Mailing List flyrotary@lancaironline.net Message #44877
From: Greg Ward <gregw@onestopdesign.biz>
Subject: Re: [FlyRotary] HP was : Mark's BBQ Run / 20B numbers
Date: Fri, 23 Jan 2009 07:53:03 -0800
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hey Ed;
We are running a 4088 Garrett hair dryer, starting at about 15# of boost, and are extensively flow testing both the exhaust and induction for best efficiency/output.  That's why the pictures, show everything a little bit different from what everyone else has done.  Trying for optimum runner length, as little back pressure as possible, early heat removal, etc.  Haven't got any real numbers down yet, until we (finally) get on the dyno but based on what a stock 360hp Cosmo gets for mileage, and going from there, we are convinced that fuel flows should be pretty good.  That's why they call it "experimental".....(:-)
Greg
----- Original Message -----
Sent: Friday, January 23, 2009 5:42 AM
Subject: [FlyRotary] HP was : Mark's BBQ Run / 20B numbers

Hi Greg, well, if the fuel burn figure reported was correct - then the HP figures I calculated are in the ball park.

 

We know the 3 rotor is capable of producing considerably more power at sea level (per Al’s dyno run with his 3 rotor) with the higher air density.    However, at altitude the upper limit would naturally be less due to the less dense air to support combustion, unless you are running some sort of forced induction as in a turbo, supercharger or perhaps nitrous oxide chemical enhancement.

 

 But if the fuel burn was 15 gph, then it does not matter whether it was a 2 rotor, 3 rotor or 1 rotor (a 1 rotor would really have to be screaming to burn at that rate {:>)),  the approx HP equation is:

 

HP = (Gallon/Hour) *( 6 lb gasoline/gallon ) /BSFC = 15*6/0.55 = 90/0.55 = 163 HP.

 

Now if you choose a different BSFC such as 0.49 then you get a better conversion.  But, I tend to be conservative in my estimates.

 

Best Regards

 

Ed

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Greg Ward
Sent: Friday, January 23, 2009 12:20 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Mark's BBQ Run / 20B numbers

 

Agree to that. Our projections on the turbo 20B are much higher than that.

Greg

----- Original Message -----

From: Al Gietzen

Sent: Thursday, January 22, 2009 9:13 PM

Subject: [FlyRotary] Re: Mark's BBQ Run / 20B numbers

 

Ed;

 

Seems like your numbers are about 100 hp - or maybe one rotor – too low.

 

Al G

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson
Sent: Thursday, January 22, 2009 8:34 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Mark's BBQ Run / 20B numbers

 

Doug, at 15 gph at 6000 rpm, Mark would be making approx 165 HP, perhaps a bit more, using a very conservative  BSFC of 0.55.  If you assume a bit better BSFC of 0.49 it would be around 183 HP.

 

 

Ed

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of DLOMHEIM@aol.com
Sent: Thursday, January 22, 2009 9:38 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Mark's BBQ Run / 20B numbers

 

Mark:

 

Great story...thanks for posting it!  At 6,000 rpm and 15 gph, how many HP do you think you're developing?

 

Also, have you by chance flown side by side with another Lycoming powered ES for comparison purposes?  If so what did you learn?

 

We're going to have a couple of "burger burns" at our airport ((2OK2) just east of Tinker AFB) this Spring / Summer, so maybe you'll feel like going on a short cross country up this way and show our little EAA chapter what a three rotor looks and sounds like?! 

 

Blue Skies

 

Doug

RV-9A, 13B

Organizing the hanger for Spring FWF and canopy work!

 


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