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Old 10-17-2005, 09:06 AM
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jrjohn
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Default RE: Extreme Flight 87" Yak 54 - Build & Fly


ORIGINAL: wgeffon


ORIGINAL: sillyness

Why is everyone ignoring me? Do I anger you?

LOL.. Missed your question.
(was it about the motor placement?)

3" standoffs is what I am using with the DA. That seems to get the CG very close. You can move the cowl back a little to have the motor to appear to stick out further forward. That will actually help with getting more air into the cowl and help with prop efficiency.
There was a big discussion about this in the QQ 85" Yak thread.
Wayne, I've followed the QQ thread as well, I'm still wondering about the prop efficiency issue. I have no concrete evidence telling me that spacing the prop out further will have any appreciable effect. Have you compared your plane, which I assume the prop is spaced 15/16 from the cowl (correct??), to a plane with the book set up of 7/16? If so, what is your evaluation?

I'm not opposed to putting more space between my cowl and prop, However I'm running the stock muffler and I'll have to cut the cowl so the muffler will clear. If necessary, I'll Add 1/4 inch to the standoffs and machine a 1/4 prop spacer.

john