Michael Peters is an engine man, through and through. For the past few years, he ran a small repair station, KTM Engines, in Sparks, Maryland. A few months ago, Michael moved to a hangar at Frederick Airport and opened a shop called KTM Mid-Atlantic Engines. Michael doesn't just know aircraft engines; he is a machinist (as well as an expert marksman) and his work reflects his meticulous nature. He doesn't just put an engine together, but considers factors that ordinary engine overhaulers might overlook; it makes a big difference.

The first step, once I made the decision to overhaul my engine, was how to go about the overhaul. Thanks to Michael's suggestion that an overhaul was in order, I already planned to work with him on my engine, so trading the engine in for a factory overhaul didn't make much sense. Besides, I wanted to experience an overhaul from start to finish.

Once I was committed to tearing down my engine, it was a simple matter to finish removing it from my airplane. I had already removed two cylinders. With the help of my friend Chris, a highly talented high-end auto mechanic, we removed the remaining two cylinders, then disconnected the bottom end of the engine and loaded everything into my car for the trip to Michael's shop. Chris was amazed at the simple design of my Lycoming O-235, compared to the sophisticated engines that he works on.

Having made the decision to overhaul the engine, I had a secret hope that Michael would find something seriously wrong with it, to justify the thousands of dollars I was about to spend. After all, Lycoming said that the engine was way overdue for its overhaul (19 years overdue), so the chances were good that we'd find a problem.

The last two cylinders weren't in such bad shape, Michael said when he looked them over. We quickly disassembled the bottom end and split the crankcase halves with a neat tool Michael made. The tool pulls the crankcase half while pushing on the crankshaft to lever the halves apart. This avoids the use of a shim or other tool on the machined mating surfaces of the two halves, which invariably causes damage.

Disassembly was easy. All the steel parts went into a box to be shipped to the plating company or for inspection and rework. Lots of hardware that would be replaced was thrown away, and the rest of the parts were put on a cart to keep them separate from the other engines. Michael boxed up the crankshaft, camshaft, and crankcase and shipped them to various vendors for inspection and repair and I kept all the accessories so that I could have them overhauled.

My philosophy for the engine overhaul is to try to do as much work as possible to increase the chances of the engine making it through the next TBO cycle without big problems. This means paying attention not only to the engine, but everything under the cowl, including the engine mount, baffles, ducting, etc.

I sent the engine mount, which had some corrosion, to Kosola & Associates in Georgia, for the full overhaul treatment. The baffles were not doing the best job in the world; this engine always ran hot, so I sent them to BaffleBoy in Massachusetts, which is a service that Brooks Margolien provides at his shop at Minuteman Airport in Stowe, Massachusetts. Brooks replaces worn baffles, builds new and stronger parts where needed, and beefs up weak areas so the baffles will last longer.

The hardest part of the job was cleaning up the firewall, which is made of steel and had grown some rust spots. I removed all the gizzies attached to the firewall and cleaned off all the old zinc chromate primer and reprimed and painted it a soft gray.

It wasn't too long before Michael called with some news. "Bad news," he said. "Your crankshaft is no good. It's cracked." We had shipped the crankshaft, camshaft, connecting rods, tappets, and other steel parts to Rick Romans in Tulsa for inspection and rework. The Magnaflux inspection of the crankshaft revealed two large cracks on the rear main journal. The workorder from Rick Romans says it all: "REJECT for airworthiness."

At first Michael sounded puzzled when I thanked him for the news. I had to explain that I was happy that we had found the cracked crankshaft. He said that usually, he hates to call customers with bad news because they often get angry and sometimes even blame him for something that was wrong with their engine. While I was not happy about having to find a replacement crankshaft and the dollars this would add to the overhaul, I was glad that I wouldn't be flying around with an obviously defective major component. It was, in a way, a big relief. Not only had we found something seriously wrong, but we instantly justified the huge cost of the overhaul.

Next installment, finding a crankshaft.