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Old November 25th 08, 10:44 PM posted to rec.aviation.homebuilt
Capt. Geoffrey Thorpe
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Posts: 790
Default Why are low-revving, high torque engines preferred?

"jan olieslagers" wrote in message
...
Oliver Arend schreef:
At the risk of feeding the trolls:
There are several examples of the setup you describe.
The Rotax 4-stroke engines have a (belt?) reduction.
In Europe one sees more and more BMW-motorcycle engines
driving planes through a reduction, either gear or belt.


There are also several versions of Lycoming / Contintntal / other "brand
name" aircraft engines with reduction units.

Adds cost, complexity, and can result in durability issues (one more thing
to go wrong).

Sometimes it works out better, sometimes not. It all depends on the details
of your objectives.

For extra points - why do Ford V8's have overhead cams and Chevy V8's tend
towards pushrods - you would thing that one would be "better", right? Why
are they different?
































Because Ford management gives the engine designers a "horsepower per
displacement" objective and Chevy magement gives them a "horsepower per
package volume" objective.

(per engine guys who have worked at both shops)

--
Geoff
The Sea Hawk at Wow Way d0t Com
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