The idea is that this thread could become sticky, and act as a resource for information about props. It seems like there are a lot of people asking about props for different applications, different watersports, amounts of ballast, etc. and the same information gets repeated a lot.

So please keep responses limited to propeller-specific discussions, and tell us ALL of the following:

  • Boat Info:
  • Year
  • Make
  • Model
  • Length

  • Drivetrain Info:
  • Engine / HP
  • Transmission (ratio, e.g. 1:1)
  • Prop Specs: part # and/or Diameter, Pitch, Blades, Cup

  • Performance / Usage
  • WOT RPM
  • What do you use the boat for?
  • How much ballast, if any?
  • Difference between loaded / unloaded if applicable?


Did I miss anything? Is that too much information?

I'll put mine out there in any case:

Boat:
1989 Supra Bravura 21'

Engine:
PCM 351 / GT-40 / 310hp
1.23:1 transmission
Acme 1868 Prop: 12.5x14.25 4-blade .075 cup

Performance / Usage:
4700 RPM WOT with no ballast / no passengers. 41 mph.
Various watersports: skiing, wakeskating, some surfing, lots of just cruising.
Boat performs okay with 1500lbs ballast or ~10 people which is all you can fit anyway.
Prop could/should be lower pitch if I ran it loaded all the time, but I am more often with 1-2 people than loaded.

Other props I've tried:
Acme 422 ran only 4300 RPM WOT (12.5x15.5 4-bld .105 cup)
Acme 654 ran about 4500 RPM WOT (12.5x15 4-bld .105 cup)