M102 engine in an E28.

[Gamerx]

Hey everyone, I've got a few questions about the M102 engine. Alright, so I've came across this car it's a E23 745i and it has a 3.2l turbo engine, the car and the engine are in not so very good condition, but I was thinking about rebuilding that engine and putting it in my E28 project. So I wanna know if that engine is good and reliable, I heard the engine once got a cracked head so apparently there's another head on the engine now. Are the M102 and M30 heads the same, any differences? I know both the engine and the car are very rare so maybe this could be my score, let me hear your opinions, appreciate it.

[jc72]

been discussed many times here.

http://www.mye28.com/viewtopic.php?t=16345

Short: not worth it

[marc79euro645]

That was my first turbo swap. What a dog! Low compression and 3.2l just don't get it. I am still using the m102 charge piping with recirc setup on an m106 motor. Still, If I had it all to do over, I'd go with a tcd kit, or a n/a v8.

[Gamerx]

I wanted to take the whole motor apart and build it with a bigger turbo. I'm assuming you guys don't want me to go that way with this motor, right?

[marc79euro645]

Yeah, you don't want a 3.2 with low compression. A m30b34 or m30b35 will be a better choice, or I would look into a v8 with a pan that would fit.

[clongo]

Just get a good b34, put head studs and a MLS on it. Get a TCD kit or build a custom kit using a tubular manifold. The old 745i stuff is outdated and a huge waste of time and $ if you want more than 350hp.

[Hffvdbl]

CLongo knows. he's BTDT

[Gamerx]

B34's are very rare here in my country and I won't find it easily, think I'm gonna still go with the M102, my friend who is deceased would like me to do it. This one will go just for him. So my question is it better to rebuild it to stock engine or put another turbo kit, standalone management? Appreciate for the help guys.

[marc79euro645]

You for sure want to increase compression ratio (7:1 on m102) to about 8.5-9 . The m102 has dished out piston tops,so even milling the head won't get you there. By the time you buy new pistons etc, you could have bought a real motor. The engine mgmt is another problem, and more money.When you get it all done, you won't be satisfied with it.Seriously, I'm just trying to save you the dissapointment.

[Gamerx]

Damn, now I'm again at the beginning. I want to build an alpina-inspired E28 and I want to build an engine that's similiar to it. M30/M102/M106 turbo or no turbo, doesn't matter etc... I've heard the B35 aren't good motors, B34 is very rare, M106 sounds impossible, maybe some of M102 parts would fit to M106 block if could find one? I just can't find the right path to go.

[tschultz]

Everybody here is referring to the USA B34 with low compression.
For you in Croatia, it seems to me the M30B35 makes sense because it has the lowest compression of the euro engines and similarly should be relatively easiest to find.

[Gamerx]

Everybody here is referring to the USA B34 with low compression.
For you in Croatia, it seems to me the M30B35 makes sense because it has the lowest compression of the euro engines and similarly should be relatively easiest to find.

Oh okay, thanks.