I really don't know. My guess is take off at 300 HP and
back off to 200 HP for cruise. Then you have the cooling
problem. 300 HP takes a heap of cooling.
--
Paul Lamar ...No rotor no motor.
My 2-cents worth on this point:
- Getting 300hp on the prop shaft out of a mechanically supercharged engine
means developing 320-330 hp (we never managed to get more than 300hp out of
a 2-rotor... but we also never tried!... blowing up engines gets expensive
very quickly!)
- While it is possible to boost a 2-rotor to 330 hp, it is much harder to
keep it out of detonation with "regular" gas (i.e. non-racing fuel). It
takes a lot of boost to get that much power (typically >60 inches MAP), so I
would insist on very efficient intercooling to keep intake air temperature
below 50°C [122 F] if possible, certainly below 60°C [140 F].
- Next, water cooling problems: you must avoid localized boiling spots.
It's generally OK if it's only a short duration power surge (like in drag
racing), but longer than that, things can get out of control real quickly.
- Metal apex seals won't last long. 3mm ceramic seals are probably a must.
- Last thing: be prepared to open up the block and change parts quite often
during tuning! Also, fuel consumption will be unacceptable for cruise above
200-220hp.
My opinion: unpractical and unwise for any other purpose than racing...
cars or aircraft. If you need that much power, go with a 3-rotor, you will
have none of the above-mentioned headaches!
Francois
Hi Francois,
Thanks for those intake air temperature numbers. Been looking for that data
for a long time. Back in the 1940's 50's & 60's large radial aircraft engines, both
supercharged and turbo charged, routinely used anti detonation fluid for take off.
It is also common practice at Reno air racing. I suggest anybody looking for above
300 HP for take off out of a turbo charged two rotor think about using it.
Also read this C&D article on how PTP obtained 360 HP out of a turbo
charged RX8 engine with ten to one compression ratio rotors using intake
air triggered anti detonation fluid.
http://www.rotaryeng.net/Turbo-RX8a.jpg
http://www.rotaryeng.net/Turbo-RX8b.jpg
Here is a power to weight ratio chart I have been working on. Still a work
in progress. For normally aspirated only and no psru.
Paul Lamar ...No rotor no motor.
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