As Larry sez... I am not a fan of flying behind an engine until it has been torn down and inspected. I learned the hard way that what's in the logs isn't necessarily the whole story; and in some cases, isn't even related to what's actually in the engine. 25 years ago I had a used engine with 200 hrs SMOH in the logs blow up... at night... in the mountains. The remains of the engine made just enough power to extend the glide and I made it into an airport with about 100' of altitude to spare. Upon tear down, the only thing in that engine that had been overhauled was the log book. The part that failed had been superseded by service bulletin in 1947. The valves in that engine had been superseded in 1953. Oh yeah, and the mechanic that signed the logs for the overhaul apparently performed the overhaul 10 years after his death! That motivated me to get my A&P and I have built every engine I've flown behind since.
When I was building my SuperCub I did a log book review for someone that was interested in an O-320 Lycoming. Man, that engine looked really good on paper, and I recommended it as a good buy. I also told him that it looked so good that if he didn't want it, I would buy it for my SuperCub project. He passed on the engine, so I bought it. Even though it was a first run engine and wasn't run out, I wanted to go through it. I found; 4 badly overheated and cracked cylinders, 2 spauled cam followers and a spauled camshaft, a cracked crank, one wrist pin from an O-235 and a cracked and out of spec case. About the only thing good in the engine was the gears in the accessory case. It wasn't a cheap overhaul, but I am so glad I followed my first rule of aircraft engines; Tear it down and inspect it before you fly! ? -Jeff Scott +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ You might want to bump that up to $4000 and $4500 if you overhaul the carb, new exhaust and new mags. Less if you can find and engine in good condition that is simply bolted on , new exhaust, and run for hundreds of hours. Continental should cost less to rebuild as cylinders are hundreds of dollars cheaper. Any used engine should have the crank checked for run out indicating a possible prop strike. A lesson I learned the hard way. Jeff Scott would not recommend flying behind a used engine without disassembly and proper checkout. Good advise. In the end its a personal decision on your comfort level concerning reliability, and how much ongoing maintenance / rebuilding you want to be doing. I purchased an 0-200 with 1800 hours time, installed new mags and wire harness, rebuilt the carb, and put another 550 hours on it having only to replace one cylinder. I've since installed stainless steel exhaust and overhauled the mags and carb at the 500 hour mark. As always, your results may vary................. Larry Flesner
