Yep, if my HP calculations are correct and my aircraft weights what I think
it does, I should pick up 600 fpm rate of climb just on the HP.  Correlates
with your 22 fpm/hp.

Ed

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From: "Charlie England" <ceengland@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, July 21, 2004 6:23 PM
Subject: [FlyRotary] Re: Tracy Report


> Russell Duffy wrote:
>
> >  Since Tracy and I had the same static rpm with the previous props
> > (which were the same made by Performance Prop), I expect I would have
> > the same static he is getting if I had the 74" which I believe he
> > indicated was around 6200 rpm or about 1000 rpm higher than with the
> > old 2.14 and 68x72" prop.  That 1000 rpm increase will translate into
> > approx 30HP more for take off and move the torque from 345 lb-ft to
> > 455 lb-ft or a gain of approx 110 lb-ft torque for take off.
> > According to my spreadsheet that would move the take off HP from
> > around 155 up to 185 for a standard day - in the cooler weather of
> > all, it will be even more impressive.
> >
> >
> > Talking to Tracy about the difference between his B and C setups got
> > me all excited again.  Sounds like he was REALLY happy with the
> > performance difference.
> >
> > There's a fairly simple formula I saw once that converts excess HP to
> > climb rate, given the weight of the plane.  Do you have that?  It
> > would be interesting to see what 30 extra HP would do.
> >
> > Cheers,
> > Rusty (I need a runway)
>
> 1hp=33,000 lb raised 1 foot per minute
>
> A rough number should be 33000/gross weight * excess hp.
>
> @ 1500 lb, 22 fpm per hp, minus small compensation for drag due to
> increased angle of attack.
>
> Does that pass a sanity check?
> Charlie
>
>
>
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>