Propellers are a specialist subject and a full understanding needs a propeller specialist. Whilst Beta Marine has many years of experience learning which propeller normally goes with which engine, we can give only give you general guidance, please note that we are not propeller specialists.
Propellers are normally measured in two dimensions:
- The actual diameter (frequently measured in inches).
- The pitch – assuming the blade is set at an angle, then if you followed this angle through one revolution and measured the distance between the starting and finishing point, you will have moved forward the measurement called the pitch.
The propeller size is often limited by the actual space available when trying to fit it in position. These size limitations are frequently the diameter, due to the space limitations between the position of the propeller shaft and the underside of the hull. This can be compensated for by changing the pitch, but there are limitations. For further information on propellers, please look at the individual manufacturer’s websites for information:
A general guidance for propeller dimensions in inches – based upon a 3 blade RH (right hand) rotation and a 2:1 reduction ratio.
|Engine||Beta 14||Beta 16||Beta 20||Beta 25||Beta 30||Beta 38|
|Propeller||12" x 8"||12" x 8"||13" x 8"||14" x 8"||15" x 9"||17" x 10"|
|Engine||Beta 43||Beta 50||Beta 60||Beta 75||Beta 90||Beta 105|
|Propeller||18" x 12"||19" x 12"||20" x 12"||20" x 14"||Please Ask||Please Ask|
Propeller Information Downloads
This is a very basic explanation that hopefully explains that you need expert advice from a propeller specialist. If you have any questions please do not hesitate to contact us.
Beta Marine Propeller Information Sheet – Propeller Information Sheet.
Sailing Today Propeller Article – Propeller Information Article.
Seamanship Motorsailing Propeller Article – Propeller Information Article.