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O.S. .91II props

Old 04-13-2010, 11:36 AM
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Fear2722
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Default O.S. .91II props

Hey all-

I've got an O.S. .91 FS II in my P-51 .60 arf from Top-Flite. I've currently got a 14x6 on it. The plane pulls well, but seems slow... Can I prop this differently for better speed? What props are recommended? Also thought about throwing a 1.20 in it, just haven't decided yet. Focusing on props just now.

Thanks
Old 04-13-2010, 11:45 AM
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MinnFlyer
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Default RE: O.S. .91II props

Get a Graupner 13.5x8

Hobby Lobby has them
Old 04-13-2010, 11:46 AM
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Default RE: O.S. .91II props

Suggested Prop(s): Stunt planes: 11x11-12, 12x10-12, 13x9
Scale models: 13.5x8, 14x7, 15x6, 16x6, (12x8 & 12.5x7-3 blade)
Old 04-13-2010, 02:25 PM
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ChuckW
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Default RE: O.S. .91II props


ORIGINAL: MinnFlyer

Get a Graupner 13.5x8

Hobby Lobby has them
Agreed. Excellent prop for that engine. Their 14x7 works well too. APC 14x8 is another option.
Old 04-13-2010, 03:44 PM
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Default RE: O.S. .91II props

Just start testing bigger pitched props, even the 10s. I don't have the P-51 but I have several of the .91s for pattern planes and use the 15X4 APC to slow them down and add some torque. I get a kick out of using the Grapuner 14X7 three blade. Sort of like adding disc breaks on my planes. Theres a big selection of props that your engine will use and testing is fun!!
Old 04-15-2010, 08:17 PM
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lilhachet
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Default RE: O.S. .91II props

you should be useing a 15/6-15/8 on a 91. or for a little speed, try a 14/10.
Old 04-16-2010, 02:03 PM
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Default RE: O.S. .91II props

OS recommends nothing bigger than a 14" prop
Old 04-16-2010, 02:28 PM
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Default RE: O.S. .91II props

I ran a 15x6 on one for a while. I did not like it at all. Dropping down to a 14x8 and a 14x7 made it a completely different engine.
Old 04-17-2010, 04:38 PM
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Default RE: O.S. .91II props

Hi!
A 15x4 or 15x6 will not work! They have too large diameter.
A 14x6 APC or RAM is what I would try!
Old 04-17-2010, 08:01 PM
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Default RE: O.S. .91II props


ORIGINAL: jaka

Hi!
A 15x4 or 15x6 will not work! They have too large diameter.
A 14x6 APC or RAM is what I would try!
Oh no, my planes are going to fall from the sky!!!!!!!!!!!!!!!!! Prop testing is the only way anyone is ever going to know what they like. Chuck didn't like the 15X6 but I liked them for the plane I was using them on, I like the 15X4 a lot better.

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