Engine swapped, wont fit. E34 M20 to E30

[Hogstad]

Hey,

Have a kinda weird problem going on..

I removed my stock M20B20 engine yesterday, and put in my new M20B25 wich comes from an E34. I changed the motormounts from the stock b20 over to the new b25. Gearbox is the same.

But now my engine/gearbox is about 0,5-1 inch too far back, so propshaftbearing and gearchangerassembly wont fit anymore. Measured the old block and the new, and they are identical, including where you attach motormounts, so the motormounts are in the exact same spot as before on the b20.

So I really cant figure out why the engine/gearbox now is too far back, as it should in theory be in the exact same place.

Changing sides on the motormounts will only make the problem worse, so thats not it ..

Any suggestions ?

[The Dark Side of Will]

Loosen, but do not remove, the nuts on the top and bottom of the mounts.
Pull the engine & trans forward & see if you have enough room.
Re-tighten nuts.

[Hogstad]

The engine is now just sitting in it mounts, not tightened.. But still, its almost an inch off..

[uturn]

Are the engine brackets aluminum or steel? My 325is came with steel ones. Not sure why it would make a difference but it's a shot.

[SmokeE30]

If your using the stock e30 mount arms and rubbers it should fit in the factory position don't use the e34 stuff

[E30NJ]

Did you figure it out?

[AUS30]

Did you figure it out?

+1 for this, I'm about to do the same swap into an M40 powered coupe. Donor car is also an E34/M20B25/G260

[SubDad]

I'd like to hear the answer too, please.
I've got an M20B20 in the car and an M20B25 on the hoist and I thought wiring would be the issue.

[glnr13]

i thought i read somewhere a long time ago that the e34 m20b25 mounting position is different than the e30 m20b25. Which means even if you swap the mounting brackets you'll be in the wrong position.


edit:
from this thread, post #9: http://www.bimmerforums.com/forum/sh...0#post18027300

It's not inconclusive- the motor mount bosses- (the part of the block casting that is drilled + tapped for the motor mount arms to bolt to) are different. It's a major PITA to try to drill + re-tap these to fit the E30. You would have to drill pretty precisely, if you go too far you end up in the crankcase, too shallow and you won't be able to properly tap the holes for those arms.

again, i know nothing. this is just what i read on the interwebz

[Charlie30]

Revive

So I'm picking up a parts car this afternoon, the block in my 91 325i e30 is trash so I was going to pull the complete engine from this 89' e34 with a m20. Searching this topic for a few days I have read that people have the engine in the car no problem, just need to use oil pan from my old m20 and a few other odds n ends like dipstick and air box, but then the occasional thread like this I stating the blocks from e34 for whatever reason we're cast differently and the motor mounts don't line up. Anyone have any more knowledge of this?

[JeLani]

What mount arms are you using?


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