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Hi All,
Is anyone on the list using the stock throttle body with the EC2? I've been stripping mine down to repair the fire damage, and it looks like there's a lot on it that isn't needed for aviation operation. In fact, it looks like I could mill away the top 50% of the TB and not impair function at all - except making the intake ducting a little more complex. One thing I'm working on is a simplified version of the EdDIE manifold, with the secondary bores feeding only the secondary ports - rather than just increasing the airflow to a common plenum. Perhaps, it will be easier to get a low speed idle that way. I'm also sticking with the original 6 port manifold base; it's just too tempting to use the secondary power port valve actuator holes for the secondary injectors.
What I'm looking for is more information about the upper butterfly assembly in the secondary path. It appears to be a delay mechanism to keep the secondaries from effectively opening during low speed WOT conditions. Can I safety remove it? It seems as though it's not buying me anything in an aviation environment.
Thanks,
Dale R.
COZY MkIV-R #1254
(It is now 20:20 AZ time (23:20 EDT)
Subject: [FlyRotary]
Re: idle speeds (prop stopped flight)
I
had a cruise prop (80 inch pitch) sensenich metal prop on the 6A. When I was
doing engine off glide testing, some thought I would do better with engine
stopped rather than turning. Really had to slow way down to get prop to stop. Could
not measure the difference in glide engine stopped or windmilling. Really had
to go fast, over a hundred to get it going again!
Bernie
Kerr, painting the 9A waiting to get rotary back from Bruce T at SnF
A stopped prop is in a complete stall
condition, and would be expected to provide less drag than one that is turning
at an RPM of incipient stall. There will be some RPM for a given pitch
and touchdown speed that will provide the most drag. We just have to
figure out what that is.
Landing speed in Kts times 100 gives you
ft/min. Pitch divided by 12 gives you ft/min per revolution of the prop
for neutral thrust (approx.). So my 85 pitch prop at 70 kt landing speed
is neutral at 1000 RPM. So maybe the max drag point is somewhere
around 650 RPM (mas o menos 100). Just a guess. Someone less propeller-design
challenged than I may have a better answer.
Al
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