I came across this in an article on Enginelabs.

"Jesel prefers to use larger diameter cams and larger cam lobes with lower rocker ratios. Higher rocker ratios increase the valve opening rates, but by using larger cams and lobes you can end up with similar opening rates while lowering the loads and stresses on the valve train." and "There is a noticeable difference when turning over a motor with the two different packages — small cam with high ratio rocker vs. big cam lobe with lower ratio rockers. It takes more rotational force to move the high rocker ratio package, and this required force (or drag) increases with rpm. It is our experience that the large lobe/low rocker ratio package provides a smoother, more stable valve train capable of more rpm and providing better durability."

Admittedly, he is talking engines with over 1" valve lift..

I have 3 engines with low ratio rockers, and while i am saving for a Mummert "hot rod in a box" i don't want to spend too much on parts for the 292 i am doing in the meantime. Cams are cheap, and and for less than 500 bucks i can do cam, lifters, valves, springs and collets.

i thought a larger cam may be the way to go while i'm saving for my box of 'get up and go go go'?




South Australia