flyrotary@lancaironline.net Mailing List Archive

Even so, Tracy, a HUGE advantage at take off, acceleration and climb are attractive to me even if top end speed suffered a small bit. I only fly top speed to see what the top speed is and then normally fly around 170-180 mph TAS. However, having greater get up and go on take off (which is the only place spectators would see it anyway {:>)) would be sufficient to make the switch attractive to me. Assuming, of course, you don't find any "gotchas" along they way with the 2.85

Ed.

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

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

From: Tracy Crook

To: Rotary motors in aircraft

Sent: Wednesday, March 24, 2004 11:01 AM

Subject: [FlyRotary] Re: Renesis & RD-1Cdrivetesting

Charlie's observations are right in line with what I have seen so far.   Still, I would not want to give up the ability to do wheel landings comfortably. 74" is at the limit for my -4. The -8 or the -4 with the updated longer gear would not have this problem.   The -8 I'm building will have nothing less than 76" prop and more if I can get it.

As I accumulate more hours I clearly see the trend. Huge advantage at low speeds (acceleration & climb) but advantage diminishes as speed approached maximum.   With the IVO prop (72" dia) I saw the same thing but the advantage diminished to zero at about 140 mph and then became negative above that.

I still have not run the new drive & prop to top speed. I attempted to yesterday evening but the dreaded SAG (Sparkplug Attention Getter as Ed calls it) struck as I was approaching 220 MPH.   My best guess is that the zero point (same performance as with -B drive) is right at this speed.   Things may improve after I get the cuffs built (today's project).

BTW, this -C drive stuff is very encouraging but it's way too early to close the books on this. One week of testing does not prove anything about long term effects.   It's always the unexpected things that are the bane of the experimenters' life. The 13B tension bolt problem took over 1000 hours to show up. I'll be flying on "Orange Alert" status for hundreds of hours before I feel as comfortable as I did with the -B drive.

Tracy Crook