Originally Posted by chrisdoesntknow
confused.... so it has twin supercharger AND 6.0 conversion? That doesn't make sense, it should be putting up way more than what those dyno charts showed.......
The BMW V12 has a very restricted exaust port. It makes a 90 degree turn directly above the exaust valve with half of the valve guide in the middle of the flow. There is not enough metal in the head to correct this.
The 4 valve M72 engine didn't get beyond prototype stage and BMW chose to build the 2 valve M73 (with the same problem) instead.
A cutaway of the M70 exaust port