Continental and Lycoming build **** they need to have there faces slapped. Toyota 4 banger would be a good option.

Taking your comment seriously for the sake of discussion, car engines were designed for different design objectives. There are and were many variables to consider even before avgas became a hot topic. The basic design aspects of a Lyco or Continental horizontally-opposed engine were nailed down over 70 years ago perhaps, but it was an evolution based on aviation requirements through-and-through. Here's a pretty good wiki article on it. I would say form factor and RPM operating ranges are the main differences, but there are many things to consider.

Aircaft engines (wikipedia)

It's not a totally crazy idea however. There have been automobile engines retrofits to modern piston airplanes in a couple of cases, with limited success. The Theilert diesels Diamond used for a few years in the DiamondStar twin was a car engine.

Toyota 4 banger aluminum block etc all the weight reduction in mind and a reduction gear box, a reliable one like on the PT6.

I know a car engine doesn't sit all day at 2350 like a a/c engine does but im sure it could last way past a 2000 hour TBO.

The TBO figure for most Lycos and Cont's is a recommended figure and is not actually a mandated overhaul time. Many of these engines have not been overhauled for several multiples of their TBO times. I do not agree with it as a practice, just to point out that the engines themselves can go the distance.

If you assume a 30 miles per hour average speed for the average car engine, then it goes about 60,000 miles in 2,000 hours. If it lasts for say, 120,000 miles or 4,000 operating hours, this equals two TBO-periods for an aircraft engine of the same sort. The latter are often still found in service, with regular overhauls of course, after as many as 6 TBO cycles. I get this number by dividing a hypopthetical piston airplane with 12,000 hours on it by 2,000 hours. Lots of these airplanes exist and many have the original engines.

If you consider a topend overhaul going the distance.

biofuel airplane from Durban
 

[Biofuel-capable South African] aircraft takes to sky


Barbara Cole 12/09/09, Daily News The first all South African-designed and manufactured aircraft is to be launched in Durban, South Africa next year. "This will probably be the best, most advanced, general aviation aircraft of its class in the world. It is totally state-of-the-art," said Richard Schulz, managing director of Adept Airmotive, based at Virginia Airport, Durban North. "Our timing is brilliant and we have stolen a march on the Americans and the rest of the industry who have cut their research and development budgets because of the recession. "This takes design and manufacturing to a new level," said Schulz, who is eyeing the international market.

General aviation is one of the biggest sectors in South Africa and refers to fixed-wing, non-scheduled aircraft. The way in which existing conventional engines, which come from America, have been built has not changed in 40 years, apart from "some progress" with very light aircraft, Schulz explained. Now, all that is about to change. The four-seater fuselage of the all-South African plane is a SA Ravin 500, manufactured from the most advanced composite material, which is lighter, stiffer and stronger than that used in existing aircraft. The avionics - the instruments - in the cockpit are also the most technologically advanced. The airframe is manufactured in Pretoria and the avionics are produced in Cape Town. The "completely new generation" engine, which has been specially designed and developed to go in the Ravin, but can also be fitted to other fixed-wing planes and helicopters, has been produced by Adept Airmotive, although some of the machining was outsourced to companies in Cape Town and Pretoria. Schultz is hoping to consolidate every aspect of manufacture in Durban next year. He has been in discussions with Trade and Investment KZN about establishing an aviation industry in the province.

His company's engine, which is 60kg lighter than conventional engines, has the most modern internal combustion technology and advanced materials and processes. The 320-horsepower engine burns less fuel than existing engines, and it is environmentally friendly. It runs on any fuel (except diesel), lead-free fuel, ordinary vehicle fuel and bio-ethanol. The engine is liquid-cooled as opposed to air-cooled, making it more reliable and more fuel-efficient. And its fuel consumption in cruise mode is 37 liters per hour, compared with 55-60 liters an hour in existing planes. "No other aircraft in its class can fly 2,700 nautical miles (4,995km) without refueling," said Schultz.

Members of the company's design team, headed by Raymond Bakker, were named Best Inventors of the Year in 2008 in a global award for advanced computer-aided design (CAD). Schulz began working on the engine about 10 years ago. When he ran out of money, an equity investor, Andrew Schoeman, put R5-million into the project. Another R10,5m came from the Department of Science and Technology's Innovation Fund. Now he is looking for further investment funding to take the project into full commercial production. "There has been huge interest from people who want to put the engine into existing aircraft. And we have potential orders from all over the world." Each plane will sell for R2,5m, half the price of a comparable aircraft sourced from overseas, he said. "The potential is that we can manufacture 200 a year by 2015," said Schulz. The aircraft will be unveiled at Virginia Airport [in Durban] in March or April next year.

Swift fuel coming swiftly...
 

