to ruin it for the small amount of gain its not worth it but it seams odd all the cars that have run them forever with no probs. Also remeber the 750 and 850 BWMs are two small six clinders linked at the crank hummm I mean two motors two ignition systems two sets of head evry thing off one crank could this be the prob with bmw V12s? I dont know just trying to make sure to be informed.