Reply to "roller camshafts"

I have/had two close personal friends each running roller cams on the street. One has a race-only solid roller unit, the other a hydraulic roller. Both worked fine, with initial start-up problems. Even the best cam grinders occasionally need to be reminded of the weakness in the 351-C block- the gigantic oil passages connecting the lifters to the main oil galleys. Too high a lift will shove the roller wheel into the oil galley, creating a huge drop in oil pressure- 16 times per engine revolution! You avoid this problem by either running a shrouded roller lifter with a reduced diameter roller wheel, so the roller has no lifter notch to intrude in the oil galleys, or you use a reduced-base-circle cam, where the entire cam is scaled down so that high lift doesn't put a roller wheel up into the oil galley. Finally, any roller cam uses much shorter pushrods and much stiffer valve springs due to the longer, relatively heavy lifters, and requires a steel distributor drive gear to be compatible with the steel camshaft. Crane now makes such a steel gear for the Cleveland. This all makes the cost of a roller cam system 2-3x the cost of a flat-tappet cam of equivalent power. Full synthetic oil is a good idea for such cams, by the way.