problems with pushrod length

[syclone0209]

assembling new motor with vortec heads and big valves, behive springs, comp chromemoly pushrods stock length and comp cams pro magnum rocker arms. When i put the rocker arm on the polylock will only turn about one and a half times before starting to compress the lifter. i have a pushrod length checker and it shows about a 1/16 too long. the polylock has the threads recessed about a 1/16 so it isnt helping the problem. can i get a washer the correct thickness and put it under the rocker arm stud or try and get a different polylock, or a different length pushrod?

david hancock
918-798-8002

 

[4C FED]

Re: problems with pushrod length

Start off by getting the correct pushrod length.

Are you using self-aligning rocker arms? If not you need guideplates that will somewhat work like washers. They might add 1/8"-3/16" extra height to the stud.
I wouldn't use just a washer though.

Which rocker arm studs are you using? ARP has 2 different lengths for stock rockers or full rollers. The full roller studs are almost 1/8" taller than the stock rocker stud.

 

[James Thomas]

Re: problems with pushrod length

Hardened washers can be used and are the same as a guide plate but I do agree that you need to make every effort to "do it right". There are different poly locks that can be used but I'm sorry the exact PN escapes me at the moment? Length problems will lead to other problems with the geomerty also. You need to check the rocker tip to valve tip engagement very close to avoid excessive valve guide and stem wear.

________
James