Pushrod selection

69_340_GTS said
Dumb question: Are you adjusting each lifter when it is on the cam's base circle?

Yes, I am doing that.

George Jets said
Lots of people asking about valve stem height.

Here is a simple test to see how close you are to stock valve stem height.

A paint stick, 1 1/8" wide standing up on edge of the head valve cover gasket surface. Valve tips should be close to this height.

If valve tips are .050 to .075 ths below this, would say you need longer push rods to make up the difference.

View attachment 1715585587

Here is another example of a 318 with stock valves, same same:

View attachment 1715585589

Others are saying the base circle on your performance cam is smaller than stock . . needing longer pushrods as a result.

Thanks, I'll check that. They are even height side to side. the thing that has me wondering is that this engine ran great for years with the other lifters. Would the lifter height be different?

dartfreak75 said
Start with the basics and dont rule out anything. What valve springs are you running?
Maybe start with a set of factory rockers just to see maybe its them.?
Sounds to me like the melling lifers are collapsing. Check your preload and make sure it's in spec with those lifters. You can get a adjustable pushrod for measuring for like 13 bucks on Ebay.

Unfortunately I do not know what valve springs I am running. I did have them off with a hand compressor when I had the heads off and I'd say they are even in strength. I don't think I have any weak ones. I did grab an adjustable push rod, I have it at home now, I just thought since I had the adjustable rocker arms the length wasn't critical.

Is there such thing as a known good lifter I can use? I hate to replace brand new parts but maybe that's what I need to do.

Cley