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Message
Bobby answered the "how much HP" question with the HP chart
Thanks for the chart
Bobby.
- Looked like 112 HP at 4000
to me which is the RPM I would target. That was also with a stock
manifold. With an intake manifold optimized for 4000 and adding a few
ponies for a less restrictive exhaust system, I think 120 is do-able.
And I think it could come in at least 50 lbs lighter than a Lyc O
- 320. Another 5 or more pounds off the prop too. And
that's normally aspirated. Turboing to 150 HP would be conservative.
Only down side is the ~ 56 - 58" prop you would have to use. That
would cost some takeoff & climb performance.
This is all
interesting, but I still think the geared single rotor is a better choice for
the 100 HP range. It will definitely be lighter than the direct drive two
rotor, and will allow standard aircraft prop RPM's. It too can be turboed
to 150 HP with ease if that's what you need. There's only that nasty
torque reversal to deal with, but certainly that can be worked out. Once
above 3000 rpm, it's smooth as silk assuming proper
balancing.
When thinking
about the weight, don't forget that you don't give up the full weight of
the redrive. You will still have to have an external thrust
bearing and prop hub, as well as a way to hold the starter. I'm
guessing you might only save 30 lbs over the weight of a redrive, but
you'll be losing half the power. Doesn't seem like a very good deal to
me.
Tracy (why the hell am I talking people out of gear drives
:>)
I'm not sure
you "have" talked anyone out of a gear drive yet :-)
Rusty
(thawing in the hotel)
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