E30 Zone

Done a quick search but can't find the info im lm looking for

Is it possable to use an m40 clutch in an m20 engine and gearbox using the m40 flywheel and starter ofcourse

The reason for my question is I have an m40b18 and I've lost interest in it due to constant running problems,
Iv reacently installed a brand new clutch and havent done any miles in it since installation,
A friend of mine is selling his 325i, the shell is past it but the engine is sweet, it would be a waste not to swap the clutch on the m40 if possible while the m20 is out of the car

All help is much appreciated

You can fit an M20 clutch and flywheel on an M40, so I guess it should fit. Whether an M40 clutch will cope on an M20 is another matter.

It would be a very backward step. The M40 flywheel is a nasty, heavy item, used by BMW to deal with the inherent problems of a four cylinder engine. The straight six configuration doesn't need a flywheel anything like as heavy as this, and fitting one would noticeably dull the car's performance.

9.8kgs of Flywheel, great as a door stop. Was it heavy to smooth out the 4 cylinder engine?

It's not just that it's 9.8kg, it's where the metal is - in a big thick band right around the outside. The crank on a straight six is always under power, so would run, after a fashion, with no flywheel at all. A four cylinder relies on the energy stored in a flywheel to keep it running.