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Stephen,
Impressive !!..................Love the V-8 sound...............I presume you have both
the "Ivo" 30 to 90 and 45 to 90 pitch blades..............With your hp I would also
presume the 45 to 90 are needed to hold back all that hp.................I also have the
electric "Ivo" (74", 30 to 90 pitch , 3 blades) for my estimated 180 hp 13B that has
yet to be run................Several of the Rotary group are currently flying both ahead
(and behind) the "Ivo" with varying blade lengths...............From your experience
with both pitch blades and with the ability to overpower them at will with shear brute
hp do you think that I will need the higher pitch 45 to 90 blades for my approx 180
hp 13B ??.................
Thanks,
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
-------------- Original message from stephen haas <admin@haaspowerair.com>: --------------
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Hi Guys... Just to add some data to the conversation.
I run a Ivo prop and switch between two different blade designs. Both are 76" dia and both are set up for inflight adjustability.
facts.
my ignition has 4400 rpm chips in them. redrive ratio is 1.43-1. I usually run 4400 engine rpm on take off and climb. this gives a prop rpm of 3076 and at 50f temp that works out to tip speed of 695.5 and .922 mach. Prop pulls real strong at this rpm, anything over that and it starts to lay down. It appears my Ivo is pretty effecient till about .94 or so. I have not had the balls to pull the chips out and take it to 1.0 mach but...
the motor was just under the chip rpm or about 4350 or so. temp was 26f, prop rpm around 3000, close to mach .93. The plane pulls good and as you can hear the motor makes alot more noise then the prop does. I have several guys tell me no way that I can run the prop that fast but proof is hard to deny.
Ben
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