Engine Mounting Angles

[knapmann]

Does anyone know the difference between the m20 and the M42 mounting angles? I was thinking of mis-matching engines and gearboxes...

Thanks!

[DanThe]

its about 10 degrees different, the M20 sits more upright

[B5234FT]

So for the uninitiated, do these fall into familes, like all the 4 pots and all the 6 pots, or all the 2 valve engines and all the 4 valve ones?

What about a Z3 M52B28 for example?

I assume its accounted for in the gearbox bellhousing?

Thanks

[knapmann]

AFAIK M10 & M30 have the same gearbox to engine bolt pattern and M20/50/52/54 have the same pattern,
M40/42/44 have the same pattern as the M20 series but rotated slightly as they sit at more of an angle.

[B5234FT]

That makes sense, thanks! I was curious because of this:

http://www.e30zone.net/e30zonewiki/index.php/Z3

Which under gearbox states:

"Gearboxes can be fitted with their matching engines, but Z3 gearboxes sit at a different angle to their E30 counterparts. This means that modifications must be made to the gearbox mount and shifter mechanism "

[jmc330i]

M40/42/44 and M50/52 (and S5* engines) all have the same bolt pattern and mounting angle. M20 has the same bolt pattern but sits slightly more up right as Dan says, so to use an M20 box on an M52 for example, you need a modified mount and gear linkage.

M10 and M30 match each other but not the engines listed above.

[B5234FT]

Aye, so it's not the z3 that special, it's all the E36 era twin camsalong with the 318is etc. Perfect

[Brianmoooore]

Ignoring the older generation M10 and M30, it's the M20 that's special. The rest of the E30 engines, and the engines in the BMW models that followed, all sit at the same angle.