what engines are making successful aero engine conversions?

On May 14, 2:38*pm, wrote:
On Wed, 13 May 2009 06:40:13 GMT, Stealth Pilot

wrote:

I'm in Western Australia. locally our supplies of VW engines seem to
have dried up. Even BMW motor cycle engines seem to have dried up.
what other currently available engines have been successfully used in
aircraft?

the engine problem seems to provide the most unsolvable dilema when
attempting to build a small aircraft. I'd hate to think that the
prospect of engine conversions was passing.

Stealth Pilot

Why do we always assume we have to reinvent the wheel? If you need 40
hp, here it is. Even altitude compensating EFI available soon.
Designed for max continuous power. *Rig a PSRU with a poly-v belt for
more efficient prop speed/length.

40 not enough, stack 2 end to end. Have a steel crank made if the iron
makes you nervous.

Neither of these ideas are exactly trivial.

Not every small gas engine is a Briggs. I've run 100s of these Kohlers
for 40 years. Some 2000 hours in a year. Almost all the 30 and 40 year
old garden tractors have Kohlers or Tecumsehs. Not many Briggs.

Model Command PRO CH1000
Max Power @3600 RPM hp (kW) 40 (29.8)
Displacement cu in (cc) 61 (999)
Bore in (mm) 3.5 (90)
Stroke in (mm) 3.1 (78.5)
Peak Torque @ Maximum lbs ft (Nm) 61.5 (83.4)
Compression Ratio 8.8:1
Dry Weight lbs (kg) 132 (59)
Oil Capacity U.S. quarts (L) 2.9 (2.75)
Lubrication Full pressure w/full-flow filter
Dimensions L x W x H in 15.3 x 19.0 x 27.5


For the benefit of our Western Australian friend, http://www.epgengines.com..au/
has a distributorship in WA.

The Generac 990 is in the same class, and is the starting point for
the Valley Engineering Big Twin Re-drive setup.
http://www.brandnewengines.com/gener...391-1-1-2.aspx

One of the problems is there seems to be whole in the market between
30 hp and 80-100. The two examples above are the biggest air-cooled
gasoline industrial engines commonly. There are a (very) few liguid
cooled engines in this range (Kubota and Daihatsu ), they tend to be
substanially heavier. The other problem is the way the emissions and
fuel efficiency have driven car engines to higher RPM and teeny
cylinders.

One idea is run an aluminum block car engine direct drive at low RPM.
A Honda engine of about 1.8L should be able to meet this, say an F-
Series: http://en.wikipedia.org/wiki/Honda_F_engine The later K
series engines are more complex - V-TEC, etc, and probaby are not
wanted. Engine weight should be in the mid-200 lb category. The
smaller D series might be enough, although they are not that much
lighter, say, low 200s for the bare engine. A Suzuki G- or J- Series
might also fit the bill, and since they were fitted to Utes their
torgue band might be lower, better driving a prop.

Another is to direct drive a small truck/industrial engine. Kubota
and Daihatsu make liquid cooled gas engines too small for you, and
Ford and GM make iron block 1.6L engines that are too large.

http://www.gm.com/experience/technol...Industrial.pdf
http://www.fordpowerproducts.com/For...f/1.6LSpec.pdf
Nissan also makes industrial engines in this range.

Suzuki and Subaru engines have been converted, by Americans,
Canadians, Germans and Poles.

http://www.raven-rotor.com/html/specs.html
http://www.airtrikes.net/engines.shtml
http://www.aerotech-poland.com/

On May 13, 1:40*am, Stealth Pilot
wrote:
I'm in Western Australia. locally our supplies of VW engines seem to
have dried up. Even BMW motor cycle engines seem to have dried up.
what other currently available engines have been successfully used in
aircraft?

the engine problem seems to provide the most unsolvable dilema when
attempting to build a small aircraft. I'd hate to think that the
prospect of engine conversions was passing.

Stealth Pilot

A very active group of fellows in Poland are using Moto Guzzi M/C
engines as well as BMW's. Honda marketed a similar type of engine that
has been tinkered around with a bit but most likely needs a different
crank or cam. I have read of one person using a small Honda auto
engine that he replaced the crankshaft in order to get more thrust at
lower rpm's. He didn't use a PSRU. Couldn't on of the three cylinder
Geo engines be modified with a custom crank or cam to do this with the
right prop? Water cooling has advanced a lot in the last few year's
with very light weight radiator's.