||06-29-2014 07:45 PM
Originally Posted by mjr46
wiped cam is not the only thing that'll do that, you need to run a compression test, then leak down and if that yields no results run a vaccum test and watch needle fluctuation that'll indicate valves not opening far enough then pull rocker rover and watch movement of rockers........bent push rods, bent valves, burnt valves and issues with rocker adjustment can all cause the same issues, so troubleshoot before jumping to conclusions......if it is a wiped cam, either you didn't break the cam in right or didn't use zddp additive for flat tappet cams
Bottom end was rebuild several years ago but I did NOT use a zinc additive. I only learned about modern oils not having zinc only after last Friday night. I do plan to start by pulling the valve covers and inspecting the rockers, pushrods, etc.
Compression readings were between 160-175 only a few weeks ago and vacuum was at 15, with a pretty much steady needle reading, considering the cam it has. This car only fires up before races and when it's at the track. Any other time, it sets in the garage and collects dust.
The only things that have changed within the last several months is the heads getting rebuild (at a good machine shop) and the addition of roller rockers, which I installed and adjusted and had somebody else verify that I did it correctly.
With all this being said, that's why I have it narrowed down to a wiped cam. I'm going to tear it all down anyway, but I'm pretty sure it's the cam and lifters.