decoupe
(deceased)
Where can I find or can someone supply the specs and tolerances of a crankshaft from a 1990 535i. Need to check if one I have found can be used in my m90 block to up the displacement to 3.7 litres.
The attached quote from a X_atlas post (thanks) gives a background to the question.
Thanks
The attached quote from a X_atlas post (thanks) gives a background to the question.
Thanks
I've been looking for the last few days over dicussions about the M30 and M90 engines. (bimmerforums, bigcoupegroup, firstfives, the lot of them) I've been attempting to determine which would work best for a twin-screw kit I've been cooking up.
As far as I can tell, the M90, being significantly oversquare, makes more low-end torque, but dies above 5k or so due to head design.
The M30, however, being a significantly more square engine, (in B35 trim) means it had more even torque over the RPM spread and started to croak at abut 5500 RPM, although I haven't been able to tell if that is because of the larger valves or the displacement setup.
I know the M90 has the advantage of being easily stroked with a M30B35 crank to bring it to ~3.650L, but it also has the disadvantage of head upgrade restrictions and the use of a distributor, whereas the M30 has the later "distributorless" Motronic 1.3 setup and larger valves later in life.
Given how the M90 is based off the M88, I also don't know if the M88 head (not the S38 head) is a bolt-on affair. If it is, that is a very significant advantage to a M90-based engine.
So any other pros/cons between the M30B35 and the M90?