Originally Posted by techwhiz
The e30 M3 used a unique engine block that was a derivative of the M5/M6 of that time and both the 4 cyl and the 6 cyl were unique to the M cars.
There is no other BMW that used the S14 block from the e30 M3.
Sort of true, but the S14 is still an M10 block with M88 heads with two cylinders removed. Semantics really, but the block and 150% of the head was used in all sorts of BMW's.