Prop manufacturer and pitch recommendation

[kaliona]

My current prop has been on the boat since I bought it used. I rarely run it at WOT. I usually cruise out to my fishing spot at about 30 mph and anchor most of the day, or troll at very low speeds. Have used it a couple seasons to pull kids in a tube on kneeboard, and the fastest I would pull them is about 15 mph.

Just recently started reading this forum and the importance of having a prop to match mfr's recommended WOT range. And I've found out over the last few times I've taken the boat out that at WOT, I'm at least 300 rpm under the recommended range.

I would like the recommendation of the many prop experts here to help me chose a brand and the proper pitch for my boat.

1978 Caravelle, 17' bowrider, 82" beam, 2000 lbs dry weight
used mainly for fishing
12 degree deadrise
1978 GM Inline 6, 165 hp motor, drive gear ratio 1.65:1
Max RPM at WOT: 3900-4300
current prop: 15 1/2", 19 pitch aluminum, good shape, minor nicks

Normally 2 people on board with 14 gallons gas, 2 batteries, fishing gear, 2 ice chests. My WOT RPM is approx 3600 RPMs, GPS speed approx 36 mph, elevation: sea level and up to 550 ft.

I'm thinking I have to go to a 17 pitch to get me in the proper WOT RPM range. I checked the iBoats store and there are several to choose from. Any advice/recommendations on brand and pitch would be appreciated.
Lastly, how would this change in pitch affect my cruising speed and fuel usage?

 

[steelespike]

Re: Prop manufacturer and pitch recommendation

Its my feeling your 165 hp should be able to reach rpm with a 19.
You might be sure the motor is in tip top tune,Throttle plates opening all the way,Bottom clean and smooth.Boat responds to trim.A 17 will give you some rpm
"up to 400"It will improve hole shot, but you may lose speed.

 

[kaliona]

Re: Prop manufacturer and pitch recommendation

I feel the motor is in tip top shape and it does respond to trim adjustments. As far as the bottom is concerned, the previous owner painted it with what looks like anti foul paint. Its not smooth and I've always wanted to remove it. Just never got around to it. Maybe that paint is affecting the boat's performance. So is it still a bad idea to get a 17 pitch prop?

 

[kaliona]

Re: Prop manufacturer and pitch recommendation

I'm going to go with either a 17 or 18 pitch prop. Not sure yet. Does brand matter? Does anyone have input on quality between Michigan, Quicksilver, or Solas?

 

[Slip Away]

Re: Prop manufacturer and pitch recommendation

I would recommend a Michigan Match 15-1/2 x 18 part # 031052. You will get your RPM, holeshot and virtually unnoticeable decrease in top speed.

 

[sublauxation]

Re: Prop manufacturer and pitch recommendation

You menion the anti-fouling paint not being smooth, not sure how bad yours' is but I've read various articles that say having a little texture on the bottom of the hull is actually better than being perfectly smooth. I don't know how much difference it will make but dropping pitch will give more RPM and may slow your troll down a bit too...which is usually a good thing.

 

[sethjon]

Re: Prop manufacturer and pitch recommendation

I'm going to go with either a 17 or 18 pitch prop. Not sure yet. Does brand matter? Does anyone have input on quality between Michigan, Quicksilver, or Solas?

All 3 are good props.