Swift Fuel prepares for flight tests

By Dave Hirschman (AOPA Online) Swift Enterprises has announced Dec. 14 that it will begin large-scale tests of its unleaded, renewable fuel that it hopes to offer as a drop-in replacement for avgas. The Indiana-based company uses biomass such as sorghum and switch grass to produce a high-octane fuel that it says could replace leaded avgas in piston-engine airplanes. The fuel has been tested in FAA and independent laboratories and flown in a few Experimental-category airplanes. The test program will be coordinated with the FAA, and an extensive series of flight tests, data gathering, and evaluations must be conducted before the fuel known as 100SF can be certified for broad use in the general aviation fleet. Swift officials said the tests will begin as soon as the company receives FAA approval, and the tests themselves are likely to last up to two years. Engine and airframe manufacturers with sophisticated data gathering equipment will perform the bulk of the flight tests. Unlike other unleaded fuels, 100SF has an octane rating as high as avgas. Swift Enterprises has built a pilot plant in West Lafayette, Ind., the company says can produce about 200 gallons of 100SF a day. Swift officials say 100SF will be “comparably priced, environmentally friendlier, and more fuel efficient” than avgas.

As far as the fuels, "Comparably priced" ain't good enough. We need to break the 100LL racket for good, for the sake of GA. I'm sick and tired of flying beat-out 70 y/o technology lycos and continentals because they don't want to allow competition come in and eat their lunches. So we gotta live with "affordable" 4 time overhauled, lead fouled contraption while paying horrible economies of scales premium on highly toxic gas the industry would be better off phasing out already.

I run 87 octane unleaded on my O-200 and it loves it. 100LL has about 4 times the lead content the engine was designed to manage, yet aviation "red" 87 ceased to exist eons ago, and I'm forced to keep the continental with the busted carb, manual mixture and expensive overhaul barriers. Even so, I have a full 50% cost reduction by running 87 unleaded versus 100LL and since the engine is of low compression, I'm not paying a premium for octane I'm not taking advantage of and extra lead I don't need in my engine anyways. What does industry do in reaction? Stifle efforts to make unleaded available to GA. No pumps at the airport and I gotta jump through hoops to find non-ethanol gas outside and once I do, I gotta cart it to the airplane as if I was stealing something. This works for me since a C-150 only holds 22.5 usable, but for high capacity airframes, yeah the pain of going through that hoop stifles momentum for the average owner (never mind part 135 you can't even use mogas per regulatory schemes).

Lyco and continental just don't want to let the gig up and for the sake of GA we need to break that cartel. In 2009 it is just completely artificial to have to accept TEL on our engines for some anachronistic 70year old design consideration to valve seating (which I've barely paid attention anymore on my O-200 as I run almost exclusively on unleaded). We should have been running on unleaded-designed engines a long time ago. Bio fuels and fancy alternatives is fine, knock yourself out, but we should make the use of automotive unleaded widespread. It's good to hear the guys in south africa are making progress to that end, engine wise.

I just flew a rotax equipped experimental today and I burned 4 gallons of 87 unleaded for 1.5 hours of cheap pure flying fun. No carb heat, no mixture control, no lead fouling, no $4.50/gal price of entry to do what I love. Only thing I need is to get 1970s era production numbers on unleaded engine technology and we can truly get the experimental category becoming market price setters and kill off these leaded gas dinosaurs for good.

Comparably priced is just a starting point...you have to get there in order to have any hope of penetrating the market.

But the beauty of most of these alternatives is that they are renewable...once economy-of-scale drives the prices down they will stay there. There will be no underlying non-renewable commodity cost to spiral out of control (ie oil).

Most folks are looking at biomass based feed stock...totally renewable. If the demand goes up, you just grow more. The only possible cost variable might be some energy required to refine the stuff, but hopefully grid power will become less reliant on fossil fuels also.

The problem with piston singles since about 1975 is they are not scrapped out in high enough numbers to be replaced by modernized units like cars and trucks are. That Skycatcher sold in 2010 will still be tied down somewhere in the local airport world in 2050, perhaps with an owner hauling mogas through the fence at midnight to fuel it. There is no conspiracy, just insufficient numbers to flush the system of older airplanes.

A lot of the price of leaded avgas is in the heavy taxes, the tiny scale of production, and the fact it is not traded as a commodity. The cost of the lead content is a fairly minor factor. Switching the GA fleet over to no-lead engines will not change the price of avgas very much if at all. The only way to get a serious drop in the price of avgas is to do away with avgas altogether and go to mogas. That is not going to happen, but more power to those who have the biceps to haul it from the mini-mart.

The main motivation for biofuels is having something ready when the EPA finally says "no more lead", and when as Rick points out there is another huge dip in the production of oil. Cheap avgas isn't the only goal although it would be nice.

We presently have a bonus depreciation tax break to spur new airplane sales. See AOPA Bonus Depreciation article 1 and AOPA Bonus Depreciation article 2. The problem with this is it only applies to business aircraft and I think, aircraft costing over $200k; it does nothing to sell sport planes or remove any lead burners from the market. There needs to be a cash for clunkers offer extended to outdated piston airplanes added to the existing tax depreciation incentive. This would help get rid of the lead burners, stimulate sales of new aircraft, and stimulate R&D in one move. Bring in your Lyco 360 and go out with the no-lead version, or get a relatively inexpensive brand-new airplane.