Oops! Fingers faster than brain syndrome. .45 to .48 (.5 to .6 at full power, meaning low altitude, wide open, rated rpm).
Sent from my iPhone What Charlie said. Except move the decimal point left one place.
Tracy
Sent from my iPad
I don't have a rotary flying yet, but
rotaries follow the same physics as other internal combustion
engines. You can estimate your power relatively easily by leaning
for best power & measuring fuel flow. If everything's right,
with good intake & exhaust tuning, and low/mid power settings
like Tracy described, you can expect 4.5 to 4.8 pounds of fuel per
horsepower per hour. More pounds per HP if there are tuning issues
or improper leaning.
Another way to do it with a common airframe like an RV or a
Glastar is to just get honest answers on fuel flow from others who
are flying at the same speed in the same configuration. This is
usually practical only with full throttle numbers, because most
Lycosaur operators are afraid to lean properly. If they are
running full throttle at rated rpm for the engine, you know how
much power they are making for speed X. If you can match the
speed, that's your HP.
Charlie
On 12/13/2013 11:05 PM, Neil Unger wrote:
gents,
Many thanks for the figures. seems that I
may not be too far out at this stage. More flying and
figures from summer turbulence! Takeoff Rpm just over 6300,
I think, and then found the mix was very lean. Had to turn
the mix Knob almost to 2,30 and that fixed the very high
EGT’s as well. The engine seems very happy in cruise at
5300 to 5600 depending on how much fuel you want to use.
5400 rpm and 22.9 MAP and the fuel I havn’t a clue as have
been fiddling to get it to read Litres. Flew over 2 hours,
so will fill the tanks and get an idea at least, but going
at a guess may be around 7.9 Gph at anywhere between 3 and
5000 feet depending on the thermals. I have a glastar, so
only expecting 130 Kts. Currently getting about 110 or
possibly better. Then I have removed the wheel spats for
flight testing in case I had to land in someones rough
paddock, so that may be a loss of 5 kts or more, then
obviously have too much cooling drag as today with 8 inches
of my water exchanger blocked off, I could only get the
water to 160 degrees and oil at 155 degrees, and that is at
OAT of high 80’s. Now to experiment at how much I can block
off the inlet to get temps up to 185. Tracy, your gear is
brilliant, congratulations. Neil.
Sent: Saturday, December 14, 2013 3:30 PM
Subject: [FlyRotary] Re: 2 cycle premix
I get about 185 mph and 8 GPH with
my Lancair Legacy FG with the Renesis at about
5800-6000 RPM, but I doubt I could get 224 mph in a
dive! :>)
Bill
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On Behalf Of Tracy
Sent:
Friday, December 13, 2013 9:02 PM
To:
Rotary motors in
aircraft
Subject:
[FlyRotary] Re: 2 cycle premix
Speed about
165 - 175 mph, 6.5 - 7.5 GPH. These are the
Renesis numbers on RV-4, not the 20B RV-8.
Tracy:
what speed and fuel burn at your cruise settings
Kind Regards
I typically cruise at 5400 - 5600
rpm. WOT at top speed (224 mph) rpm is
7250.
If you are happy with 6000 for
take off, What rpm do you cruise
at? Did you ever manage to get
the monitor to record litres??
Neil.
Sent: Thursday, December
12, 2013 9:33 AM
Subject: [FlyRotary] Re: 2
cycle premix
Using a 74 x 88
2blade on my Renesis. I get
about 6000 on takeoff so I would
not say you have too much
prop. possibly too little if
that 6800 rpm is accurate.
1800 EGT is not unusual at peak
EGT & WOT.
finally flying again,
but my prop is too big.
It is a 70” dia by 90
inch pitch. Max revs on
takeoff is about 6800
and the EGT is pushing
over the 1850 degrees.
Obviously the prop is
too big as revs are
restricted and the motor
is working too hard
hence the EGT. What
size props are you
people running?? 2
rotor renesis. Neil.
Sent: Thursday,
August 08, 2013
7:12 AM
Subject: [FlyRotary]
Re: 2 cycle premix
I use
the same mix, but at
closer to 1 oz/gal.
Why? That is what Tracy
does. Dont think it
is very critical over
the short term. I
have gone without oil
for a tank or two when
I didn't plan well. I
have also put
multi-weight aviation
engine oil in (at .5
oz/gal) on one
occasion when I forgot
to bring along any
2-stroke oil at all.
On
Fri, Jul 26, 2013 at
11:39 AM, Bill
Bradburry <bbradburry@bellsouth.net>
wrote:
I use the
same mix as Dennis
but at the rate of
3/4 oz/gal in
non-ethanol auto
gas. My engine is
a Renesis with 70
flight hours.
Bill B
From:
Rotary
motors in
aircraft
[mailto:flyrotary@lancaironline.net]
On
Behalf Of Clouduster
Sent:
Friday, July 26,
2013 9:17 AM
To:
Rotary
motors in
aircraft
Subject:
[FlyRotary] Re:
2 cycle premix
I use a
50 - 50 mix of
MM and WalMart
2 stroke @
0.50 oz/ gal.
Mixed in auto
gas. My
engine is a
Renesis with
500 +hrs.
Dennis
H.
Sent from my
iPad
For
those of you
who are
actually
flying and
have some time
on your
rotaries and
are using
Pre-mix 2
cycle oil:
1) what
oil are you
using
3)
what ratios
are you using
4
where is the
best place to
get it
--
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
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