Yes, Mike, I read that article about the
comparison as well. This was clearly a case of two guys who had more money
than knowledge of the rotary. One eventually had an engine failure which
damaged fortunately only the aircraft – never did hear the cause. So I
personally did not get any indication reading the results that either of the
pilots really understood how to get the best out of their rotary. But, yes,
the powersport engine certainly looked nice – but at $30K it should
{:>).
One the other hand, I personally saw Tracy
Crook win the Sun & Fun 100 air race on two occasions before they decided
to stop the air races because of the embarrassment of his junk yard engine
(yes, this was before his Renesis installation) beating lycomings that in some
cases had $10,000 of additional prep.
Here Tracy
was in a rather dirty airframe (compared to some of the racers), with
automotive muffler hanging in the slip stream and a fixed pitch wooden prop
winning the air races. Didn’t hear anything about it in any of the
aviation publications did you? – too embarrassing to all those Lycoming
owners. So they decided to cancel the air races to preclude further embarrassment
– Yeah! I know they claimed it was due to insurance consideration, Yeah!
Right! {:>)
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On Behalf
Of Mike Wills
Sent: Wednesday, March 04, 2009
10:50 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Fuel
economy -
There was an article in the May 2006 issue of Sport
Aviation. Two RV-8s powered by Powersport Rotaries compared to two of Van's
factory demo RV-8s. Time to climb and speeds were pretty comparable. The rotary
powered airplanes were a little heavier. Fuel consumption for a 160 mile out
and return flight the rotaries burned 12.9 and 11.5 gallons while the Lyc
powered RVs burned 8.9 and 9.5 gallons. Cruise portion of the flight was
rotaries 7.85 and 7.1, Lycs 5.05 and 5.45.
My guess is that if the pilots could have aggressively
leaned the numbers would be closer but the rotaries were
equipped with Powersport's FADEC. No idea what it does with mixture.
Anyway its articles like this that perpetuate the
ideas about rotaries being gas hogs. Until we generate some numbers to
contradict, this is going to be the perception. If you guys generate the
numbers I'll volunteer to write the magazine article!
I should also mention that the Powersport RVs looked
WAYYYY cooler than the Lyc powered RVs!
----- Original Message -----
Sent: Wednesday, March
04, 2009 7:27 AM
Subject: [FlyRotary] Fuel
economy -
Mark wrote:
Most are just plain scared to run their engines lean
of peak where they are able to get close to the
"advertised" bsfc.
That seems to be the rule. I
chatted yesterday with a hangar neighbor with his beautiful Lancair Legacy with
Continental 550. Does he run lean of peak? “Eh-h, well, I tried it,
but it sounded different, and I hear the valves don’t last as long; so I
run it rich of peak. It’s a few more dollars, but cheap
insurance”
Alcohol and possible vapor lock are the only
issues I know of, and with a properly designed EFI fuel system, vapor lock
isn't an issue. As long as they don't start blending alcohol in the
fuel in my neck of the woods, I'll keep burning mogas and pocketing
the difference.
I did the ethanol test on my auto fuel
yesterday. Within the accuracy of the test, the fuel had between 4 and 6%
ethanol – consistent with what Mike said regarding CA fuels. So I
got out my light and little my mirror and stiff wire with a sharp end; and
inspected my fiberglass/EZpoxy fuel tanks. No sign of any softening of the
surfaces; no sign of anything happening. Nothing in the fuel filter. So far, so
good.
So I’ll keep runnin’ with
auto fuel – certainly when near my home base. Saves close to $15
for every hour of flying – including the 6 – 8 cents/ga for the
2-cycle oil (SuperTech 2-stroke oil, $10.97/ga at Walmart, mix ¾ oz per ga.).
You stated, "But really the biggest motivation
was to do something a little different." As for that statement... I
couldn't agree more, but how do you quantify something like that?
I like to put it differently:
"But really the biggest motivation was to do something a little better."
Al G
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