Steve, if you give me the fuel flow you are seeing at 6300 rpm and manifold pressure, I can give you a pretty good estimate from my spreadsheet of what power you are producing.  Also should you happen to have the Air/Fuel ratio that would be a plus but not essential.

 

Ed

 

From: Stephen Izett

Sent: Tuesday, August 21, 2012 7:23 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: Prop revs

 

Thanks Ed

I've wondered what my Renesis 4 port with a good intake manifold and in flight adjustable prop will produce.

So on a cold day she will hopefully still breath to 7250RPM and maybe approach 200HP?

 

Cheers

 

Steve Izett

 

 

On 21/08/2012, at 11:40 PM, Ed Anderson wrote:

Steve,

 

On a cold morning when I can see 19-20 gph on take off at 6200 rpm, I calculate based on fuel burn rate and an air/fuel ratio of 12.65:1 that I am probably producing around 180-185 HP.  On hot days based on fuel burn of 16.5-17.0 GPH, I calculate around 165-170 HP.

 

The fastest I've ever had the Rv-6A was 200 mph TAS burning round 13.25-14.5 GPH.

 

But, none of this was done on a dyno - its based on fuel burn and rpm and  we all know a rotary can pass through more fuel than is producing power.  Anyhow, it’s the best estimate I have. 

 

Ed

 

From: Stephen Izett

Sent: Tuesday, August 21, 2012 10:31 AM

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: Prop revs

 

Ed

 

Out of interest, what do you think you are getting in HP from your 13B and at what RPM?

 

Steve Izett

 

 

 

On 21/08/2012, at 9:15 PM, Ed Anderson wrote:

I would say you have  winner.  Does of course depend on what prop load you were pulling during static run.

 

I have a fixed pitch 74x88 and a well-tuned older 13B and the best I have ever got static - was 6200 rpm on a cold day.  Normally, I get 6000-6100 rpm. 

 

So depending on your prop, it looks like you are doing great for static rpm.

 

Ed

 

From: Neil Unger

Sent: Monday, August 20, 2012 9:48 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] Prop revs

 

All,

       Looks like I am finally connected after many attempts..  I have a P ported renesis in a glastar that is ready to fly.  Tuning the motor yesterday to find that I cannot get the motor revs over 6300.  I suspected the prop (prince fixed) is too big, but am assured that that is normal as a static load.  Lonnie suggests that once moving the extra revs will appear.  How do I tune the motor for the top end revs?  Any advice?  Neil.

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