A pleasing engine surprise...
It has not been possible for me to fly any of my planes since last July, sad, but a reality. Two would be impossible to safely lend out (tricky checkout required), and there's just no incentive to lend out my 150. So they have all just sat for that period. I feel guilty letting equipment of any kind sit, but there was no attractive choice. So, knowing they would sit, I ran them all up, and taxied them around in December, followed by an oil change, and another quick run up. One in the hangar, and two bundled up as much as possible outside for a long and unkind winter.
It's now annual inspection time, and my daughter bought as a birthday gift a really nice, compact wifi endoscope/borescope - one of those Facebook recommended posts. It works wonderfully with my Ipad. What it showed me, when passed into each spark plug hole in my O-200, is not a spot of cylinder rust! Basic steel cylinders with about 800 hours, and the honing marks are as good as new! So now I have confidence that the rest of that, and the other two engines, may not be as bad as I feared.
I once picked up a friend's 150 which had been sitting for nearly a year. I took a charged battery, and gave it a very thorough walk around. When I pulled the prop through, I could hear the piston rings scraping rust in the cylinder walls. The plane had to be moved, so I fired it up. It ran, but was not eager. As it ran, and presumably broke in the cylinders again, it ran well enough to take off. But that was my lesson in try to not leave your engine idle for an extended time.
So I'm hopeful that my two Lycomings are as content as my Continental with a too long period of inactivity. I'm confident that the fresh oil run in December made a difference!