Overhaul Shopping: If It Were My Engine …

This article appeared in the April, 2002 edition of Aviation Consumer and is reprinted here by permission.

Any aircraft owner who expects the experience to be one slam dunk after another can be certain of only one thing: disappointment. Nothing about owning an airplane is a sure thing, least of all maintenance decisions.And topping the list of less-than-surefire things upon which to spend money is an engine overhaul. It's the single most expensive sooner-or-later decision any owner has to make and the outcome seems, at best, to be a shot in the dark.We suspect that this leads more than one owner to wish for a brother-in-law in the engine business, someone who could cut through the smoke and mirrors of marketing claptrap and the shadowy claims and counterclaims that don't appear on the overhaul invoice.With that in mind, we recently approached the principals in four top engine shops and asked them this simple question: If your brother-in-law came to you asking for a good steer on an engine overhaul, what would you tell him? Or put another way, if it were your engine being overhauled, what would you insist on making sure the shop did or did not provide with your new engine?This concept drew some interesting reactions we can best characterize as beginning with a long pause, followed by a thoughtful silence and another question: "Is this on the record?"Yes, we replied, it is. Time to come clean with the true inside stuff free of potshots at the competition, marketing fluff and mealy-mouthed maybes.

We picked four shops, three on the east coast, one on the west coast. Our criteria? Our assessment of shop reputation. For many years, Aviation Consumer has conducted surveys of its readers asking them about engine overhauls. We've never found our guys shy about roasting an engine shop that delivers a clunker or fails to perform on warranty support.Right up front, every reputable shop in the business will tell you that they occasionally turn out a bad engine. Either the parts weren't up to snuff, somebody screwed up during assembly, the installer goofed or all three. But if that engine came out of a good shop -- at least one that meets our criteria for "good" -- we rarely hear about it because the shop does the right thing with a no-questions warranty or, if the engine is out of warranty, a little help that the customer considers fair.These four shops meet those criteria and then some: Teledyne Mattituck Services in Mattituck, N.Y.; Penn Yan Aero in Penn Yan, N.Y.; Zephyr Aircraft Engines in Zephyrhills, Fla.; and LyCon Aircraft Engines in Visalia, Calif.Based on our surveys, we've heard nothing but positive comments on these shops and, as near as we can tell, not a single complaint. We're not naive enough to believe no one has ever had a beef with any of these overhaulers, but we stand by our observation that all are exceptionally good shops.

Along with Mattituck, Penn Yan Aero is one of a handful of shops whose history dates back to the 1940s. It was established in 1945 by William Middlebrook as a general repair facility that evolved into an engine shop during the 1960s. William -- known as "Eagle" -- handed the shop to his son Daryl. Today, the founder's grandson, William Middlebrook, oversees the overhaul business.In addition to overhauls, Penn Yan has established itself as a cylinder overhaul facility, a business that has diminished somewhat due to the decline in new cylinder prices. Still, Penn Yan is noted for its excellent cylinder work.Not too surprisingly, before getting into the nitty gritty of what he would want in an overhaul, Bill Middlebrook mentioned what we've heard mentioned so many times before: warranty. What's the shop's warranty and what's its reputation for performing? The industry standard is six months and 240 hours, plus a pro-rate."To me, that seems miniscule," Middlebrook told us. "We went to two years and 500 hours. What we discovered was that when a customer with a two-year-old engine was calling with a problem, we were taking care of him. So why not publicize it?"Fair enough. But what about the overhaul itself? We asked Middlebrook for his short list of must-have requirements. At the top, says Middlebrook, is a new limits not a service limits overhaul, a requirement we heard stated over and over again. We're not sure how many shops still sell service limits overhauls in the current market, but we're sure some do. Service limits overhauls were once the norm; they aren't now.Next, says Middlebrook, ask the shop to specify which parts will be replaced as new -- both Lycoming and Continental have an approved list -- and whether ADs and SBs are complied with as part of the overhaul price. Surprisingly, AD compliance, whether requiring parts or not, is sometimes an upcharge on the invoice. Ask about it going into the deal, says Middlebrook.When engine shopping, Middlebrook says he would get a written list of what's proposed in the way of parts and processes and at what prices. Some shops will have more detailed lists of this than others, but it's often the only way to compare the real value of the overhaul, apart from warranty performance."Some shops charge for repair on a crankcase, some don't. You want to know that ahead of time because it can be the difference between a $12,000 invoice and a $20,000 invoice," he adds.Middlebrook says he would also ask about the shop's policy on crankshafts and camshafts. Again, new limits only here, not service limits. Obviously, cranks are routinely reused but cams may or may not be. A reground cam isn't out of the question but a new one may be more cost-effective, especially in a Lycoming. Middlebrook tells us he would go either way, depending on condition.Given the price of new cylinders, are fresh jugs an automatic no-brainer? "Not necessarily," says Middlebrook. "I think it's engine specific. In something like a Navajo, I'm going to recommend new cylinders because of the downtime issue. It's a working airplane and if it needs a top overhaul, the downtime is going to cost more than the difference between new and overhauled cylinders."But for a less-stressed engine, say Lycoming's O-320 series, Middlebrook says an overhauled first-run cylinder may be the best value.Other items on Middlebrook's checklist: A detailed listing of what warranty items are covered and what aren't. Are parts, labor and shipping covered? Which accessory items are new and which aren't? How is the engine tested and is that test data given to the customer?

