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  #1  
Old 12-05-2018, 06:59 AM
Cwood2000 Cwood2000 is offline
 
Join Date: Jun 2012
Location: Tallahassee, fl
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Default Prop size

Anyone run a 74 or 75” prop on a 14 tail dragger?
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  #2  
Old 12-05-2018, 06:29 PM
Discus2b Discus2b is online now
 
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Location: Willis Gliderport
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Default

Order the 74”.
The 72” was needed to satisfy the drop test.
Don’t drop it.
R
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  #3  
Old 12-06-2018, 04:29 AM
Cwood2000 Cwood2000 is offline
 
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Ha Ha, thanks!
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  #4  
Old 12-06-2018, 10:07 AM
Don E Don E is offline
 
Join Date: Aug 2016
Location: West Chester, PA
Posts: 81
Default I chose the 72”

Flying my phase I now behind the recommended 72” prop and loving the performance.
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  #5  
Old 12-07-2018, 11:26 AM
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mulde35d mulde35d is offline
 
Join Date: Dec 2017
Location: Williamsburg, VA
Posts: 175
Default My 2 cents

Just my 2 cents, but as always think about your mission. If you compare the same brand and type of prop in a 72" version vs 74" with the same Max RPM on the same plane then aerodynamically the 72" prop should have a higher top speed vs the 74" prop which should have a shorter takeoff distance and faster acceleration. Their is a lot more to it than just that, but that breaks it down to the basic question of which one better suits your mission.
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  #6  
Old 12-08-2018, 04:00 AM
Cwood2000 Cwood2000 is offline
 
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Location: Tallahassee, fl
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Thanks for the info, I'm having the prop overhauled
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  #7  
Old 12-08-2018, 07:57 AM
rv7charlie rv7charlie is offline
 
Join Date: May 2006
Location: Pocahontas MS
Posts: 3,863
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There are 76" dia props running without issue on -7s, -7As, & at least one -8 powered by rotary engines. Surely the dia won't be an issue on a -14.

As to speed, the larger dia will definitely improve takeoff performance. And IIRC, when you run the numbers on rpm/dia/airspeed, you have to get a fair amount faster than 200 mph before getting hurt by a 76" prop at Lyc rpms. If it's c/s & you're running down at 2400-2500, like most seem to do these days, the larger dia should have unmeasurable negative effect at speed. For perspective, a Cessna T-210 cruises at roughly RV-speed (faster at O2 altitudes), and runs an 80"+ diameter prop at 2600 rpm.
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  #8  
Old 12-10-2018, 05:03 AM
Cwood2000 Cwood2000 is offline
 
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Location: Tallahassee, fl
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Thanks for the detail, the prop is in the shop being overhauled as we type.
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