My recollection was wrong, All of the RR engines I worked on were C4 both Turbo and Supercharged, I cannot remember the power outputs. Working compressors, generators, or Vickers Vicon or C6's various marks and power outputs from I80 bhp up to 265 bhp I did not come across any SF65 fitted to Vickers tractors they were all C6 engined or I believe some Cummins engined ones were built. Those Cummins engines had the PT fuel system. I think the main difference of the SF65 (Falcon) was it ran with the reduced bore of 5 inch and higher compression ratio in the N/A of 17 to 1.