Prop substitutions?

[Nexxus6]

Hello all,
I'm new here from Maine and I have a quetion about propeller substitutions. This winter I plan on building a F4U from a kit (Great Planes Kits) and it advises a 2 bladed prop, an 11 X 6. I would like to replace it with a 3 bladed prop for historical accuracy. What specs should I be looking at if this is possible. Any advice is most welcome. Thanks.

[Nexxus6]

FYI From www.Bolly.com

MULTI BLADE PROPS

There is no exact formula for selecting a 3 or 4 blade prop in comparison to a 2 blade prop, pitch remains much the same but the diameter must decrease. A 4 blade 11 x 7 is not double the load of a 2 blade 11 x 7.


Selecting the correct 3 or 4 blade prop is very much dependent on the brand and type of prop.

Most nylon type 3 blade props are very inefficient to the point where (for a given engine size), the diameter reduction makes for a drastic reduction of performance. For example, a .60 size engine using a 2 blade 12 x 6 will need to go to a 3 blade 10 x 6 for similar engine rpm.... clearly not acceptable, especially where vertical performance (= diameter) is a criteria.

A well designed (narrow bladed) CRE or GRE prop can be used at a diameter between 90 to 95% of the equivalent 2 blade prop. For example, in the Bolly range the 11.25 x 6.5, 3 blader would be the equivalent of a 12 x 6, 2 blade prop.

[Chip Morrison]

Looks like you solved your problem.

Cheers,

Chip