22 Vol.4 No.2 / Februar y 2015
ENGINES FOR HOMEBUILDERS ON A BUDGET
toothed belt reduction with a proprietary "soft" coupling in the
prop sprocket. Jeron Smith, Raven's principal, expressed a desire
at AirVenture to fi nd a buyer or partner to take over the engine
part of his business so he can get back to working on his aircraft
project, which is what got him into the engine business to begin
with.
www.Raven-Rotor.com
Aeromomentum Aircraft Engines is a new source for Suzuki
engine conversions. It has a source for new engines that it has
used for quite a while in the marine part of its business. The four-
cylinder engines are available in upright and 70-degree slanted
versions. Aeromomentum has its own custom gear reduction unit
and a refl ashed electronic fuel injection (EFI) computer. These
engines are slightly heavier than the EFI 100-hp Rotax but at less
than half the price.
www.Aeromomentum.com/
Air Trikes supplies gearboxes and other components
for Suzuki, Fit, BMW, and other engine conversions.
www.AirTrikes.net/engines.shtml
Autofl ight is a New Zealand company that makes gearboxes for
Subaru and other engines.
www.Autofl ight.co.nz/reduction
Cam Drive auto engine conversions have been around for a
while.
http://Firewall.ca/index.html
Airfl ow Performance has been making mechanical fuel injec-
tion systems for experimental aircraft for a number of years.
www.Airfl owPerformance.com/html/site_html.html
Simple Digital System makes electronic fuel injection/ignition
systems that are well suited to and used on experimental aircraft.
Ross Farnam, the owner, thinks enough of his product to fl y the
SDS-equipped Subaru-powered RV that he built. There is much
useful info on the website.
www.SDSefi .com
Rotax, Hirth, Compact Radial, and Simonini gearboxes have
also been adapted to other engines.
Where are the Wankel rotary engines? They are out fl ying
and more are being built. Thanks to Mazda, there are rebuildable
cores available, and they are some of the easiest, least expensive
engines to rebuild. It is very much an experimenter's engine.
The best single source of information is Paul Lamar's website.
www.RotaryEng.net
Some of the aforementioned gearbox suppliers have reduction
units for the Mazda Wankels. One of the pioneers of rotary con-
versions was Lou Ross. He developed a propeller speed reduction
unit (PSRU) based on a planetary gear set from a Ford automatic
transmission. After Lou passed away, it was improved and a new
version was available from Tracy Crook, who has retired, again
making the lightweight PSRU unavailable. Patrick Panzera, the
former editor of Experimenter and publisher and editor of Contact!
magazine, has stepped up to make the planetary PSRU available
once more. If you have any interest in alternative aircraft engines,
the best source of information is Pat's Contact! magazine. You can
catch up with back issues and there are four volumes available of
the best articles.
www.ContactMagazine.com
Other rotary engines include:
Rotron, a small Wankel.
www.RotronAero.com
Woelfl e Rotary, a small Wankel derived from a kart racing
engine.
www.Woelfl e-Engineering.com
The Verner JCV 360 is a compact, liquid-cooled fl at twin four-stroke engine of 35
hp and 60 pounds. It is successfully fl ying some single-place light aircraft such as
powered parachutes.
UL Power has added modern features to its conventional light aircraft engine
confi guration, which will aid its acceptance as the engine proves its airworthiness.
Photography courtesy of Murry Rozansky