Detonation, pistons, and valves.
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Staging Lane
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Detonation, pistons, and valves.
I have a heads/cam stock bottom end LS1 motor that was run on a mail order tune too long. I took the car up to have a tune done and it was down about 100hp on power. When the engine was scoped by the shop on the #5 and #7 pistons they said the faces look like they've seen detonation but the edges of the piston and cylinder walls look brand new. No compression/leak down tests were done. The plugs showed white peppery residue consistent with detonation.
Which leads me into the following question: if the edges of the piston look fine through the scope, is it most likely the low numbers are a result of the valves being burnt? If I pull the heads and clean off the piston faces and there isn't any pitting/cracks/etc is alright to continue to use the short block and just have the valves replaced in the heads?
The engine isn't burning any oil which leads me to believe that there isn't any significant damage to the pistons, but I don't have a ton of experience diagnosing this problem.
Which leads me into the following question: if the edges of the piston look fine through the scope, is it most likely the low numbers are a result of the valves being burnt? If I pull the heads and clean off the piston faces and there isn't any pitting/cracks/etc is alright to continue to use the short block and just have the valves replaced in the heads?
The engine isn't burning any oil which leads me to believe that there isn't any significant damage to the pistons, but I don't have a ton of experience diagnosing this problem.
#4