A little history first

Bought a used Ofna LX Comp off craigslist a few months back - came ready to run with a Force 26 engine - since then I have run about 1.5 gallons of fuel through it keeping it on the rich side as I am just bashing the car around the neighborhood. She has been strong

Yesterday I lunched the engine while at full throttle - she sputtered then died. Let the car cool off while we played with the neighbors brushless conversion - came back to restart mine and she would not spin over. Pulled it off the chassis and it started pulling it down and started finding chunks of aluminum (small pebble side) behind the back cover. Surprisingly no obvious damage. Pulled the head and and found pieces of metal on top of the piston. Cleaned it all up and she would spin again. Probably has enough compression to fire. Thought I would pull the sleeve to try and figure out what let go.

So here is the real question - back when I flew planes a lot to pull a sleeve all I did was put a match stick in the exhaust port spin the prop by hand and the piston would push the sleeve out. From there you could disassemble the rest of the engine.

Tried that last night and all I was able to do was chop the match stick in half - tried a bamboo skewer same results.

Is there another technique for car engines?