Prop Suggestion

[DFW Miles]

Alright gentlemen, here's what I've got. I'm looking for prop suggestions (pitch only, I've got a model that I am satisfied with) for a 1988 Celebrity 190V. I'm currently maxing out at 5100 RPM with a 14.5X19P with what I consider an anverage load, 300 RPM above my engine's max RPM rating. I'm thinking that I should jump up to a 21 pitch prop to put me at the top of the recommended range. I already have a 14.5X17P Stainless prop that is a monster for pulling a tube or whatever so I'm looking for something that will be the most efficient for just cruising around the lake.

-I just want to get the most efficient all around prop for cruising the lake.
-Current prop is a stainless steel Power Tech class E three blade 14.5X19P
-Just ran 40 MPH at 5100RPM WOT with what I consider an average load for me (wife and two boys and some gear).
-1988 4.3 Mercruiser Alpha One 175 HP (unsure what the gear ratio is, I'm assuming whatever is standard) RPM range is 4400-4800.
-1988 Celebrity 190V 19' 2350 Lbs dry weight.

So....... do you think that I should switch to a 21 pitch or stick with what I've got? Thanks

 

[Texasmark]

Re: Prop Suggestion

The higher the pitch, the harder it is to maintain the attitude of the boat in conditions other than WOT. A couple of days ago I posted about my boat and my props. All the same mfgr and everything else but pitch. The pitches are 17,21, and 24. I posted what my boat did with the 3 props.

300 rpm's over on a 5100 spin is only 5.9% and your tach could be off that far. If you want the best efficiency pull up some boat performance curves on here or the www and for any planing hull, the best efficiency and reasonable speed is just on plane, where the boat comes out of the hole, the bow drops about as low as it is at WOT and the engine is loafing along. The engine is usually well into the power curve, torque is up, efficiency is up, the water drag is at it's lowest as is the hull's resistance.

That's about it. Keep what you have.

Mark