Prop Article in Hot Boat

[SDLifesaver]

Does anybody have any insight to Bob Browns article this month about RPM's and prop size affecting top speed?

[A.SNEED]

IM PRETTY SURE RPM AND PROP SIZE HAVE SOMETHING TO DO WITH TOP END.

[sidewound]

Yeah, eek!
I think your right. Peace Man
Cesar

[Flashwave]

RPM and pitch have everything to do with top end. A prop turning a given RPM is only going to go so fast.
For instance, a 30 pitch prop will move forward 30" maximum for each full turn of the prop and no more. So at 1 RPM you move 30" at 2 RPM you move 60" at 3 RPM you move 90" and so on. If you have a 22 pitch prop, you would move 22" for each turn of the prop.
As you can see, adjusting your RPM higher will move the boat faster but the prop will still only move the boat forward 30" with each turn. Your just doing more turns in a minute to go faster.
In the real world, the prop experiences "slip". One could expect a 30 pitch prop to move a boat only 26" for each turn or 12% slip. A 22 pitch prop about 19" for each turn.
J