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Sounds great thus far, Tracy
Imagine having so much thrust that you
can't hold the aircraft still for maximum static, must be tough {:>).
If you initial observations hold regarding fuel consumption and performance,
then I predict the 2.85 will soon become the standard. If the fuel
burn/performance is a wash then only engine wear from higher rpm might be a
factor, but since the rotary seems to only have no/ minimum wear in any
case, that probably will not be a significant factor.
So how much are you given for 2.17:1 trade
ins? Seriously, will the B model mounting plate accommodate the C model
gear box housing (looks like you mount it the same way). I presume it
would not be so simple as swapping out the internals as I am certain the
internal mounting/housing is different in the two. Third, in case
you consider getting rid of that old performance prop, put me on top of your
list.
Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
Sent: Sunday, March 21, 2004 9:12
PM
Subject: [FlyRotary] Re: Data? Was :
Renesis & RD-1C drive testing
Hi Ed,
Wish I had more carefully documented fuel burn vs airspeed on the -B
drive & old prop. But from the few well documented points that I
have, it looks about the same at 6.0 GPH (sea level) IAS, 143 - 148 depending
on OAT, humidity, etc (its amazing how much conditions affect things).
This is the only point I've had a chance to compare so far. I have not
built the prop blade cuffs that I feel will be necessary to get best
performance from this combination. Clark at Performance Props was very
honest about the difficulty in getting the proper pitch at the blade
root (out to ~ 3" past the 13" dia. spinner) with pitch this high.
This being the case, I'm very happy with the results so far.
Other conclusions are that anything less than 74" L prop is a waste on
the -C drive. More would be better but that's as long as the -4 prop
clearance would allow.
I can't measure static rpm (plane wants to skid on grass and/or nose
over) but climb RPM is at 6200 at 120 mph (up from about 5200 with -B drive)
and VSI is pegged (hard!). Only did very brief test of WOT in level
flight and engine hit 7050 rpm. IAS was still climbing at 215 mph.
Oil cooling has suffered due to stalled air around prop hub and reversed
spiral of airflow due to RH prop. Erased several years of tweaking inlet
shapes.
Most unexpected finding so far is the radically improved glide at idle
setting. Have no clue why. Would have expected worse instead of
better.
Tracy
Hi Tracy,
Experimentation can sure get
exciting quickly, that's for sure. So here we have the first
successful cross-runway take off at Shady Bend,
congratulations!
I am interested in your static rpm with
the 13B engine, big prop and 2.85 drive, so I can calculate an
approximation of your HP on take off - might be interesting to see how it
stacks up against the old set up. Later on of course interested in
your fuel burn at same indicated airspeeds and altitudes for a
comparison with your old set up.
Best Regards
Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
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