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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