Engine "clacking" when warm

[MrBurgundy]

So, I had refreshed my motor, new rings, rod bearings, valve job and some other things along the way.

The engine runs fine, but after it warms up, the engine develops this clacking noise which is rpm dependent. The noise becomes audible after 2.5k rpm and is the loudest on deceleration at high RPM

I took the engine apart again to inspect everything that was done and everything checks out.

Sounds like piston slap, but what makes me not think that's the case is the sound is present only when warm...

Any insight or experience with something like this?

[ForcedFirebird]

I had a car that did something like this. Turned out to be a loose rocker arm boss in the head. Slid the rocker shaft back, knurled the boss and slid it back. Far reach to be the problem you are having.

Can you get us a sound clip?

[MrBurgundy]

I had a car that did something like this. Turned out to be a loose rocker arm boss in the head. Slid the rocker shaft back, knurled the boss and slid it back. Far reach to be the problem you are having.

Can you get us a sound clip?

Yeah, I'll get a clip right now.

when you refer to the boss, are you just talking about the holes the shaft slides through or the actual shaft?

[MrBurgundy]

https://www.youtube.com/watch?v=ArP4ebsiTVg&feature=youtu.be&fbclid=IwAR2-dvnOL5sVHbpOvkxMAtgFP_B5_wyuKjQLzs5C4MS1dZF8f3kDo2uW3lI

Here's a vid of it.

[digger]

Seems like it is too high frequency to be valvetrain related.

Crank hitting crank scraper ?

[MrBurgundy]

Seems like it is too high frequency to be valvetrain related.

Crank hitting crank scraper ?

yeah, I was leaning towards that too..

Especially since the noise almost subsides under load and off throttle it get crazy, so I'm thinking it was yet another shit INA tensioner. Gonna pull the cover off today and replace the tensioner and the spring.

[MrBurgundy]

Tensioner didn't help, the guy who did my head is coming over to hear it..

[ForcedFirebird]

I replied on my phone, must have never hit "post reply".

Definitely sounds like valve train noise to me. I have often run the engine with the valve cover off to pinpoint issues like that. Just plug the crank case vent tube, and might want to put down something to collect the oil spatter.

Some of the common issues:

Loose rocker retainer
Eccentric installed backwards
Loose cam gear
Loose tolerance on rocker shaft to head boss
Rocker bushing out of tolerance (rockers "rocking" lol)

[MrBurgundy]

I replied on my phone, must have never hit "post reply".

Definitely sounds like valve train noise to me. I have often run the engine with the valve cover off to pinpoint issues like that. Just plug the crank case vent tube, and might want to put down something to collect the oil spatter.

Some of the common issues:

Loose rocker retainer
Eccentric installed backwards
Loose cam gear
Loose tolerance on rocker shaft to head boss
Rocker bushing out of tolerance (rockers "rocking" lol)

So I isolated the noise to the exhaust rocker.

when I put the stethoscope on it, it's ticking ever time a rocker depresses and comes off the valve.

Pretty sure you're right forced, the shaft isn't sitting tight enough in the head.. I might just put a set screw in it.....