Lifter clacking

[timo944]

Oil pressure is great. Feel test is hard to do, It's hard to get the two lifters that are soft coming out of the motor (because they are depressing a valve) to pump up.

I'm a little worried about running it with the current situation. A few weeks ago (after swapping lifters) I had an occasion when it sounded as if a piston hit a valve a few times. This was when the engine was still cold and I cracked the throttle open a hair. After idling for 5 mins and warming up this didn;t happen again. So my belief is that there is a stickly valve. However, as I said before, leak down is OK and the machine shop checked head and claims that every valve is good, no indication of a strike, etc.

So I'm . What to do next?

At least I'm providing good business for the gasket makers.

[Davegt74]

Is this a new rebuild?

The story goes that Zinc was removed from oil and this said zinc is needed in the critical break-in period

I read in grassroots motor sports how David Vazird cured a problem on a GM truck that had lifter clatter using Royal Purple oil

On cam and lifter changes proper break-in is essential
Now more than ever since they removed the zinc

http://royalpurple.com/breakin-oil.html

HTH
David

[timo944]

David,

Appreciate the thought. Yes it's a new motor, though this issue didn't appear until race # 3. I used Joe Gibbs break in oil at start-up and for dyno testing and am now using the Valvoline "racing" 20W50 that is supposed to be high in zinc and other critical materials. I debated trying a different oil but have done so yet...

Tim