Hello all, I am converting my single shaft to a duel shaft model. Any suggestions for motors and props to get the 24 sec speed. I am unsure which way to go. Thanks, J
I would say something close to what I am running on my Des Moines would likely get you close. I have two Johnson 550 motors to use on my Battlers BG 500 gearboxes that go out to a set of 1 1/2" props with a 25 pitch to the blades. I was running slow with that set up and well the props got the pitch tweaked a bit to get to the 23 sec speed the Des Moines is supposed to run. Truth is I may now be a hair fast. I do suggest you listen for other suggestions before you commit.
What is making you change? My understanding is you want a single screw and the double rudders, it turns better.
One reason to change is reliability. 2 shafts gives you redundancy in case of moss, or a thrown dog bone, or some other brand of failure. That being said, I personally would probably go 1 shaft or all three powered. I don't think I'd only power the 2 outer shafts, but that's just me.
Not sure I understand why you wouldn't power the outer two. With full propwash going over each rudder, the boat should turn better. Powering all three would be difficult without small motors I think. Besides, having two powered screws decreases the time it takes to get up to speed or stop, doesn't it? J
Fine, except that in a turn you DON'T have full propwash going over each rudder (assuming all are in the correct spots, correct size, shape, & balance). On the outside of a turn (away from the direction the rudders are turned), about 1/2 or more of the propwash will blow right past the rudder, not striking it, when only outboard props are driven. Drive the center prop only, & no matter which way you turn, you have a rudder fully over the driven prop. JM
"Fine, except that in a turn you DON'T have full propwash going over each rudder (assuming all are in the correct spots, correct size, shape, & balance). On the outside of a turn (away from the direction the rudders are turned), about 1/2 or more of the propwash will blow right past the rudder, not striking it, when only outboard props are driven. Drive the center prop only, & no matter which way you turn, you have a rudder fully over the driven prop." Quoted for truth. Outer shafts only will hurt your turning, not help it.
