Vettepartz

I can remember when building the small block Chevys with a new cam we would pick a cylinder, put two solid lifters in it, put some clay on top of the piston where the valves come the closest and then put the head on and assemble the drive componants for that cylinder with zero lash. Next we would turn the engine over by hand a couple times and disassemble. Now we would measure the thickness of the clay and that would give us our piston to valve clearance. If we had 0.100 or more, we were OK. A higher lift cam would lessen this value.
I was wondering if anyone had done anything like this with the LS1/LS6 with either stock 1.7 rockers, or the 1.8 rockers. I just want to find what the max lift cam you can run and still maintain proper P/V clearances.

99 Black Bird T/A

iTrader: (4)

My set up was checked very carefully. My P to V was .075 worse case. No one else has had a 224 cam be that tight. Cam had to be retarded slightly to get .075 P to V, This was using a dial gauge which is more accurate than using clay and it was done by someone that really knows their stuff.

Duration is far more of an issue than lift most of the time.

Intake duration around ~227 to 230 @ .050 starts getting tight in the ~.085 to range

P to V will be affected by at least following:

Cam duration
Cam lift (far less than duration)
How the cam is degreed in (advance/retard)
How much the heads are milled
Spring pressure (test springs are weaker)
head gasket thickness
Pushrod Flex
If the valves are sunk any
Was the block decked.
Pistons
Pistons notched etc
rockers
lifter bleed down (for non solids rollers)

etc