Quote:
Originally Posted by Alan Roehrich
Jim,
Have you tried different length pushrods? What pushrods and springs are you using?
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Just helping a friend with his 396/L-89 build.
Comp push rods with springs set at 135lbs on the seat and 330 over the nose, "per seat pressure rule" with duel springs with dampner. We just need it to control the valves tight to 6600rpm. We are hoping to run a trap speed of 115mph+ with a 26.9" polyglas tires, 4.10 gears, TH400 , in a 1969 DP 300 deluxe chevelle. Running the infamous manifolds with x pipe for exhaust.
Currently on the road and when I asked him over the phone about his 0 lash lift he said I don't know, I'll call ya back. The lobes on the camshaft should of given him something very close to the max lift if the rocker arms were correct of .530........ Anyway, he called back and he ended up with .511oooops! The conversation continued and after a total of 4 rocker arms on the same lobe he ended up with the .511 with the stamped Nitro's, .514 with a Summit stamped rocker, .527 with a harland 1.70 roller rocker, and a .536 with a 1.72 comp roller........ Anyway, I wasn't there for his pushrod length but he says they are right on with the dry marker on the face of the valve right down the middle with a ware pattern!!!
He is going back to make sure the rocker arm studs are right. Aluminum heads are going to flex more than a cast iron but we are scratching our heads falling so far short on the lift. I'll take any thoughts on trouble shooting this thing..! We're running behind schedule but want to do it right. Thanks again. Sorry for the ramble!
Jim