Hey guys taking apart a junkyard lq9 and I noticed some of my valves especially the exhaust valve tips have some pretty bad damage. Anyone know what would cause this? The valve guides actually seem really good. I haven't torn into the short block yet but will soon.

 

Lack of oiling or super high spring rates or both would be the first things I'd think of. I'd think about geometry too but with how the rockers are bolted down on an LS that seems less likely.

 

Damnit my assumption was a oil pressure problem as well. I guess I'll find out when I check out the main and rod bearings.

 

Lack of oiling, or possibly a super high lift cam that was scrubbing the rockers across the valve tip would be my guess

 

I haven't thought it could have an aftermarket can already I'll def have to check that out. Thanks for the idea.

 

I've pulled apart a couple that showed similar wear on the end of the pushrod and the rocker pocket, check that area as well. I attributed it to an oil issue. Junkyard/used motors, not every one cares for their LS like the rest of us.

 

Excessive RPMs with inadequate valve springs.

 

Sorry for the stupid question this is my first LS engine im familiar with first gen sbc engines. What do you mean by the rocker pocket? Is that the area the rocker arm physically sits and pivots on?

 

The pushrod cup in the rocker.
My L33 had several bad. The engine was very brown inside. Poorly maintained.
Bearings were fine though.

 

im really hoping to not have to do a full rebuild but my hopes aren't to high anymore.

 

Did you clean it up or just leave it as it was. My engine is super brown inside as well.