Hi Rino,
I don’t have a Renesis but, I am surprised
that you could only get 11.7 GPH burn at 6400 rpm. In fact, I am surprised
that you could achieve 6400 rpm at that fuel burn in a Glass Goose and still
get off the water (or are you only doing land takes at the moment) –
but, then that of course depends on the prop load and other factors.
If fact at only 6000 rpm, 11.7 GPH would
only give you an air/fuel ratio of roughly 21:1 – a very, very lean
mixture especially for take off, especially from water and approx 124 HP.
Are there any other indicators of performance, rate of climb, top speed? In comparison
with other Glass Goose? Do you have an air/fuel
ratio indicator??
My first suggested would be to calibrate
your EM2. It would appear to me that its unlikely you are only producing 124
HP. What is the nominal HP one finds in a Glass Goose? What size Lycoming
for example?
I would hate to see you doing a lot
of work only to find out that the fuel burn rate being reported by the EM2 is
erroneous due to lack of calibration. Its tough know where to look for a
problem or to make decisions, if you are not certain of the data.
My 13B will nominally show 17-18 gph at
6000 -6200 rpm on take off roll and on a cold <40F morning has shown as much
as 19-20 gph. I am using a 2.85:1 redrive - swinging a 74x88 two blade
wooden prop.
How much manifold pressure? What
type of prop? How many blades, pitch? Adjustable in flight??
You mention 17” of runners –
what distance does that measure? I always measure from the block entrance
to the center of the Throttle body and then I add 2.5” for the distance
from the face of the block to the actually opening to the combustion
chamber. Based on that I have runners that are 22” long, but
that length was my calculation for best power at around 6000 rpm. Best
power at higher rpm would, of course, not need as long a runner.
More details on your installation would
help us try to help you.
Ed
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Rino
Sent: Thursday, November 27, 2008
6:32 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Renesis fuel
burn
Where can I get information on fuel burn and power for the
renesis?
The maximum fuel burn I can get on takeoff is 11.7 gph
(reading on the EM2) at 64 00 rpm. The EM2 is not fully calibrated
yet! I think I should be able to get a higher fuel burn than that.
The other part of the problem. What should be the
intake manifold runner length on the Renesis. Best power has to
be between 6000 and 6500 rpm limited by the propeller and redrive
configuration. I cannot use more than 65" dia. prop.
The present runner length is 17" and I think it is not
enough.
Renesis powered Glass Goose
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