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Charlie, you had me worried there for a minute, it
looked like I would need two auxiliary fuel tanks to get out of the
pattern. I had the Marcotte gear box ready to test and winter arrived here
6 weeks early, so looks like a spring test period now. JohnD
----- Original Message -----
Sent: Saturday, December 14, 2013 9:34
AM
Subject: [FlyRotary] Re: 2 cycle
premix
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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