Budd Davisson, Plane and Pilot, Jan 2003
Zen of the Overhaul

"Messing with an engine's Karma is never a good thing"

It couldn't be happening! I listened to our mechanic explaining what had to be done and felt the same heavy heart I'm certain always precedes major surgery. An organic being was going to be partially dissected. Balances upset. Forces set in motion, the results of which wouldn't be known until much later in life.

In my heart, I knew it would never been the same. My engine's karma was about to be disturbed.

At the very least, I would never been the same, even if the engine was. A portion of my peace of mind which I had fought so hard to develop would be compromised.

First recognize that though I may be a philosophical optimist, I'm a hard core mechanical pessimist. There's not a second when I'm strapped in the cockpit that I don't expect it to quit. When flying over ragged, sharp edged mountains, I visualize each white hot fire as it explodes, ramming the piston down, hammering the crank and twisting the propeller. It's a well oiled dance of destruction that can't possibly last forever. There are limits. It has a finite life. And I'm always worried about the exact definition of "finite."

Where will I be when "finite" arrives and what form will "finite" take? The non-answer keeps me on edge. Always seeking flat topography. Always keeping the parachute packing current.

The original engine in our airplane had never been a happy one. It was always sending out the occasional strange vibration. Changing it's exhaust tone. Leaking enough bodily fluids that the belly was usually a mess. It always kept us guessing.

I didn't trust that engine one damned second of the hundreds of hours I spent behind it. I was glad, actually relieved, when it finally decided to puke most of it's oil overboard, signaling it was time for an overhaul, whether we wanted it or not.

"Finite" had arrived in a benign fashion. The airplane was stranded at a cross town airport covered with oil, but whole. At least it didn't have a Saquaro molded around it's nose, its gear and lower wings wiped out by desert rocks.

This was our chance to do what was right! We went for what we considered the ultimate in mechanical peace of mind by going to someone who cared about the engine's state of mind as much as we did. I was so pleased knowing Jay Wickham and the Mattituck munchkins were now on our side. In my mind they are the best. What ever it cost, they were going to orchestrate my well being for the next 1400 hours, or so.

We cut no corners. We opted for what was basically an exchange engine using our heavy flange crank. New jugs. New cam. Low time case. We didn't mind spending many thousands of dollars extra because we'd make it back in TBO. More important than that. We'd make it back in peace of mind.

We finally had an engine we could trust.

Our joy increased as time built on the engine. As the various parts found harmony with one another, it became more powerful. And smoother. It continued to improve until it had the vibrational characteristics of an electric motor. We were loving it!

Every part had found peace with its neighbor. They sang and ran together as a family. The aura surrounding them was one of power, smoothness and trust.

Then the Service Bulletin arrived. My world was shaken.

It seems that every engine built and overhauled after a specific date may have an infection. Its wrist pins may not " up to Lycoming's usual high standards..." This, even though the pins were manufactured by the factory. Or by one of their anointed contractors.

The cure was intrusive and severe: since the identifying codes couldn't be found on the cylinders, all four had to be pulled. At 97 hours, we were violating the sanctity of what that time had built up.

We were disrupting the neighborhood.

I was not a happy camper. Okay, I'll freely admit that mechanical pieces are mechanical pieces. They are bolts and nuts. Cylinders and pistons. All parts carefully detailed on the blue prints and just as carefully manufactured. Putting them together is a simple exercise in reciprocating erector set assembly. No magic. No hocus pocus.
But something happens, after the engine begins running. With luck, the karma of the individual pieces mold around that of other pieces. They get to know one another, and, if lucky, they like one another. They rub against each other until they lap themselves into a smooth frenzy of togetherness.

It is the simpatico affinity of the parts for one another that define the personality and character of the engine. Ours was one of the good ones. A rare combination of internal combustion happiness that, if examined under a microscope, would defy understanding or description.

Scott, our mechanic, is also one of the good ones. But, he can't possibly get the jugs seated in such a way the individual parts don't know they've been disturbed. The induction system "O" rings, for instance, know they aren't where they've been laying for those 97 hours. The flanges don't sit exactly where they did when initially torqued down. Every part touched, knows it is no longer laying in the comfort zone it had made for itself.

Now, the parts will have to redefine their comfort zone. And the new zone will not coincide with that which existed before. Things will have changed. And I will know it. I will know it because my own comfort zone will need to be readjusted. This is a psychologically wearing process. It won't happen quickly because trust never comes easily.

In the past week or two, I've put about 20 hours on the airplane. I've been flying it hard. I've been listening even harder. Scott did a good job. The firewall is dry, it starts cleanly and it seems to pull like it always did. It gives no outward indication it was ever touched.

But, I can tell the difference. Its karma is just not the same.