Prop size am I being told correctly?

[5teve]

Hi guys, just looking for a set of 4 blade props over here in Oz, 2120 4S spec. I am being told that they are square geometry props so a 21x20 will be the same as a 20x21 performance wise. I ask as there are no 21x20's available so need to be cast, and at $5500 for a pair, are not very cheap! I can get a set of used 2021's for $2500 delivered...

So is the advise given correct?

Steve

 

[CLB]

Prop sizing is a bit of a black art, but I have heard that changing diameter has a similar effect to a corresponding change in pitch. I would guess, and it is only that, that you would get very similar performance, probably near enough not to notice the difference, but maybe not exactly the same. The rouble is, it is an expensive gamble, unless you could sell them on, if no good, and get your money back.

 

[omega2]

email Paul Williams, www.clementsmarine.co.uk

 

[oldgit]

Can recommend that you contact Michigan Wheel directly or via your local agent, lead/shipping times do affect price.
Despite being made in USA and shipped here, their prices including all taxes were considerably less when compared to the smaller bespoke UK outfits.
The UK agent was extremely helpful and responded quickly to queries via email.