Best Prop Performance 79 Merc 50 hp O.B.

[beck1967]

I'm looking for some info on what would give my 16' Grumman Renegade with a 50 hp mercury ob best performance. Hole shot and top end on mid size lakes. I have an aluminum 3 blade prop on there now(not sure what degree the blades are), i'm curious if a two blade prop would produce more torque? Also would installing a 4" setback on the transom to engine enhance the boats performance to a point that i would want to do it? Thanks Beck

 

[steelespike]

Re: Best Prop Performance 79 Merc 50 hp O.B.

Welcome,you should read the stickies at the top of the page.
Props are measured in inches Diameter X pitch ie: 13" X 15"
diameter is a product of the design not generally considered except in certain specific cases. 15" is the distance the prop moves in one revolution disregarding slip. Selecting a prop is like selecting a single gear in a car to do everything so there are comprimises.
The only way to properly select a prop we need your present prop size(usually on the barrel)max rpm and speed.Motor must be able to operate near the top of its rpm range.We need to know the year of your motor and details of what the boat is. A set back would help performance, how much would depend on your present setup.There are things you can do first that are less costly and can be effective. If you need a tach. The Tinytach is reasonable and easy to install or perhaps you could borrow a shop tach.GPS is best for speed.