It's expensive and troublesome adapting car engines to aviation even ignoring the certification cost. Problems are operating altitudes, heat and cooling, loading differences, RPM, fitting the engine inside a cowling, making it compatible with a variety of existing aviation components (vacuum pumps) and so on. It's a lot of things to work out. It adds up.
As far as certification is concerned, people do not realize what is involved with the costs a company must pay if it wants an engine to be certified for aviation beyond experimental and light sport segments. Part of it is FAA lab charges to put the engine on a stand and a few airframes to show it works as advertised. But what people do not realize is that every single part in the engine must also go through an applicable certification process. These costs are placed well upstream of the engine manufacturer in most cases. Such costs reflect the expense of keeping an elaborate paper trail showing extensive details on raw manufacturing stock, finished component testing, adherence to standard for equipment used in manufacturing, and all associated costs such as maintaining records for decades. Aerospace manufacturing is replete with manufacturing controls, tests, paperwork, and regulations not found in automotive manufacturing. This is one of the reasons things change so slowly in the aerospace industry, and are the reason general aviation moves so slowly.
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Continental Motors Reveals Jet-A-Burning Piston Slapper
FLYING eNewsletter (5/20/10) Teledyne Continental Motors (TCM) has unveiled a two-engine project that will bring jet fuel to the light-aircraft industry. The first, a 230-hp four-cylinder engine is expected to be certified next year. A follow-on six-cylinder, 350-hp version could follow as soon as two years later. TCM said the engine program stems from acquired technology — but would not identify which European company the already certified engine technology came from. (According to an article on AvWeb, the TCM engine bears a striking resemblance to the SMA SR305.) Under the license agreement with the original maker, TCM now has free rein to further develop the existing engine as it sees fit. The company has said it expects the new engines to cost not much more than their gasoline-burning counterparts in the same power range. TCM's version is currently undergoing tests on a static test stand and in flight on a Cessna 182 Skylane. Specific fuel consumption (sfc) of the new engines is said to be in the .36 range.
Kerosene Engine Certified in Europe
(AOPA ePilot, Alton K. Marsh, 5/28) Centurion has received a supplemental type certificate (STC) for the installation of the 155 horsepower Centurion 2.0s kerosene-fueled, piston engine in the Cessna 172. The European Aviation Safety Agency (EASA) issued the STC to Centurion, the subsequent sales company to the insolvent Thielert Aircraft Engines GmbH. Cessna models 172F to S can now use the engine. First deliveries begin in June. Certification is expected soon for the Robin DR400 Ecoflyer and Diamond DA40 TDI. The Centurion 2.0s is the more powerful version of the well-established Centurion 2.0. With an identical weight, it generates an additional 20 hp. “Everyone who was impressed by the flight performance of the Cessna 172 with the Centurion 2.0 will be enthusiastic about the Centurion 2.0s,” said Centurion CEO Jasper M. Wolffson. With the Cessna 172S model, the new engine increases the maximum takeoff weight limit from 2,450 pounds to 2,550 pounds. Cruising flight fuel consumption is 6.4 gph at a speed of 115 KTAS (at 70 percent power, 6,000 feet). The takeoff distance over a 50-foot obstacle using the Centurion engine is 1,617 feet. The range with the 44.5 gallon standard tank is 665 nautical miles.