Ron M., an experienced Aircraft Maintenance Engineer (Canadian equivalent of the US A&P) agreed to help me pull two cylinders to check for any internal engine corrosion. The engine was “preserved” by Aerosport Power immediately following the overhaul and test cell run, but that was seven years ago. If there was a problem, it would be cheaper and safer to find it now than deal with the consequences later.

I took a day of comp time today, and finished pulling off all stuff around cylinders #2 and #4. The Lycoming Overhaul Manual said to put the piston of interest at top dead centre, to allow you to grab the piston as you pull the cylinder off, to avoid it falling and hitting the crank case. I pulled the plastic plugs out of the bottom spark plug holes on those two cylinders, in case there was any oil in them - no oil. I assumed that the other two cylinders would be similarly oil-free, so didn’t bother to check them. I pulled the desiccant plugs out of cylinders 1 and 3, then started slowly rotating the prop to bring cylinder 2 to top dead centre. As cylinder #1 was coming up towards top dead centre there was suddenly a huge jet of oil that squirted out of the top spark plug hole. It went about 15 ft out into the hangar, making a mess over all kinds of stuff. A few drops sprayed in my hair, but fortunately none got in my eyes. What a mess. Lesson learned - beware assumptions.

Fortunately Ron wasn’t yet at the hangar when the oil disaster happened - he would have died laughing.

Ron pulled cylinder #2 off, and we had a careful look at the cam, crank and cylinder. Everything looked absolutely perfect. Not a speck of corrosion. Based on the good state of everything, we decided to not pull #4. I helped Ron get the cylinder back on, then he left. I had been on pins and needles, waiting to see how this inspection went. I was so relieved to find the engine in such good shape. Now that I have allowed a bunch of moist air into the crankcase, I want to get the first engine run done ASAP, so splash some oil on the cam and crank. I will try to get that done this weekend.

I spent the afternoon starting to reassemble induction tubes, exhaust pipes, EGT probes, baffles, oil cooler support, etc. I didn’t get it all done, but I eventually stopped so I could come home and have a celebratory bottle of wine.

Now that I know that I won’t have to delay the first flight while the engine gets opened up, I have arranged to do some tail wheel refresher training, possibly starting this weekend. I learned to fly on a tailwheel aircraft, way too many years ago, but I have done very little tailwheel time since, and none at all since 2001. I am going to fly with Andrew B., in his Maule and Pitts.