Interesting. I have seen the PC's in the MB up close and they are different than other IDI engines I have seen. The other IDI's didn't have the steel ball-on-a-stick in the PC and the orifices to the combustion chamber were much larger than the 5 small holes that the MB has. I have wondered what increasing the size of the PC orifices would do for power? Regarding the "severely restricted" rpm range mentioned by psfred I don't follow this logic. How does DI or IDI make any difference to timing advance? Is this not a function of the IP? True old DI engines had restricted powerbands but this was a function of the injection system design, the had a fixed injection timing. If the pump that is being used in this experiment has mechanical timing advance mechanisim then how will the rpm range be restricted? RT

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