my engine swap. flywheel query?

[daveyw]

hi all. i bought a 316i touring at the weekend off ebay that had the 325i conversion done. the big end bearings were shot so i am in the process of putting another 325i engine in out of my spares car. i am using the gearbox out of the touring as this felt much better than the one in the spares car. it was on the hoist and about to drop it in when a local mechanic stopped by and said i will need to swap over the flywheels as there is a square notch by the teeth on the outside of the flywheel that needs to be in the same position on both engines? i know the notch he's talking about but i think he's talking nonsense but i'm no mechanic so thought i better hang fire and ask you guys. i'll be very annoyed if he's wrong cos i could have had the thing fitted by now! surely its just a case of slotting it together. he reckons this is similar to tdc mark.
cheers, davey.

[Brianmoooore]

Don't know what he's on about, unless it's a reference to the bell housing mounted sensors on the 325e engines.
Assuming it's a 325 box in the touring already, then it's just a straight swap. No square notches that I know of!

[daveyw]

there is a small raised square bit about 5mm square just by the teeth on the flywheel. he reckons its a marker for summat?

[jonbuoy]

Don't know if there is a difference between the earlier M20 than the late one (If that's what he was thinking) but should be a straight forward swap.

[daveyw]

the spares car is a c reg but had an h reg engine fitted to it a couple of years ago by one of the previous owners. mine is a j reg but don't know what age the 1st 2.5 is? trust me to buy a mongrel!

[Templ8e30]

The flywheel only goes on in one position anyway, there is dowel tube on one of the bolt holes in the crank and this corresponds to one slightly larger bolt hole on the flywheel. impossible to get it fitted in the wrong position.

Iirc some early M20 e30's had the crank position and engine speed sensors on the gearbox that picked up on a peg welded to the flywheel, I know the 525e has one.

Later cars don't use it so you could fit either flywheel without problems.

Cheers,

Iain T

[Brianmoooore]

Don't know if there is a difference between the earlier M20 than the late one (If that's what he was thinking) but should be a straight forward swap.

All 325i s are Motronic, but someone could have been swapping flywheels.

[daveyw]

thanks guys. job done. took till 3.30 this morning to get the engine fitted mind you!