Paul,
I'm wondering if P-porting the RX-8 would give the same overlap and
rough running at idle? I would think with the side exhaust this should
be less of a problem.
I would assume the P-port RX8 would give comparable power to your
engine, about 240 hp, no?
Regards,
Gordon.
PS: Thanks for the dry sump info.
-------------------------------------------
It might get 240 HP with those side exhaust ports.
I am not sure until someone dynos it.
Paul Lamar ...No rotor no motor.
Thanks, Paul.
What about the overlap and intake charge backing up? Would you guess the
P-port RX8 might reduce that problem to some extent?
Regards,
Gordon.
I think it would be about the same as the old side intake port
and p port exhaust. It would be an interesting exercise
that is for sure. You might be able to do away with one
or two of these sealing rings on the side of the RX8 rotor for
less friction.
--
Paul Lamar ...No rotor no motor.
Thanks, Paul.
That's good news.
The reason I ask is because I would like to run an Ellison carb, not fuel
injection. So the slide throttle will not work.
http://www.ellison-fluid-systems.com/article/notaposa/notaposa.htm
I had no idea about the sealing rings you mentioned, and would probably just
leave things stock.
If it's possible to get about 240 hp naturally aspirated with a P-port RX-8,
I would probably do that as a first step, then experiment with supercharging
later.
Even so, you would have an engine weight of a four-cylinder Lycoming, with
the power approaching that of a six. The Pitts S2C that Aviat sells comes
with a 250 hp AEIO-540 that weighs a lot more than the 240 hp P-Port RX8
that we are talking about.
Regards,
Gordon.
I did not say it would get 240 HP with one Ellison carb :)
I assumed you were using a slide throttle.
Try two smaller Ellison carbs :) One for each runner
like the Weber.
Klaus is doing away with his Ellison and is now using EFI and is
going to a rotating slide throttle instead. Something like this
but with a larger diameter disk or smaller holes.
People are not entirely happy with Ellisons.
Paul Lamar ...No rotor no motor.
Paul,
I agree EFI is great, but I have doubts that the auto-based components could
withstand the high g-forces of acro. The injectors for example look like
pretty fragile devices. And would they even open in a high negative G? Or
they might squirt fuel when they're not supposed to in high positive G.
That's why I like the simplicity of a carb. Float carbs won't work for
inverted flight, so that leaves Ellison. I haven't heard much bad about
them. I think he's been plugging away on those for 20 years and they work
fine on aerobatic planes.
I think you're right that with one carb you will lose some power compared to
your setup with the Weber where the air has a straight shot down each
barrel. With a single carb you would have to have a log plenum and a right
angle turn for the air to go down the runners, although I would put trumpet
horns on the runners.
Two carbs would be better for power but then you have to worry about
synching those carbs, more complex linkage, more weight etc. I might just
take the small loss of power with one carb. Heck even 220 hp would be
outstanding if you could keep the overall weight to a minimum.
Regards,
Gordon.
Sounds like the old SU days :)
Paul Lamar
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