Curt
The failure was very weird. A piece of the piston, about 3/4 inch, came out just above the ring on the exhaust port side. It looked like it was cut out. The top of the dome had excellent color so it wasn’t running lean. There was no damage at all, not a scratch in the cylinder, port or head. It was like a chuck just dissapeared! I showed it to several moto engine builders and they all said it was really weird, never seen anything like it. Just my luck!
Tech was good and thorough. Don was ready to head for the bottom end as the other guy’s motor seemed to be just a bit too good. Head volumn is supposed to be 11cc. The other engine’s head was covered in oil after only 9cc went in! A little undersize. (Our’s was well over the 11cc limit.)
I’m making tools to check head profile and port height. Once made, a builder won’t be able to touch any of the surfaces without getting caught. We already have orders from all over asking for them. We had the prototypes in Florida, ready to go if needed. For Moroso, we’ll have the finished ones.