Overdrive Ratio?

[corleone17]

How do you know how much overdrive to run? Is there as good rule of thumb? HP? Boat? Ect?

[burtandnancy]

Well, its a function of many things; what do you want your boat to do, pull skiers, cruise or lots of top end? Then, is it a fast hull such as a Rayson, Schiada, Hallett etc? And finally how much horsepower and torque do you have. In my past ski race days as I got more experienced, got into faster boats, we ended up with 50% overdrive. You've got to find your goal and go from there...

[corleone17]

The boat is a 21' Daycruiser with a Merlin 509, Approx 580-600 H.P. Unk? Torque? I am looking for top end..i dont do any skiing..i am currently running a 12X14 Menkins...I am unaware of my current overdrive ratio? I have a Casale split case, with a powerglide trans.. Thanks for the reply...

[Stab-n-Steer]

corleone,
What kind of RPM are you running? It looks like you need more prop just based on your data... Hopefully V-Drive Tom will jump in and set us straight.
S&S
[This message has been edited by Stab-n-Steer (edited June 26, 2002).]

[V-Drive Tom]

Corleone17, As BURT said we needed to know what you want out of the boat. Sense your not skiing with it you should be running a 2-blade prop. As S+S said we need to know what RPM your engine is reaching now. Is your motor reaching top RPM too quickly? What makes you think it isn't correct now? TOM..