Performance numbers

[FishStretcher]

I just raised my motor one hole and I am considering going to a 13.25 x 15P 4 blade Solas Amita 4 to see if I can redline my motor. I will know soon.

[Fr. Frank]

Let us know as soon as you have the data.

[FishStretcher]

Will do. Java prop predicts 2-3% better efficiency. Hoping for 35MPH.

[FishStretcher]

If I like the 15p, then I might finally go stainless. Maybe 3 blade, depending on how I feel about the amount of stern lift. I feel like the 15p in aluminum might be a little too little pitch, but I will have 2 weeks on the water after the 4th of July to A/B compare. I guess I should bolt on the paddle wheel for a test. GPS might not be accurate with wind and tide.

[FishStretcher]

Originally Posted by Fr. Frank

Let us know as soon as you have the data.

Raising the motor one hole got me a little. Maybe a knot of speed, but only if I trim the motor to a point where it starts to ventilate a bit, I think. When I did that, I could jump on the throttle and slip or ventilate to get to 5900 RPM occasionally.
But the extra speed came at the same 5600 RPMs, steady state, withou crazy trim- so that's good. And the cable steering is better (lighter). But I need a hydraulic helm.

I will check throttle adjustment tomorrow. If that is correct then I will bolt on the 15 pitch. If not, then I will adjust it then try a top speed run again.

[FishStretcher]

Update- the 13 x 15 4 blade pulls to redline, and when trimmed the same (nearly blowing out in turns) is a few tenths of a knot faster before redline. Top speed is really splitting hairs. But it gets there a lot faster and it is a little less trim sensitive. I love the holeshot. Trolling is a little more adjustable, too.

9% slip calculated for this 13 x 15" pitch four blade prop at 6000 RPM at 29.3 knots over ground
15% slip for the 12.75 x 17" pitch 4 blade prop turning 5600 RPM at 29.1 knots over ground

Originally Posted by FishStretcher

Raising the motor one hole got me a little. Maybe a knot of speed, but only if I trim the motor to a point where it starts to ventilate a bit, I think. When I did that, I could jump on the throttle and slip or ventilate to get to 5900 RPM occasionally.
But the extra speed came at the same 5600 RPMs, steady state, withou crazy trim- so that's good. And the cable steering is better (lighter). But I need a hydraulic helm.

I will check throttle adjustment tomorrow. If that is correct then I will bolt on the 15 pitch. If not, then I will adjust it then try a top speed run again.