In the four years since our last survey (May 2004 Aviation Consumer), several things have changed in the world of engine overhauls. Teledyne Continental Motors (TCM) and Textron-Lycoming have both pumped up their marketing of zero-timed and factory-overhauled engines. Engine and cylinder rebuilders have expanded their presence with both Engine Components, Inc. (ECI) and Superior Air Parts offering complete engines to the experimental market. Superior is even certifying their Vantage engine to compete with the Lycoming O-360 and IO-360.

For all thats changed, however, the long-term viability of your new engine will largely depend on the quality of your cylinders. Is it a better road to use aftermarket cylinders like Superior Millenniums or ECI Titans? Or is it a safer bet to go with the OEM product?

We asked our readers for their experiences with new cylinders bought from Lycoming, TCM, ECI and Superior, as we’ll as with overhauled cylinders. (We didnt distinguish between overhauls done in the field vs. factory-overhauled units). Specifically, we asked questions like whether the cylinders made it to TBO, what early problems cropped up, how the manufacturer was on customer support and if the owner would use the same cylinders again. We also followed up with shops, the companies, and some individual owners to ferret out some specific issues with individual brands.

Promising Trends

Since our last look at cylinders, quality and customer service seem to be improving. don’t get too excited by that statement, however,

because the 2004 range was “mediocre to dismal.” Today its crawled all the way up to “pretty good to disappointing.”

Across the board, owners reported back that cylinders only made it an average of 528 hours before they needed work or replacement. While some respondents reported 1700 hours or more with no problems, they were the exception, and usually were at flight school or Part 135 operations where engines were flown hard and frequently. This reinforces the time-honored thinking that cylinders do we’ll when used regularly.

Customer service is part of the equation, too. We didnt get enough comments one way or the other to say anything about Lycoming support. But considering the survey is an open opportunity for someone looking for a place to vent-and several respondents did just that-no comments about customer support from Lycoming is telling. Respondents rated their customer satisfaction on a scale from one to 10, with 10 being best. The averages were all between 3.9 and 5.6, so we cant say anything with real authority here.

The bottom-line question, however, is “Would you buy this cylinder again?” Here Lycoming was the walk-away winner scoring 85-percent yes. Superior and ECI did well, with about a two-thirds retention. TCM took up the rear with a 55-percent yes. Thats worse that the 61-percent who would buy overhauled cylinders again, but an improvement over four years ago when two out of three TCM customers said they wont purchase TCM cylinders again.

Lycoming Leads the Pack

LLycoming has suffered near disastrous and expensive quality control issues with its crankshafts since our last survey, but its cylinder quality seems to be exceptional..

Stiff competition in the aftermarket has gotten Lycoming to drop their prices on cylinders when aftermarket cylinders (also known as PMA, or Parts Manufacturing Authority, cylinders) are available. This has created a two-tier system for Lycoming engine owners. When the engine is common, such as many of the parallel-valve IO-360s, there are at least four options: Factory-new from Lycoming, PMA cylinders from ECI or Superior, or overhauls. Any of the first three will run you around $1000 a jug. The overhaul may be only $100-150 less. Given the potential for longer field life of new cylinders, owners and shops simply arent bothering with overhauled cylinders on these engines and many are happy with Lycomings product. In the words of Alex Courtney of Penn Yann Aero, “We see about a 50-50 split between OEM and aftermarket cylinders … but the Lycoming nitrided barrels just work.”

Its a different story for angle-valve IO-360s where its either factory-new or overhaul. The price delta can be over $800 per cylinder. Based on comments from our surveys and talking to shops, few owners are opting for overhauled cylinders We suspect this may be skewing the results of how many Lycoming owners used factory new and would do so again. They simply see no other choice.

We didnt see any areas that seemed particularly prone to failures, nor did we see any differences between quality in the past and currently. We did hear a few stories of parts that stood the test of time. The owner of a Piper Lance with a Lycoming IO-540 told us, “New Lycoming cylinders installed in 1983 made 2065 hours with the lowest compression at TBO being 74/80. There is no logbook entry indicating that the cylinders were ever removed from the engine for any reason. The same cylinders were overhauled and returned to service.”

Continental Improves

Owner complaints with TCM cylinders fell into a pattern: low compression, valve guide wear and exhaust valves burning. As one IO-550-powered Cessna 185 owner put it, “This is my third engine