Lifter, piston slap, bottom end, general aggressive valvetrain, other?

[Cobra4B]

Figured I'd get some input from the knowledgeable people on here.

347 SBF stroker with AFR 165s, custom cam, Pro-systems carb etc. etc. in a Panoz. Trying to help my father nut/bolt the car and it was making more noise than I generally like (I race a Z06 and know LSXs better than anything).

Shortblock was purchase used and completely rebuilt by a very reputable shop. Car ran good this spring but cracked a valvespring at VIR in July. Heads were gone through and freshened up. Then in October it chucked the water pump pulley on track.

The noise really sounds like it's coming from the center of the engine. Initially I thought it was more from the front, but after running it with both VCs off I'm not so sure. I put each piston to TDC and checked the pushrods and rocker arm adjustment and found no indications of a weak or collapsed lifter.

Thoughts? General noise from an aggressvie aftermarket valvetrain? Bottom end issue? It has comp pro magnum rocker arms, comp pushrods, isky guide plates etc. etc.

347 tick - YouTube

Thank You,


Brian

PS - Next up is to start pulling plug wires and seeing if I can isolate the cylinder.

 

[Cobra4B]

ttt... anyone?

 

[vertvert]

I'm sure you checked this but how much oil pressure do you have at idle?

 

[Noobz347]

Go back and give each rocker arm a quarter turn. If the noise changes then you know where it's coming from. If it doesn't then you're going to be looking deeper into the motor.

My initial thought was maybe a roller-lifter not sitting right but that sounds like death and you'd know without doubt that something wasn't right. heh