Super6

I just measured the pushrod length on my BB build and was using adjustable pushrods and checker springs. The plunger spring in the lifter is stronger than the checker spring on the valve, so if you set the pushrod too long, you start to open the valve. So I just extended the pushrod to take all the clearance out, without cracking the valves open.

I now have a pushrod length that doesn't include any allowance for the preload on the lifters. I think I need to add around 0.030" to the lengths I determined. Does that sound right?

Thanks in advance.

MelWff

read this thread

http://www.chevelles.com/forums/showthread.php?t=352913

Super6

Thanks, Mel. From that link, I'm looking at a full turn (0.050" on a 7/16-20 stud is about 0.080 at the lifter.)

I should have said that this is on an aluminum head big block with the T&D shaft rocker system. The adjustment on the rockers is right above the pushrod tip and you only have turn of the screw until you affect the oil flow through the lifter according to the instructions. I'll have to see what the adjusting set screw is on the rocker to see what adjustment I have.

Super6

The adjusting set screw is 20 threads per inch, so 0.050" per turn. So I think I'll add 0.050" to the length I measured and then I'll use 0.030" from the rocker adjustment to get the 0.080" (equivalent to 1 full turn). Cool.