Most well-known independent overhaul shops purposefully keep their distance from, and in fact compete with, the two major factories. A recent exception to this rule is Teledyne Mattituck Services, another blueblood shop with roots extending back to the 1940s.It was founded in 1946 by J. Parker Wickham and is today operated by the founder's son, Jay Wickham. In 1999, the Wickham family sold the business to Teledyne Continental Motors and Teledyne-Mattituck Services operates as a division of the TCM factory in Mobile. Interestingly, that means it competes with both its parent organization and provides overhauls on engines from the other side of the tracks. Only in general aviation ...Mattituck has a reputation for working with customers beyond the confines of its stated warranty, a policy that has earned it almost fanatic loyalty and return business.Jay Wickham told us the first question he would ask of a shop doing his brother-in-law's engine is this: What am I getting back?"The hardest thing for owners to understand when specing an overhaul is how important it is to know what you get back on your engine. Do you get your crankcase, your crank? What else?"Wickham reasons that any shop doing new limits overhauls -- and most do -- will follow Lycoming and Continental recommendations on new parts so, in that sense, overhauls may be broadly similar. But absent any specific understanding to the contrary, it's quite possible that you could wind up with a replacement case or crank from the pool, depending on what cores the shop has around or what cores it would like to have."If I had a good crank and case going into the shop and I know the history of it, I'm comfortable with it. I want that stuff back and I'll ask about it," says Wickham.But Wickham differs with Middlebrook on cylinder choices and he'll steer his brother-in-law toward new ones. "When an engine comes back to us, very seldom is it a problem with major rotating parts. It's usually cylinders," says Wickham."My choice is going to be new cylinders. New is new. I don't like cylinders with three sets of serial numbers and several runs. I just wouldn't mess with it."But wait a minute: Like Penn Yan, Mattituck overhauls and sells used cylinders. Yes, says Wickham, it does, because some customers prefer overhauled cylinders as a means of saving money. The shop would be remiss in not offering them. "We will put on whatever the customer wants," Wickham says.How about other new parts? "We don't put any engine together without a reground or new cam. And I'd rather put in new than reground," says Wickham. "From an engine builder's point of view, if a cam fails, you have to have that engine out of the airplane and we want to avoid that. We can't control how you lean, how often you change the oil and whether you pre-heat, but we can control which major parts are new. It's cheap insurance."Teledyne Mattituck offers the standard 6/240 warranty, with pro-rate. But everyone and his brother knows the real warranty is some hard-to-define period that's longer than that. Sometimes a lot longer. In fact, a TCM factory rebuild sold through Mattituck -- it is, after all, a distributor -- will enjoy the same informal extended warranty support that one of its field-overhauled engines does. Wickham declines to say as much, but readers impressed with Mattituck are more forthcoming.Which leads to the three things Wickham considers most important in selecting an overhaul: proven reputation on warranty performance, a confirmed written list of new parts and confirmation of returned core parts and, last, an engine-testing procedure with specific procedures outlined and test data provided to the customer.

