My TSIO-550E has been disassembled for months. The story is too long, but this issue with the piston stamps is interesting. About 1.5 years ago when the factory replaced all the cylinders and pistons the first SB had come out about No Stamp Marks on the top of the pistons. That was caught and I had pistons with the stamp on the bottom. This time I was waiting for all the new engine part because of a disintegrated Lifter and while we were waiting we took a set of new pistons off the shelf and sent them to the Coater for Ceramic coating the tops and Polymer coating of the skirts. When they were reassembling the engine a few days ago the new SBA was out and sounded like they wouldn't allow any stamps. The engine guy called TCM for clarification since my pistons had stamps on the bottom wrist pin bosses. He also just completed another TSIO engine and was running it in the test cell. TCM checked with there lawyers and said that he could not use the pistons that we had coated and had to use new ones without any stamps. So we sent another set in for coating. Also, TCM told him to replace the pistons in the running engine and they would pay his labor.

My engine has now 2 hrs of cell run time and is to be installed in the airplane this week, I hope?

As another note, my engine progress was held up for several weeks waiting the outcome of discussions over whether to put out a SB or AD on the Lifter issue. I was made aware of at least 5 other engines that had the same lifter disintegration problem.

Continuing Engine Saga,