valve tap cold start

[Strawdawg]

Mine does the same, but I am old school with the heavy oil. I'm going to try a light synthetic.

Thinner oil is easier to push back out of the lifter orifice than thick oil....as chryco said, stiff springs will do it with time.

If you have a lifter that makes noise after being shut down after only a few minutes, then it sounds more like an individual lifter problem.

If they are all noisy on a cold start, watch the oil pressure and see if it immediately jumps up when started.  If not, suspect a sorry oil filter with a bad anti-drainback valve.

Wix/napa, Baldwin, and other good brands usually have a better sealing drainback than many.

[AARuFAST]

I was under the assumption that 20 w 50 was for a well worn high milage engine.

Why would you use 20 w 50 oil in a rebuild with tight tolerances?

5 or 10 w 30 should be the way to go for flow and lubircation.

New cars do not come with break in oil anymore.

 

[Strawdawg]

I was under the assumption that 20 w 50 was for a well worn high milage engine.

Why would you use 20 w 50 oil in a rebuild with tight tolerances?

5 or 10 w 30 should be the way to go for flow and lubircation.

New cars do not come with break in oil anymore.

How do you know what the clearances are?  Most machinists rebuild to the factory specs unless directed otherwise...and, if the engine is being built for high performance, they may well build to the loose side for high rpm use because that is what they have always done.

If one selects an oil weight that provides the oil pressure that one deems acceptable for the engine in question, that is about all one can do.

New cars are not the subject as far as I can tell from the prior posts in the thread.

[Jamie]

I have hollow pushrods due to magnum heads
The oil I have tried was 5w30  10w40 15w40  none changed the noises
I hear people talk about lifters having the "mopar" diameter?  does comp cams have a smaaler one?
I still have a brand new purple cam on my shelf with matching lifters, maybe on more cam and lifter swap before I pull the engine?

[Strawdawg]

all lifters that go into a mopar engine have the same diameter lifter. 

[Chryco Psycho]

I disagree that you would have one bad lifter , the ones that are holding the valves open while the engine is stopped are bleed down under the high spring pressure & taking a few seconds to refill with oil causing the pushrod to be too short & tap for a while until the lifter makes up the adjustment . this is not going to change with roller or flat tappet lifters , the only soluton is to get rid of the hyd system & go to a solid lifter cam .