Super Jet So what exactly causes Pitting?

[BrightE's]

I've had a lingering question on the back of my mind for a few weeks since looking more into aftermarket high-compression heads. Question is - what in the hell causes pitting in engines? Is it small bits of material breaking from elsewhere in the engine and somehow entering the combustion chamber? Is it from large particulate in the air that makes its way through the flame arrestor and into the engine?

And furthermore, what further damage can it cause? ie, why are used ADA domes with pitting less valuable than a new set, less be they have the same function?

 

[LimitedSlip7]

Detonation usually...

 

[BrightE's]

So it is simply just the combustion that causes the wear?

 

[kevbo]

I've had a lingering question on the back of my mind for a few weeks since looking more into aftermarket high-compression heads. Question is - what in the hell causes pitting in engines? Is it small bits of material breaking from elsewhere in the engine and somehow entering the combustion chamber? Is it from large particulate in the air that makes its way through the flame arrestor and into the engine?

And furthermore, what further damage can it cause? ie, why are used ADA domes with pitting less valuable than a new set, less be they have the same function?

Large pits on the combustion chamber normally means something came apart internally. Detonation by itself will leave a sandblasted appearance with more damage on the piston than on the head. Considering how much compression and timing people are running with pump gas, detonation probably caused the mechanical failure. Typical damage from smaller debris is to the cylinder, piston, and head. Larger chunks like broken pistons can punch a hole in the case as well. Comparing a new dome to one with damage is like comparing a new car to a wrecked one than still drives.