Question about setting the valve lash. So I'm ok on setting the lash on stamped rockers, but it seems on the pro mags that the spring doesn't compress nearly at all. I'm changing them on the car and i've got my compressor set at 80 psi so it forces the piston to BDC. When I tighten the polylocks, as soon I felt it compress the spring (less than 1/8th turn) the valve moves because I hear compressed air moving through the valve. So essentially I have zero lash. Any ideas?

 

Hmm I dont really understand your question.. You dont have to use compressed air when setting the lash, and the piston should be at TDC when setting the lash.

 

I'm installing rockers. When setting the lash on the stamped rockers it seems the spring compresses a little before the lash gets set. On the pro mags, as soon as the I feel tension on the rocker, it starts to open the valve and I have essentially no lash. Is this normal?

 

I have no idea why you are using compressed air for this, but if it is forcing the piston down, it is going to throw off where you want the cam lobe to be when adjusting. Sounds like you are not on the base lobe of the cam when you are trying to adjust the valve. Go to my Tech Page and use one of the adjusting methods listed.