[Soorena]

Originally Posted by sahara73

M10 block hands down

Folklore tells us M10 engine blocks were also reportedly weathered in the rain and urinated on by mechanics prior to becoming 1500 HP banshees.

http://baurspotting.blogspot.com/201...arged-m10.html

Those M12s are as close to M10 as M49 is to M30. Different heads plus modified blocks to handle the DOHC head. Amazing engines nonetheless.

My vote goes to the die-hard M30. My father still has his M30B34 powered E28, and that engine works like the very first day we received it. 360,000 Kms, not a single major problem. Lots of smooth power (for it's time), amazing reliability and a fairly simple design. The M variants are as great as the M30 is, but they don't have the simplicity of the M30.

And the worst? Hands down the M70.