Alternative Aircraft Engines or Automotive Engines
The advantages of alternative engines is either issues of power versus price or the builder not wanting to deal with airworthiness directives.
Far and away the three most popular alternative engines today are the Rotax series, Subaru and Mazda series of engines. Rotax engines are designed to operate at rpm's useful for flight and most applications do not require any reduction unit. The Subaru and Mazda engines being automotive require a reduction unit to get the engine rpm's down to an rpm useful for a propeller.
The following list is a source reference where you can make contact for some of the more common alternative engines used on kit-built gyroplanes. You can always use something else if you want- that's why it says experimental in big letters on your gyroplane.
Manufacturer: Engine Type: Contact:
Geo: 62 hp & 92 hp: No known source but these engines have been used on some gyroplanes.
Hirth: 2703-55hp/2706-63hp/F-30-110hp: Gobler-Hirthmotoren Pho:071446074/ Fax:071445415.
Mazda: Rotary-160hp/13B-170hp: Atkins Rotary Specialties www.AtkinsRotary.com.
Rotax: 277-28hp/477-39-41hp/503-45-49hp/582-40-60hp/618-73hp/912-78hp/913-100hp: Lockwood Aviation www.lockwood-aviation.com Pho:800-527-6829.
Subaru: EJ-2.2 & 2.5 Legacy : AAA Small Car World Pho:817-831-0946 or F&S Auto Parts Inc. www.fsautoparts.com
In the 1970's there was a crunch on fuel availability and prices rose and long lines formed to get fuel. The availe aviation fuel also fell and many nations do not have the refining capabilities to produce aviation grade fuels.This lead to a study of using auto fuels safely in aircraft and resulted in an approved stc for conversion to auto fuel in certificated aircraft.
In 2008 gas prices soared to rated that not only affected the ability to fill up at the gas station but directly affected the economic progress of the world's economy. Many people are conducting private and commercial research into new sources of fueling our fossil fueled vehicles that operate as hybrids. One of the most promising is the use of hydrogen or HHO which produces lower emission temperatures and a cleaner burn, producing virtually no hydrocarbon emissions to the atmosphere. If you are looking to truely do some expeimental work with your amature built aircraft or just interested in this type of technology follow the link below.
Aviation Alternative Fuels
Book sources for Alternative Aircraft Engines