I agree with Ed's assessment Ken. The 20B is the natural choice for
the -10.
You would also have a difficult time getting the CG right with
the Renesis. My -4 is at the aft CG limit with
the Renesis (with a 220 lb passenger and NO baggage). The -10 would
require a REALLY long cowl & engine mount to make it come out
right. I would not even THINK of fixing the problem with
ballast. Goes against my constitution : )
OTOH, a 210 - 230 HP NA Renesis (fairly easy to do) would
perform pretty well in the -10 if you were to build the long nose that it
needed. Van initially offered a 210 HP (Cont. engine) option for the
-10 but dropped it when no one went for it.
Tracy
----- Original Message -----
Sent: Friday, January 06, 2006 8:42
AM
Subject: [FlyRotary] Re: Horsepower - 2
rotor vs 3 rotor
Ken, my calculations indicate that a 2 rotor (13B) would need
to turn approx
8800 RPM to produce 250 HP at sea level. Now if you
use a turbocharger and
run modest boost say around 5 psi you would
still need to turn the engine
around 7200 rpm to get 250 HP. Getting
250 HP in an automobile
installation is much easier (you
have gears) than getting 250 HP with a
fixed pitch prop. Even Mazda
has reduced their initial HP claims (250HP) on
the Renesis to a more
realistic 237 (and even that is at its max rpm nearly
9000).
My
personal opinion is that if I were going to put a rotary in an RV-10, I
would go with the 3 rotor. You can get 250HP with a 3 rotor at less
than
6000 rpm and none of the complexities of turbochargers and at that
rpm the
rotor is quite happy (loafing really). Yes, they are more
expensive, but by
the time you turbocharged a 2 rotor properly, you would
have nearly the cost
of a 3 rotor.
My 0.02 worth on the
subject
Ed
Ed Anderson
Rv-6A N494BW Rotary
Powered
Matthews, NC
eanderson@carolina.rr.com
-----
Original Message -----
From: "Ken Peck" <kenbpeck@comcast.net>
To: "Rotary
motors in aircraft" <flyrotary@lancaironline.net>
Sent:
Friday, January 06, 2006 7:59 AM
Subject: [FlyRotary] Horsepower - 2 rotor
vs 3 rotor
> Having read a bunch of stuff on this forum and
other places, one question
> still nags in the back of my
mind.
>
> I'm building an RV-10, Vans recommends a Lycoming 540
producing 210 - 260
> HP. When considering the possibilities of a
Mazda rotary, obviously the
> ultra sexy choice is one of those 3 rotor
20b's. But in a recent post
> Bill Dube pointed to a Renesis RX8
13b 6 port engine on e-bay where the
> seller states
250HP.
>
> You know where I'm going....
>
> Can a 13b
built and configured to put out that HP in a RV-10 last, be
> happy,
etc.?
>
> --
> Homepage: http://www.flyrotary.com/
> Archive
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>
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