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  #1  
Old 11-17-2017, 11:45 AM
BLUEWAVERV7 BLUEWAVERV7 is offline
 
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Location: FLA
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Default Aluminum 3 Blade prop on RV7 with Lycoming 390

Has anyone used a 3 bladed aluminum constant speed prop off a arrow 200HP on a RV7A with a Lycoming 390 and how was the performance?
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  #2  
Old 11-17-2017, 03:14 PM
Canadian_JOY Canadian_JOY is offline
 
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Before looking at performance it may be wise to look at which 3-blade metal props, if any, have had vibration studies done on the IO-390. I think you may find the list of tested props is very short, thus you would end up being in uncharted waters with respect to understanding whether any RPM restrictions might apply.

The IO-390 is a fairly late-comer to the Vans aircraft but has been used extensively in the Glasair Sportsman. In that airframe there are no 3-blade metal props used with the IO-390. If you want a 3-blade then you're limited to composite props on that airframe.
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Old 11-17-2017, 05:32 PM
vic syracuse vic syracuse is offline
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Yes, can't emphasize Canadian Joy's comments enough. The metal props are really big tuning forks. It's just not worth putting it on your RV-14 when there are viable 3-blade composite props available. And the composite props available are tuned for the performance of the RV's. It's a win-win.

Vic
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Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
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  #4  
Old 11-17-2017, 08:00 PM
Captain Avgas Captain Avgas is offline
 
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The danger of using a composite prop on an RV7 is that you can end up with an aft CG problem and have seriously limited baggage capacity.
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  #5  
Old 11-18-2017, 08:06 PM
Lars Lars is offline
 
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Quote:
Originally Posted by Captain Avgas View Post
The danger of using a composite prop on an RV7 is that you can end up with an aft CG problem and have seriously limited baggage capacity.
Except that an IO-390 is heavy enough to cancel that out.
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  #6  
Old 11-19-2017, 07:06 AM
vic syracuse vic syracuse is offline
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Quote:
Originally Posted by Lars View Post
Except that an IO-390 is heavy enough to cancel that out.
That's correct with regards to the W&B.

Vic
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Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
EAA Homebuilt Council Chair/member EAA BOD
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www.Baselegaviation.com
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  #7  
Old 11-23-2017, 09:10 AM
BLUEWAVERV7 BLUEWAVERV7 is offline
 
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Thanks for the intell
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