Another forgotten aircraft configuration that worked was the Vought V-173
Flying Pancake--otherwise known as Zimmer's Skimmer.  The thing flew very
well and the configuration would be very easy to do in composite.  They
never tried to lift off vertically but it could have if it had enough power.
As it was, it had pretty amazing short field performance.

The guys at Racing Beat say they're not going to build aluminum housings for
the Renesis engine.  What do the power curves for the 13B engine look like
and what does it weigh?  The Renesis engine, unblown, puts out as much
horsepower as the turbocharged 13B, but it runs at higher RPM than the 13B.
Apparently the Renesis engine has much better ports, what other improvements
are there?  I'm trying to figure out which engine would be better for a
helicopter.

Steve Brazil

The weight is about the same. Except for the RX8 water pump which
is a pound or two lighter. The big drawback to the RX8 is the side
exhaust ports so that is why R.B. does not want to build alloy end housings
for the RX8 motor. The alloy end housings might melt.

I am building a P-port intake RX8 engine as we speak for purposes
of finding out just how much the side exhaust ports hurt.
I would not mess with anything other than a p-port as it gives
more power at 7500 RPM than an RX8 engine does at 8500 RPM.
It will also give a lot more power at 8500 RPM than an RX8 engine.
In the 300 HP ball park. I just added a Mazda tech paper pdf to the
ACRE web site for free download on the p-port 4 rotor LeMans engine.

http://www.rotaryeng.net/

It had 172 HP per rotor at 9000 RPM NA. That is 345 HP of course
for a two rotor.

Larry is machining (soon :) a mechanical fuel injection which
I intend trying on the RX8 p-port dyno engine.

Since we have successfully welded in a stainless steel tube to the
steel liner on a 2nd gen engine intake side it might be possible to do the
same thing to an RX8 rotor housing on the exhaust port side converting
it to a p-port.

Paul Lamar ...No rotor no motor.


Paul,

You said something about autorotation with that VTOL Canard--I don't think
so.  I was reading somewhere that co-axial rotors have a problem in
autorotation.  Remember that in autorotation you reverse the direction of
flow through the rotor disk.  On top of that, forward flight, to some
degree, is needed and the drag would be terrible on your concept flying
belly first.  This is an ideal candidate for a ballistic chute and two
larger engines going into one transmission.

You also asked something about what to do in the event of electrical
failure.  I don't think anything electrical would be required in the control
system, at least it shouldn't be in aircraft that we fly.  On the VTOL
aircraft we're talking about, the aircraft should be designed to be
controllable in airplane mode for a forced landing if the chute doesn't
work.  I try to not get too far from concepts that work.  Money is not
unlimited and not many of us can afford to experiment with manned vehicles
that don't have a high probability of success.  If you want to see an
example of a magnificent aircraft that could have been, check this out:

http://brumbyhelicopters.com.au/_avideo/windstar2.wmv


There was nothing deficient about this aircraft; I think the reason that it
didn't become available was that there was just too much to get past the
FAA.  Actually, a turbocharged 20B engine would have probably worked well in
this helicopter.  My plan is to start with a Rotorway Exec and develop a
drive, engine and transmission, that will weigh less than the current system
and be able to deliver 160 horsepower to the rotor when the rotor is in the
low end of the green arc at 7000 feet, standard day.  I would also like to
see a 2000 hour TBO.  If I do this successfully, I've got plans for my own
helicopter.

Steve Brazil


A ballistic chute certainly would not hurt. Perhaps it will auto rotate
in a side slip. 2000 hours TBO is no problem. I would still use
a p-port. You don't have to use all the power.