The Mattitucks and Penn Yans of the world make their bread and butter on hundreds of engines sold into the national markets but a handful of smaller shops do fewer engines and enjoy just as good a reputation with customer loyalty to match. Some ply the regional market, others local, regional and national. Zephyr Engines is one such shop, turning out a dozen engines a month.The shop had been around in various incarnations since the mid-1960s but was bought by Charlie Melot in 1992. Melot did stints at other well-known engine builders, including Mattituck and G&N.Like the other shops we contacted, Melot says the assumption is a new limits overhaul, not a service limits overhaul. Whether that's understood as a given may not necessarily be clear in either the buyer's mind or the shop's sales pitch.As did Penn Yan's Middlebrook, Melot thinks it ought to be stated clearly up front. Further, the list of replacement parts should be stated, either on the bid or on the invoice and the customer should expect to get a copy."I don't know how often it happens, but we see some engines from other shops that look like they were built with floor sweepings," Melot says. "I'm big on accountability. I want to know what parts went into that engine. What rod bolts do I have? Where did the crank come from?"We know from experience that some shops are better at documenting and logging than others but if two shops are building roughly the equivalent engine, Melot says he leans toward the better-documented job. In the event of a recall -- hardly unusual these days -- a detailed invoice could save the owner the headache of massive downtime and an expensive exploratory teardown only to find that an AD didn't apply after all. Further, such documentation will indicate that service instructions were followed and all ADs were taken care of.Melot leans toward recommending new cylinders, especially on smaller displacement engines where the cost delta between new and used is not especially great. First-run cylinders are candidates for re-use, in his view, but he adds, "If I get any engine in here and I don't know where the cylinders came from, I'm going to want new cylinders on it." And on any engine where the cost of new cylinders is within 10 to 12 percent of overhauled, Melot says new ones are a no-brainer. Things he would keep an eye on and ask about: casework, approved processes for cams and cranks and replacement of major gears. The art of sealing a crankcase, says Melot, seems to be beyond the capability of some shops and he sees cases poorly sealed and fitted, with so much fretting as to render them junk. Major gears -- cam, crank and accessory drive gears -- are expensive and the temptation to reuse marginal ones is great. Ask the shop about the gears and look for documentation on the invoice.

"I guess what you're after is a consumer checklist for overhauls," replied Ken Tunnell, of Lycon Aircraft Engines, when we called for his take on advice he'd give his brother-in-law on an overhaul.LyCon has been in the business for more than 20 years, having been established by Tunnell, his father and his younger brother Bryan. The business specialized in agriculture work initially, a market that's big in California's Central Valley, where Visalia is located.Today, LyCon is well-established as an overhauler of conventional flat aircraft engines, rather than the radials it started out doing.Like Mattituck's Wickham, Tunnell has a short list of important items he wants to see in an overhaul. At the top is a good crankcase, with clean and flat mating surfaces and main and lifter bores in good shape. Even the best cases, he said, might have elongated crankshaft bores that should be corrected with line boring. Not all shops do that, however. Better ones do it in-house or farm it out.It's all but a given these days that a crankshaft will be reused, but to avoid the need for a mid-run case split, Tunnell says he would want one near the top of the new limits allowance, not approaching service limits. (We often wonder how many shops cross this line on the crank, something a customer wouldn't necessarily know about unless trouble emerged during the run to TBO.)How about new cylinders? Tunnell says that about 80 percent of the engines that leave his shop have new cylinders, mostly as a reflection of good prices on new jugs. But he doesn't necessarily think new cylinders are always the best choice."A lot of what comes in here are full of cracks and are just junk. If the customer insists, we'll overhaul the one that can be overhauled. Otherwise, new cylinders are the way to go. But if the cylinders are off a short run and in good shape, new is a waste of money."Like the other shops, Tunnel believes the final acid test is not the engine itself but the shop that stands behind it. Warranty may not be everything but it's close. LyCon's current warranty is one year and 300 hours, with a pro-rate at 30 hours per month to TBO. We suspect that like other shops, Lycon nudges actual performance beyond those numbers.