Prop selection

[$SeaRay$]

Hi all. I have a 1973 Sea Ray SRV 190 with a 351WINDSOR. Went from a Pre Alpha outdrive to a Alpha One. Used old propeller from Pre Alpha. Boat would do about 50 mph with old outdrive. New one is a different ratio and will only get up to 35 mph. I'm unsure of current prop pitch. Anyone know how to calculate what prop I need to get me close to what I had before?

 

[Bondo]

New one is a different ratio

Ayuh,...... Welcome Aboard,...... No answers til We know what the new ratio is,......

Movin' this to the prop forum,......

 

[achris]

Need to know the old ratio, the new ratio and the current prop pitch.

'Gets you in the ball park' formula is ...

New ratio/old ratio x old pitch = new pitch

Once you have the new pitch you put it on and see how it goes. Tweak it from there.

Chris........