The potential of some of the marine outboards is
awesome, mainly for their power to weight ratios.

Take a look at the cruise fuel burn of a two stroke vs. a rotary,

calculate the extra fuel load (and operating cost), and see if the two
stroke still makes sense.

Jon Lauter
Rotary Power Marine Corporation

Context is everything.  Remember that I was talking about a time to climb
racer.  You get no extra points for burning less fuel.  Cruise?   In a
racer?

And yes, Abel may get 800 HP from the 13B but it's in a seven second drag
racer.   I am rarely accused of being too conservative but you would not get
me in an airplane with a 13B pumped up to 800 hp :-)

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

The time to climb record is 58 seconds. Will you trust a 600 HP 13B for 58 seconds?

Actually Abel does dozens of runs without working on the engine.
Try that with a 1300 CC piston engine pumped up to 800 HP.
Heck almost any piston engine less than 5000 CC's.

BTW here is a picture of Abel's intake plumbing. Do you think Able was
looking for high velocity in the intake runners? :-)>

Paul Lamar

Come to think about it the loads on the rotor bearings may be lower at
high boost pressures and high RPM. Normally aspirated the rotor bearing
loads are a minimum at 6000 RPM and they rise rapidly from there
due to the centrifugal force of the rotor weight. If you pump up
the engine the net rotor bearing loads may be less as the pressure
cancels the centrifugal forces at some e-shaft angles.
The engine is structurally extremely robust. I see no reason
why it should not tolerate 800 HP.

The only limitation I can see to getting a bunch of HP for less
than one minute is the bearing loads and perhaps the loads on
the phasing gear. Higher oil pressure should help the bearing loads.
Able told me a couple of years ago that at the time the limiting factor
was the bearings. Cooling should not be that tough of a problem. 

I think if you can get 800 HP for eight seconds and have the bearings 
live I see no problem at all getting 800 HP for one minute. Jim Mederer 
has hundreds of hours at the 300 HP per rotor level on the dyno. 
400 HP per rotor is not that big a jump.

Allan Tolle did 58 seconds to 3000 feet with nitrous and 350 HP in the 13B RV4.
And that was with a fixed pitch prop no less.

Since the time to climb is almost directly proportional to power
to weight ratio a 600 HP 13B RV4 ought to put the record beyond 
any other intermittent internal combustion engine powered airplane.
Other than another wankel rotary that is.

Too bad they don't have the time to climb contest at Sun & Fun anymore.

Paul Lamar
 
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