My engine is a little different from some of the hotrods other forum members have built.  I raised my compression by machining about .130” off the top of my cylinder instead of installing a pop-top piston (Wiseco).  I used the stock flat-top cast piston and machined four valve reliefs in the piston.  My intent was to provide a good tight quench area between the cylinder head and the piston.  It worked too good.  It had whopper compression and the cranking pressure was too high (245 psi).  I was able to mitigate that problem by installing a Web 340b grind cam, retarded 5°.  It seemed to be working fine on pump gasoline (92 octane E10).  I put several thousand miles on it that included hundreds of full-power pulls and some dyno pulls.  All sorts of torture.

There were tests on the camshafts, tests on the breather system, tests on air filters, tests on carburetors.  All the tests involved full power ops to the max.  It was spending way too much time at engine speeds well above what any normal person would consider reasonable.

In the middle of all that testing, I sucked in a cylinder base gasket, so I had to tear it down.  At that time, the piston assembly looked great.  Not a hint of trouble.

Fast-forward about 1000 miles to Super Bowl Sunday.  I end up with this after getting a little lazy and anxious.  I should have waited until I had that WOT mixture deep into the 12 zone before trying to set the land speed record (LSR).  Good lesson for this old dog.  I think you will find these photos interesting, and I am also hoping I can pry some good comments and advice from the experts on this forum.

You can see from the first picture in this post that a section of the piston top is missing.  The section extends from the left-hand intake valve relief to just a little past the middle of the piston.  The photo below shows the piston from the side, note how the top of the piston appears to be pulled up.

And of course, the intake side is a mess.  Why the intake side?  I thought that side would run cooler.

I’m happy to report that a few quick passes with a ball-hone cleaned it right up.  It’s only .0001” over design specs, and still .0009” below the wear limit.

I was wondering where that chunk of piston top went.  As I was cleaning up the combustion chamber, I figured that out.  The combustion chamber had a nice layer of aluminum flame-sprayed all over, especially the intake side quench area.

It flame-sprayed the exhaust valves.  Cool (or should I say hot, as in JetHot?).

After I cleaned up the valves with scotchbrite and oil, there was still aluminum forge-welded to the seating surface.  I will probably have to replace the exhaust valves.  I think the intake valves can be cleaned up with a Neway Gizmatic.