Greetings,
I made a couple more
flights today, and have a few comments about the rev-2 configuration.
The best news is that I
haven't had one single leak, loose bolt, or other issue with the new
configuration. I'm actually comfortable enough to venture away from the
airport now.
The other best news is
that cooling is a complete non-issue. With 82 F ambient temps, I
couldn't overheat the water or oil if I tried. The highest I've seen oil
is 180 F, and water was maybe 160 F. I'm still running distilled water,
so when I add some coolant, it will probably heat up a little. It will
also get about 20 degrees hotter in the next couple months, so that won't help
either. I'm willing to bet that cooling will still work well enough to
install the cowl cheek extensions.
More good news- the
handling is much better now that that 42 lbs is gone from the nose. It
actually flies like an RV, and stall speed is down a few MPH as
well.
I've got all the wheel
pant brackets installed now, but haven't installed the wheel pants
yet. I'm certain that the pants, and gear fairings will make a
large difference in speed (15-20 mph), and perhaps even climb. I
also need to install the gear leg stiffeners due to some shimmy that I'm
having. Currently, the speed is 170 mph TAS at full throttle, regardless
of prop pitch it seems. This is as fast as it ever was before, so the
lack of a turbo doesn't seem to be hurting me here. At 13 degrees, the
rpm is 6700, and at 15 degrees, the rpm is 6200. Once I get the airframe
cleaned up, I'll feed the numbers to Warp Drive, and let them taper
the blades. They claim the tapering will add about 4 degrees of
effective pitch to high speed, but have virtually no effect
on climb. I've actually read comments by owners who say this is
really true, and that it acts almost like a CS prop. We shall
see.
The worst news is
probably climb performance. The best I can manage now is 1500 fpm, which
is still at only 100 mph. I'm hoping the wheel pants and fairings will
improve this, and put it back in the 120 mph range where you would expect it
to be. Either way, it's unlikely that I'll ever make it back to 2700 fpm
like it was with the turbo. It does appear that the turbo was pulling
it's own weight, but I'm still happy to be rid of it. This is
another area where the prop pitch baffles me. You would think that
reducing pitch, and increasing rpm would help climb, but that just isn't the
case. At 13 degrees, the best climb was 1000 fpm, at 5400 rpm, and
100 mph. At 15 degrees, best climb is 1500 fpm, at 5100 rpm, and 100
mph. I just do NOT understand this, but it also happened
back with the turbo. Is it possible that this is just something
goofy about the Warp Drive prop? I want to run the engine at
higher rpms, but neither speed, nor climb improves. Am I
losing all the extra power on the prop?
Finally (I heard that
sigh of relief), I'm not convinced that the long intake runners are causing me
any real harm (another sigh of relief heard from Paul). Throttle
response is not that bad, and I've been monitoring the temp of
the runners. So far, the temp has remained right around
ambient. The only thing I'm wondering about are some high EGT's.
This was something that was mentioned as a result of this long intake
scheme, and I can easily exceed 1800 degrees. Which brings me to a
question:
I'm running along at
normal mixture, and settle into a cruise configuration. When I
start to lean the mixture, EGT's go immediately up to 1800 plus degrees
(about 10 inches from the port). This trips the alarm that
Tracy had pre-set in the EM-2, and I richened it back up. What
should I shoot for on leaning the rotary? Is there a rule of thumb such
as X number of degrees on the rich side of peak
EGT?
Thanks for any
comments.
Cheers,
Rusty (driving to
Cleveland all day tomorrow)