Prop size, where to start

[bj218]

I have a 92 Presuader, 218 w/454, rebulding at this time adding a procharger and some other goodies, looking at about 500HP, currently have a Merc Vengeance 21P 3 blade. Will I need to go to a 4 blade and what pitch? Looking for top end speed. Thanks Bj218

 

[boatman4021]

What gear ratio do you have? boatman

 

[bj218]

Prop size

Boatman, thanks for the reply, I have no idea, its a Bravo 1, how do I find out, I have a buddy who has a spare 26 pitch 3 blade, he will just trade me straight across. Thanks

 

[bigsbetter]

Most likely you've got a 1.5-1 ratio. We need to know where your rpm range of your engine is being built for. Barrow your buddys prop first and then go from there. That Vengance prop is certainly not a performance prop.