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Thanks Lynn
I would like to get 200hp at 7500RPM, With a gross weight
of 2300lbs on floats & a cruise speed of about 120mph
it's not like an RV. My plan is a plugs up position with a 3
stage Weaver dry sump pump and a 14 quart oil tank. I have a
90 13b NA (9.7:1 rotors) Mazdatrix street port template, 3GM
evaporator cores in series & RX7 oil cooler (2 if
needed), RWS 2.85:1 re-drive, EM2 & EC2 with an IVO
84" controllable propeller. Is 200HP a pipe dream?
Georges B.
It is possible that you could get very close
to 200 HP with a street port. The last conversations I had
with the two great engine builders I know was that the E
production engines (13B treet ported two 38MM chokes) were
producing 229HP and 231 HP, but at close to 9,000. In reading
about Dave Lemons engines (also E production) he said he could
not get used to shifting after the 10,000 RPM light comes on.
These are in very fast cars, and in most cases faster than
mine (GT-3 12As). Google Dave Lemon. These are running a
limited (by rules) street port.
Turning that big a prop 2,631 RPM even with
no pitch is perhaps hopefull.
The airboat people tend to very low pitch
large diameter props with wide blades. They also use 550 cubic
inch 350 HP engines. The latest gag is two props counter
rotating at differing RPM. That so they can load the boat
and leave from the dry grass into the water and not need a
loading ramp. Check with Ken Weller on that float plane stuff.
He uses a 100 HP nitrous shot (available at any hot rod shop)
to explode out of the water. He has the extra fuel required
figured out and shuts off the trailing ignition during the
shot to prevent detonation. Remember the definition of
detonation? Very clever.
If you were looking for 190 HP with a 50HP
nitrous shot on top of that to pop up I would say no problem.
I have no feel for the drag of floats vice a displacement
hull. Sounds like it would be
less.
I am down to 6 quarts in the small holding
tank. Tall and small diameter. It was a new fire extinguisher
bottle. Clean and light. If you don't already own it, I would
skip the weaver brothers pump. I have one. It is a gear and
idler type and cannot pull much of a vacuum and unless new
inside cannot produce top pressure. It just has very little
displacement. A gearotor (ring and rotor) type is what I use
now. The old round style Peterson is fine. the newer square
bodied Peterson is junk. The pressure section splits open
along the bolt holes. Only a college graduate would build a
square pressure vessel. My current pump is the Moroso
with the Ford pressure section (bigger rotors) 1 1/8" instead
of 7/8" (I think). Peterson does have a selection of Gilmer
belt pulleys at a good price. The belts are cheap through any
power transmission store. A friend just paid me another Moroso
pump that I built for a Datsun years back for building him a
rotary he had damaged. So now I have a spare Moroso
pump.
Unless there is a real clearance problem, I
would avoid the plugs up thing. It adds several engineering
problems to a very busy program. You can move the filter to a
remote location with no problem. Planes with that layout tend
to land on roads more than others.
Lynn E. Hanover
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