What size prop ?

That's a bit tough, try a 10x6 I run that on my sig kougar with an FP40 Ian

That's way too much prop for that engine. Try a 10 x 4. When you ask what size prop you need, you should specify what type of plane/flying you'll be doing with it.

In general terms: GIVEN THE SAME RPM: A small diameter/high pitch prop will give more speed and less acelleration/pull. It's like high gear in a car. A large diameter/low pitch prop will give more acelleration/pull. and less speed. It's like low gear in a car. Dr.1 Driver "There's a Hun in the sun!"

Depends on the application :-( If you have noise sensitive site I would try either 10x7 or 11x6 and work from there. I run 11x6 props on my SC40s.

We're gonna try it in a Weston Magnum just to see if it's got enough power to fly it at a reasonable speed.

cheers, Len

----- Original Message ----- From: "Len Cuff" Newsgroups: rec.models.rc.air Sent: Sunday, September 12, 2004 2:35 PM Subject: Re: What size prop ?

In that that case you need a screamer :-) start on 10x7 then if you can handle the noise 9x8

10x6 top flite wood

earl

Sad to reply to my own post but -- APART from the Weston engine (!) what would anyone suggest in the 40-46 range which would at least get this thing off the ground?

cheers, Len

Irvine mkIII .39 with a 9x6 APC prop. More power than most sport 40's and a lot lighter too.

Eric

Oops! Getting my Magnums and Cougars mixed up!

An Irvine .53 with pipe would suit the Magnum better.

Webra speed 50 mk

Had the offer of a Mk3 Irvine 40 and the guy reckons it'll tear round with it.

Any thoughts?

cheers, Len

size 9 boot and a drop kick?

10X5 or 11X4. It is about the same power as a .32 ball bearing motor but lower RPMs. Don't expect much more than 11-12k..

GMS .47 will turn a 10X6 at around 14k. Pipe it and you will get over 15k.

Webra Speed 50 is lighter and more power still, but costs more.

The FP ain't gonna cut it. I suggest a Webra Speed .50, Jett, or Nelson. Small diameter/high pitch prop.

Dr.1 Driver "There's a Hun in the sun!"

APC 12.25 x 3.75! GREAT prop on a .40!

That is a great prop if all you want to do is hover. You must not know what this plane is. It is a swept wing, high speed plane and the prop you suggest would be a great disappointment on it.

Not on the FP. It won't turn it. Dr.1 Driver "There's a Hun in the sun!"