The last couple of years development in aircraft engines has been more or less concentrating on diesel engines. We have seen one off installations to fully developed engine production lines. A number of companies are active on this market primarily due to major concern of long term availability and the relative high price of AVgas (Europe). JET fuel (avtur) is worldwide available and can be used in diesel engines. This fuel can also be made of renewable sources (biomass) which contribute to a cleaner environment.

But as there are lots of Avgas engines still being produced and consequently used and installed by kit aircraft builders, we spend some time with Lycoming and Continental type of aircraft engines.

And as perfectly said by Lycoming: Some engines purr like kittens. These roar!

Avgas Aircraft Engines

A number of engine manufacturers are still producing engines running on Avgas. Lycoming, Continental are the most common names. There are also a number of companies producing Lycoming look-a-like engines: Superior, Mattituck. These firms took the original design and improved upon that. They use technologies known in automotive engines for years as: multipoint FADEC controlled fuel injection, roller tappets, different, stronger and corrosion resistant alloys and such.

Initially these engines were developed for the experimental aircraft market. Testing new developments was (and still is) relatively easy and flight time and experience in these 'new' designs could be build quite rapidly. At long last we see these improvements in technology being incorporated in the certified engines too.

Roller Tappets in Action A good example is: roller tappets eliminate the sliding friction between the cam and valve tappet by incorporating a ball bearing in the tappet to reduce friction and increase durability.

In comparison, these engines are slow turning (max 2700 RPM), big bore pistons, are direct drive engines with high torque. Where as others run higher revolutions (4000-6000 RPM) to create power and must use a gearbox to drive the propeller and regain torque from revolutions.

Lycoming Textron

Lycoming, a Textron Company located in Williamsport, PA has been producing aircraft engines since 1929 when they build a 9-cylinder radial R-680. Some 25,000 of these beautiful engines were built and used in Stinson to Stearman aircraft, some of these engines are still flying. Although the company started out with automotive engines.

These engines are sold in four, six and eight cylinders versions with or without fuel injection, turbo and geared types (for the left truning types). The four cylinder versions are 235, 320, 360 and 390 cubic inch, with a power output range of 118 to 210 bhp. The six cylinder versions are 540 and 580 cubic inch with power output ranges from 235 to 350 bhp (540) and 315 bhp for the 580, and the eight cylinder is 720 cu.in with 400 bhp. For exact details we refer to the website of Lycoming Textron or one of the files below.

Detailed information can be found in the following pdf files: O-235, O-320, O-360, O-540 and for the IO-390, IO-580 and IO-720 engines read this file.

Lycoming is now (2008) planning to certify its engines to run on Mogas: "Lycoming Engines announced an unleaded automotive gasoline approval program for its standard compression ratio O-360 and IO-360 product lines. Unleaded 93 AKI automotive gasoline conforming to either Euro Norm EN228 or ASTM D4814 will be the basis of this Lycoming specified fuel.", according to Diesel Air Newsletter.

Teledyne Continental Motors

Teledyne Continental Motors Inc. located in Mobile Alabama, has been a recognized world leader in the development of aviation products for over 95 years. Their first engine was also a radial, the A-70. They are also known for the Voyager engines in Burt Rutans designed aircraft which flew around the world without refueling.

The range of engines produced, remanufactured, rebuilt goes from the 100 bhp O-200 (available for the LSA market too) to the O-550 series of 375 bhp. They can be bought in geared versions with or without fuel injection and are usually six cylinder types. In fact, the only four cylinder types are the O-200 and the IO-240. The last one has a FADEC engine management and is used on the Liberty aircraft.

Some detailed information on the Teledyne Continental Motors can be read in this pdf file.

Superior Air Parts Inc.

As a subsidiary of Thielert AG, Superior Air Parts, Inc. is the world's leading manufacturer of FAA approved replacement parts for Lycoming and Continental aircraft engines. So they say on their website. Fact is they manufacture some very nice engines in the range of XP-320, XP360 and XP400 models.

Power output is from 150-165 bhp (XP320), 170-185 bhp (XP360) to 220 bhp for the XP400. They have a 'build your own engine program' online so that you can configure your new engine to your liking and financial situation.

Superior also offers a build school where you can build your own engine under supervision of their staff or see your engine being build by Superior trained specialists while you attend a course about engine operation and assembly. This is a great option for the kit aircraft builder.

Teledyne Mattituck Services

Teledyne Mattituck Services is an aftermarket supplier and overhauler of piston engines to the general aviation marketplace. They are part of Teledyne Technologies Company and manufacture the TMX-320, TMX-360, TMX-390 and the TMX-540 experimental and Red Gold aircraft engines. More detailed info in this pdf brochure.