I am going to repower my 2000 380Da...

[Burntundra]

I am going to repower my 2000 380Da at the beginning of next month. I am not the first or second owner and have only owned the boar for 2 years. I lost the starboard engine early last year. Since I am unsure of the pedigree, and based on the corrosion found in the starboard, I am replacing both long blocks to be safe.

I am curious about the correct prop size and pitch for my boat. I know an ex-Sea Ray mechanic who stated that Sea Ray traditionally oversized these props for some reason. I am not very knowledgeable about propping a boat and am not sure where to start. For instance, How do I know what is installed on my boat now? Do any of you know how to determine the most efficient size and pitch for optimum fuel burn at different cruise rpm?

[wingless]

The four blade 21" diameter propellers on my 2000 380DA w/ the 454 MAG MPI Horizon engines has 22" pitch, measured as 21.980" on starboard and as 21.998" on port.

My understanding is the diameter / pitch are selected to ensure that wide open throttle (WOT) falls into the engine's specified sweet spot range, 4,600 - 5,000 rpm for this engine.

My experience is these propellers are correct for this engine / boat so the RPM is correct.

Different propeller settings might be required w/ different horsepower / weight engines, that might have a different WOT sweet spot.

[Pigpen]

After rebuilding one of my 480s after dropping an exhaust valve seat, I took 2 inches out of the stock 24x27 props.