Effects of 3 blade to 2 blade

[NJCinMN]

Just out of curiosity...
what are the effects on rpms if you switched from a 3 blade 17p to a 2 blade prop of the same pitch?

or say you went from a 3 blade 17p to a 2 blade 15p?

does the general increase of 200 rpm per inch still apply?

 

[steelespike]

Re: Effects of 3 blade to 2 blade

When changing more than pitch all bets are off.especially when details of
manufacturer,material and design details. 200 rpm per inch is a very broad rule of thumb that generally applies to larger applications.
You could say that same brand,same design adding blades tends to lower
max rpm slightly simply due to the added resistance.