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Jim,
First of all, I'm just now checking my email - I'll give you a call tommorrow to firm up plans for transportation.
Second, I think you and Ed are seeing real gains. I raced motorcycles for 20 years (until it just got to be too PAINFUL to fall off!!!) and we would see REAL power degredation as the day heated up. Here is why: as the charge became less dense (temps rising) the mixture would become richer, moving a 2-
stroke out of the sweet spot for power. Note that the 4-stroke bikes did not seem to be affected by this as severely so this seems to be especially true of 2-strokes and I suspect Lyc's. Now I know that Tracy's EFI takes pressure into account, but... Also, I am suspicious that a 'ported' engine (vs. a 'valved' engine) is more susceptible to this behavior. However, this is purely a SWAG and I have no scientific proof - purely based on observations (which are a form of science, but worthless without the explanation of 'why').
Ken Powell
Bob,
Me thinks you couldn't be more right :o( Me thinks I couldn't
be more embarrassed {{:<(( A bit off is one thing, off by an
order of magnitude is another. Forgot the sanity check and just
flailed away at it. So there has to be some other explanation
why Ed's Mazda and my Lyc behave so much better on cold days.
Back to the drawing board ... Jim S.
Bob Darrah wrote:
> Jim, me thinks you might be off by a decimal place or two in
> your rate of climb increase figures. I figure an additional
> 33 fpm (total 1033fpm) with a 2hp increase. Also just a
> theoryBob Darrah
>
> ----- Original Message -----
> From: Jim Sower
> To: Rotary motors in aircraft
> Sent: Tuesday, September 23, 2003 9:19 AM
> Subject: [FlyRotary] Re: Power on a cold day was Re:
> [FlyRotary] Re:Some turbo thoughts from a pro ....
>
>
>
> True. But that 2% increase in power is ALL EXCESS
> THRUST (over and above what it takes to hold exactly
> what you've got - say 90 kts and 1000 fpm climb).
> Two hp would be 66000 #'/min which with a 2000#
> airplane produces 3300 fpm rate of climb - ABOVE
> what you started with !! Just a theory .... Jim S.
>
--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
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