Detonation Marks in Head. Ok to Rebuild?

[mike621]

I recently picked up a 885 head to rebuild and eventually swap onto my (running) car. I've started to clean up the cylinder head and noticed some marring in the bowl area adjacent to the valves. These marks are in 4 of 6 of the cylinders.






Could this be from detonation and do you think smoothing this out prior to resurfacing would be sufficient?

I plan to send the stripped heads to the machine shop after some cleaning and polishing.

I've rebuilt cylinder heads for Subarus before and from what I recall detonation marks were a little different.

Thanks in advance.

[Supratreo]

Looks like spark plug ground broke off in there or something. I'd say it can be reused but as cheap as these heads are I'd just get another one haha

[AndrewBird]

I'd try smoothing it out and see what happens. Worst case you have to get another head, which you are looking at right now.

[TobyB]

Those were chunks, not det.

For a street car, I'd nib off the high spots and call it "ok, but not ideal"

t

[digger]

yeah, sand the high spots off and move on

[mike621]

Thanks for the input. Used a rotary tool on low speed to knock down some of the high spots. Going to finish disassembling the head & continue polishing and cleaning soon.


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