Prechamber Mod "Flame" Front
Prechamber Mod "Flame" Front
There are 40 teeth on the cam gear, so each tooth is worth 9 degrees at the cam, 18 degrees at the crank. I advanced the cam one tooth on a donor engine, and checked for valve clearance. There was interference at the intake valve that prevented rotation. Right now I am running the cam advanced 5 degrees at the cam which is 10 degrees at the crank and that is all that there is to be had.
Anyone who is looking at a custom cam should really be careful. The valve relief pockets need to be made deeper if any significant changes in cam geometry are being considered.
If anyone has a bad 617a piston, I would be interested in it to cut apart to see how much deeper I can make the valve relief pockets without making the piston too thin, (I have no idea what the oil cavity looks like).
I wanted to advance the cam another 5 degrees at the crank, but there is no way without cutting the pistons.