am getting real tempted to build now!

Thanks for the kind words! :)


No major work done today, but I felt like doing something so I took apart and cleaned the oil pump. No before pictures taken, but Jesus Christ this thing was gunked up. Can't see how it was even sucking up oil!





Nice and clean now!

[e30nub]

This thread has great information! Great work on the build Alex, looks fantastic. I'm looking forward to more progress. I've got an M20 in the shed that I am getting real tempted to build now!

[acolella76]

sick can't wait to see more progress

Thanks, should be done soon. Going to pick up the rod bolts this week and that is the last of the parts I need. Going to drop the motor in during the first week of March!

[StreetMafia21]

sick can't wait to see more progress