Mailing List flyrotary@lancaironline.net Message #9934
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Tracy Report
Date: Tue, 20 Jul 2004 21:24:38 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
Rusty,
 
    I told you and told not to bother Clark when he has the router removing wood from my prop.  Actually, your phone call will probably have induced an unintended modification to the shape which will give me another 525 ft/min rate of climb - but I'll never tell. {:>).
 
 
 Good to hear he is working on it, that means he is about on the schedule he aimed for in May - not too bad, actually quite good.  I think his new helper Judy must be cracking the whip keeping him to his schedule.
 
  Besides, I AM NOT whining ...... just pouting a bit.
 
 
   I'm glad you are going with the same prop as Tracy.  Tracy talked me into trying out a 76x88 - same as you will get - just 2" longer as he initially felt the torque being generated by the C drive would swing it OK.  If not, then I will have Clark cut it back to 74x88.  Being as my aircraft is a bit heavier than yours or Tracy's RV4, the longer prop just might work out to get it accelerating a bit quicker.  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.
 
 
Actually, I'm tearing out my hair trying to figure out why my digitized Fuel Monitoring system is giving me the Flow rate (gal/hour) to within 0.1 % accurate (compared to the pulse train signal says it should indicate), but  the fuel totalizer is off by a factor of 3.  I suspect that because I am using every pulse for measurement that the chip stays in the loop servicing the interrupt routine so much that the counting circuit elsewhere does not get updated as it should.
 
Hopefully, I will have it figured out before the gearbox gets here.
 
 
Ed
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
Sent: Tuesday, July 20, 2004 6:32 PM
Subject: [FlyRotary] Tracy Report

Greetings,
 
I just got a message from Performance Props, wanting to know what my final decision was on the new monster prop.  To answer their question, I called Tracy to see what his feelings were about his new prop, now that he's had a chance to fly it enough to see how it was doing.  He was happy with it, so I asked Clark to make mine just the same 74" D x 88" P.   
 
He's currently deep in the process of installing the Renesis in the RV-4.  The engine is mounted, and he's got the plumbing, and dreaded exhaust left to do.  Sounds like he's really looking forward to the exhaust :-)  
 
He said he knew he wasn't getting any mail from the list, and had tried to re-subscribe, but still got nothing.  Between the engine transplant, and Ed's whining about not being able to fly without a redrive <G>, It didn't sound like he had a lot of time to spend on the list at the moment.  
 
Ed, Clark was working on your prop when I called.  Unfortunately, I heard him say "Oops" before he came to the phone.  It's probably nothing to worry about :-)
 
Rusty (just too hot to go dodge Navy trainers)
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