Here at the magazine we routinely get questions about what makes more sense when it comes to engine overhauls. Specifically, should you commit to a field overhaul or stick with the factory? As it’s always been, there isn’t a one-size-fits-all answer, and there isn’t a hard standard when it comes to field overhauls. But there are some important things to consider, especially in an engine market disrupted by supply problems and in some cases, slipping quality.
OFFICIAL TERMS
Different terms can make for sizable price differences in your overhaul. In the engine world, you’ll see the words overhaul, rebuilt and remanufactured. The word remanufactured isn’t even an FAA-recognized maintenance term. But the word overhaul is, and it’s specifically defined in the regulations.
FAR 43.2 isn’t exclusive to engines, so you can reference it for other components, too, and it’s important for getting what you bargained for. It says, in part, that no person may describe in any required maintenance entry (or form) an aircraft, airframe, aircraft engine, propeller, appliance or component part as being overhauled unless using methods, techniques and practices acceptable to the Administrator, and it has been disassembled, cleaned, inspected, repaired as necessary and reassembled. There’s also a requirement for testing and proper documentation.
You’ll see shops use the term “overhauled to manufacturer’s new fits and tolerances,” rather than calling it a rebuilt engine. Take it one step further and ask the shop what it plans to do with your engine, and look for the proper language in the signoff.
WHAT MAKES SENSE?
For a relatively common engine with high time (and assuming the engine still operates) the factory has generally represented the best option since you’re likely to have non-serviceable parts that will need replacement, but that won’t affect your core credit. Consider that field overhaul quotes are based upon serviceable subassemblies, such as crankshafts, crankcases and other components.
A high-time, multi-run engine can cost far more from an overhauler because of an accumulation of upcharges for non-serviceable parts. Conversely, on a first-run engine, there’s a lower likelihood that major components will be worn beyond reusable limits, so your costs on a first-run engine should hover near the basic quotes that you get from a field shop and these will likely be lower than the factory numbers. On the other hand, these days with huge price increases, you’ll need to put a sharp pencil on the numbers. Look out for surprises.
As one example, if your crankshaft is scrap, the shop will charge extra for a new or serviceable crank, where the factory won’t (at least Lycoming) as long as your old engine arrives in operable condition for a core credit. Don’t expect to send an inoperable engine to the factory and get core credit. Got a known good crank and case? A field shop may be the better choice for an overhaul because you get to keep your low-time parts, not counting accessories, which you might want to be inspected and rebuilt, not exchanged. Sometimes, there are special circumstances. Some years ago, TCM wasn’t charging extra to provide a new VAR crank to IO-520 customers turning in a non-VAR crank. TCM wanted to get non-VAR cranks off the market and would pay to do it. But factory largesse comes and goes.
WHAT WILL YOU GET?
Having your first-run engine overhauled by a respected shop, you’ll have direct knowledge of just how old the components that make up the engine are and that’s a distinct advantage. A factory engine will probably have more new parts and definitely new cylinders. Field shops often quote three prices—one for overhauled cylinders, one for factory cylinders and one for aftermarket cylinders. On the upside, from a field shop, you can get any type of cylinder you want.
As another example, Lycoming historically had three engine categories: overhauled, in which parts meet factory in-house service limits; rebuilt, where the engine is given a new data plate and a zero-time logbook and all parts must meet new limits; and brand-new engines, with all new parts. Both Lycoming and Continental have service literature mandating certain parts be replaced 100 percent at overhaul. This list is long and not the same for both factories. For Lycoming, it can be found in SB 240T and for Continental in SB 97-6, both available on the company’s respective websites. The important point is that Part 145 shops will also replace these parts. Still, the reality is they only have to comply with ADs, not bulletins, but Part 145 shops also comply with any bulletins considered important.
CHOOSE CAREFULLY
Of course, where you have the work done (and the logistics that tag along with it—including freight) are just as important as knowing what you’ll get for your money. Our experience has often showed that engine distributors who are also engine shops may do a better job of after-purchase support.
As we’ve consistently found in our surveys, top engine shops got to be top shops not necessarily because they turn out better engines, but because they’ve built a loyal customer base through exceptional service and standup warranty performance. The key in shop selection, then, is reputation. Sure, price is a consideration, but not the only consideration. These days it’s easier than ever to get help finding a shop that knows how to support its work thanks to type clubs and social media. Although we caution that an advertising campaign in a type-club magazine is not necessarily an endorsement by the type club, unless it says so because, well, shops pay for ads. Direct recent experience of someone you know also counts heavily as a good referral. We recommend building a spreadsheet or a notebook with comparative quotes from at least three shops and, of course, the factory. And do this before you need to move on an overhaul because you’ll have far less pressure to make a decision. In other words, plan for the work in advance and be ready to pull the trigger when the time comes.
Understand, too, that shop information and performance isn’t static. Management, ownership, press, FAA sanctions, warranty policy, prices, what’s included in the overhaul, areas of expertise, waiting time and more all can change overnight. It’s the nature of business, especially small business and definitely the engine business. If a friend had great luck two years ago, check to see if ownership and management are unchanged. Reliable information has a short shelf life. We’ve heard nightmare stories from shops that once enjoyed stellar reputations but went downhill fast when the shop was sold or key personnel left.
Visiting the shop is a good idea. That’s another reason we favor using a shop nearby. But often, you just won’t have the time or opportunity. If you do visit, look for a dedicated engine assembly area (a clean room) and have the shop show you how they QC cylinders and other parts before installation. If the shop seems disorganized and out of sorts, it could be a red flag.
Ask the right questions. Get a copy of the written warranty and compare it to competing bids. Increasingly, there are differences in warranties. Does the shop comply with factory bulletins or just required ADs? What’s the deposit requirement, if any, and how long will the job take? These days, a snag in the supply chain can happen at any time and it could ground your aircraft for a lot longer than you bargained for. Ask the shop for a realistic estimate on downtime—and add a buffer to be safe. Don’t schedule important trips until you’ve retrieved the aircraft from the shop and have done lots of local flight testing.
Last, good shops are honest and can advise you when a factory engine will be a better decision. The good news is that there are a lot of high-quality field overhaulers across the country. We’re preparing an engine field overhaul satisfaction survey for a report in an upcoming issue of Aviation Consumer. Got an experience worth sharing? We want to hear about it.
