Re: Prop information

Melvyn Hiscock · Post by **Melvyn Hiscock** » Sat Dec 27, 2003 8:46 am

'I need some help.

Very soon I am going to have to decide on a prop for the Rearwin
Cloudster. Normally this would be nice and easy as I would just look
up which one is needed and go buy it. The Sensenich website suggests
a 78/57 or 78/59 for the Ken Royce motor but I have a 145 Warner. So,
thinking that a F24 with a 145 Warner might be about the same size
and performance as a Cloudster I looked up which prop would be used
for that and it shows 86/67 or 86/69 .

What I need to know is where I can find the parameters for working
out which prop I should have. According to another listing I have
lurking in all my paperwork the Cloudster could have a min of 78in
and a max of 86 in and that is with the Ken Royce.

When I got my airplane it had no motor but had been using a Hamilton
Standard GA of 84in. I decided not to go with this as I want a wood
prop for weight considerations and because if i do ding the prop I
want that to break and not the motor!

So, how do I work out the diameter I need and the pitch using the
aircraft weight, performance an known RPM? Is there a book I can read
or does anyone here have a magic formula.

Over to you guys and thanks in advance.

Melvyn Hiscock'

cliffmccluney@webtv.net · Sat Dec 27, 2003 9:14 am

'Melvin, there is a little book entitled "Propeller Making for the
Amateur" which goes into all of that. It is by Eric Clutton, 913 Cedar
Lane, Tullahoma, TN. 37388. In 1993 it cost $7.00

I had a Cessna Airmaster prop on my Waco RNF (145 Warner) once, and it
was an 82RA81. It was a bit too much pitch for the slow biplane but was
probably just right for a faster machine.

Regards,

Cliff McCluney
Kerens, TX.
PT-26'