I guess I should start form the beginning. After all the repairs I did last year, I got the engine on the dyno in the spring. The valves always seemed to be a bit noisy (hydraulic flat tappet), more so than the more radical Engle K8 I ran last year. This one is a special grind from FHO (Comp cam and lifters-.499I/.530E, 230
dur@.050, 112 seperation).
Over the course of the summer I could hear a louder intermittant clicking that would just go away on it's own. The lifters always rattle when the engine is first started cold until the oil pressure comes up. More noticeable if you leave it for more than a day.
I recently redid the preload (3/4 turns past zero) and switched from a diesel 15W40 to a 10W30 Brad Penn (I have a lot of oil pressure). Ever since then (two week ago) I've noticed a louder than normal clicking that seems to come on once the engine is at operating temperature. I switched to a thicker Amsoil 10W40 with no change. In the course of a drive (about an hour) I can sometimes hear the clicking getting louder and then getting quiet on and off. I'd also hear this coming of the throttle between gear changes.
I assumed this is from the lifters. Having reached my limit, I ripped the intake off and valve cover (took me 2 hours-unfortunetly I'm getting good at it). The cam looks mint. I had the engine running yesterday afternoon. I tried to push down on the push rods with the back of a plastic hammer. None of the lifters collapsed, but I could spin the push rods on the lifters that are on the base circle.
Seems like the lifters are good, so now I don't know what to think. Could they still be bad? Could it be the rockers (landy rollers with RAS stands)?
I ordered a set of new lifters from John Arruzza. So.....
Should I take the ones that are in there apart, clean them and try again
OR
Should I replace them, re do the break in and hope that solves it.
The engine is torn down enough that I can do either. I'd like to fix this before the snow flies.
Any and all ideas would be welcome.
By the way despite the racket, the engine runs awesome. Plenty O power and torque, great idle, no missing surging or carrying on.