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Greg, Sounds like you are about to enter the "Fun
Zone".
This may have been mentioned before, but, if you are
going to turbocharge your 20B be advised the stock turbochargers are simply not
designed and will not withstand (for long) the stress of continuous high
altitude boost. Several folks have tried it with the stock 2 rotor turbo
only to have the turbine section demonstrate its inability to withstand the
stress. It appears that at least one individual has managed to keep his
stock turbo installation intact by running low levels of boost < 5 psi.
Several have found that a set of modifications to the stock turbo compressor and
turbine section can improve its survivability, but probably best to go with a
turbocharger designed for continuous high power operation.
Others may want to chime in here to point Greg down the
right path. Two fellows from South Carolina have a turbo 20B that was
dynoed to over 500 HPthey have in a Lancair 4.
Its really going to be a moving machine.
Good luck
Ed
----- Original Message -----
Sent: Monday, February 11, 2008 1:50
AM
Subject: [FlyRotary] Re: Fuel burn
O.K., time to throw a little F matter into the
fan. I am sitting in my new shop, with a Lancair Legacy RG, and a
relatively new 20B "D" series on a palette. I got the engine complete
with everything it had in the Cosmo that it came out of. There isn't
even a coat of grease on this thing. Radiator, oil cooler, air
conditioner, condenser, ECU, injectors, coils, motor mounts, and about 100
pounds of extra stuff came with it. My buddy (he has been selling
engines for 15 years) in LA that sold me this engine ($4500.00) is in
constant contact with people who race this motor, and I am getting a lot of
input on how to set this thing up. I have ordered Tracy's gear drive,
and plan on generating 400 HP on take -off, and about 75-80% at
cruise. My max rpm will be 8000. You have no idea how much input
I am getting from the racing set. They are saying that with
a variable boost (electronic) controller, I can vary the boost at any
given altitude, as much or as little as I want, and tweak this thing for max
performance. They can't believe that I am asking so little from this
engine.
This will get us started;
Greg
----- Original Message -----
Sent: Sunday, February 10, 2008 7:14
PM
Subject: [FlyRotary] Re: Fuel
burn
Yeah, I would be interested in this one too, as I am
looking at prop options too.
Greg
(Lancair, on the ground, in the new shop, mating
with a 20B as of this weekend....(:-)
----- Original Message -----
Sent: Sunday, February 10, 2008
4:06 PM
Subject: [FlyRotary] Re: Fuel
burn
Hi Mark,
Isn't 7000/2.85=2456.14 ??
Is the
M/T optimized (diameter, pitch, twist) for turning only
2150rpm?
Charlie
Mark Steitle wrote:
Al,
Yes, I'm running one of Tracy's 2.85:1.00
boxes.
Mark
On Feb 10, 2008 12:20 PM, Al Gietzen < ALVentures@cox.net> wrote:
Subject: [FlyRotary] Re: Fuel
burn
Thanks, good data Al. I'm sure
that some of the differences we're seeing are due to altitude.
So far, I've stayed fairly low (3000-5000'). I may try some
higher altitude flight soon just to see how it changes my
performance numbers. Another difference is that I have a M/T
electric constant speed prop. I normally set it to 2150rpm for
takeoff. This allows the engine to turn around 7000 rpm, which
will account some for the higher fuel burn I'm seeing. My
airport is at 520' msl, so there's a 1000' difference there from
your 1500' msl airport. Yes, she really accelerates down the
runway. I'm usually airborne in about 900-1000'.
Mark
I'm not
sure I see how these correlate "set it to 2150rpm for
takeoff. This allows the engine to turn around 7000 rpm,"; but the big difference is that
you're putting out more horses than I am. At 7000 you're
likely looking at about 300 hp, so 25-26 gph would be expected.
Are you running a 2.85 ratio redrive; or something
else?
Al
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