You have to admit there are a lot of them flying though... Subies, Mazda
Wankels and even Suzuki/Geo engines. I think I draw the line when I see B&S
engines but they are being tried too.
All aircraft engines are to an extent derated. That is why you get less
than 500 hp from a 500ci turbocharged engine. If I was going to use a Subie
I'd derate it by a good percentage and limit the rpm to no more than 5000.
You are right on the fact the engines are designed to be used in cars but
that particular application has to be just about the most punishing
application going. As you no doubt know highway driving is a lot easier on
a car than around town. To me is comes down to this what do I like better
1920's design and engineering... not to mention in some cases rebuilt parts
or Millenium engineering and production... except for the redundancy aspect
that's a no brainer. For the type of fluying most people do I think the
latter is not only sufficient but a good choice. However if you are the
pilot who ventures deep into the boonies then the redundancy of earlier
engines is the way to go.
That's why I could never suggest the use of automotive engines in certified
planes.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of JetPilot
Sent: Tuesday, November 25, 2008 2:39 PM
To: kitfox-list@matronics.com
Subject: Re: Engine choice- O-200 or EJ 22
It makes absolutely no difference if the Subaru was originally designed as
an airplane engine 50 year ago or not. The reality is now that the Subuaru
that the poster is thinking about using in his Kitfox is a CAR engine,
designed and built to run in a car, not an airplane. Even IF it were true
that some engines started life in aviation 50 years ago, the aviation
engineering that were put into the engine would have long ago been taken out
by an auto manufacturer. The modern Subaru engine parts were designed to
be run in a car at around 20 % power for long periods, not at the long 100 %
climbs and 70 % cruise power used in an airplane.
Bottom line, the history of the engine does not mean anything, the modern
design is for a car, and you will have to do a lot of engineering to make it
work at all in a plane, and chances are it will still probably never be
reliable. Many people with a lot more talent and engineering resources than
you have tried to make these engines reliable for aviation use and failed.
It would be best to learn from their experiences.
Mike
--------
"NO FEAR" - If you have no fear you did not go as fast as you
could have !!!
Kolb MK-III Xtra, 912-S
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