I was in Toulouse, France for the last week, on a course. It was good to be back in France again, but it meant no progress was made on the aircraft.

I took today off, and met with Andrew B. at the hangar this morning. He has removed and installed numerous cylinders before, and had offered to help me replace mine. It took us three hours, but we got the old one off and the new one on before lunch. Thanks Andrew!

I was surprised to see how much deposits had built up on top of the piston in only 95 hours, but Andrew said that it looked very clean compared to other pistons he has seen.

There was also a hint of scuffing on the piston skirt. Andrew recommends I keep the rpm below 1000 rpm for the first minute or two after start, as the aluminum piston heats more quickly than the steel cylinders. Combine that with the higher thermal expansion of aluminum, and you have a recipe for scuffing. Lower rpm for the first few minutes should put less heat into the pistons, and give the cylinders some time to warm up.

This afternoon I got a good way through reinstalling all the stuff I had removed to provide access to the cylinder. I got through the worst part of that, but still have several more hours to work to do before I can run the engine for a leak check. I'll do a very short leak check then do a two hour break-in flight. Maybe this weekend.