77' searay 165hp WOT 3600rpms. Need new prop, what size?

[semo549]

Hey guys I have a 77' Searay srv-187 open bow. It has a mercruiser 165 on it. At WOT Im running 4200 rpms. with a normal 4 person load. I just added a hydrofoil to help out the crappy holeshot the boat had. I'm super happy with the foil, the holeshot is excellent. The problem is the hydrofoil knocked my WOT rpms down to 3600 with the same load. Pretty significant difference. I have a 3 blade 14.5" x 19pitch alum. prop on there now thats seen better days so I'm going to replace the prop anyways. What prop size should I go with to get my WOT rpms back?

Thanks for the imput

 

[junior1113]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

Hey guys I have a 77' Searay srv-187 open bow. It has a mercruiser 165 on it. At WOT Im running 4200 rpms. with a normal 4 person load. I just added a hydrofoil to help out the crappy holeshot the boat had. I'm super happy with the foil, the holeshot is excellent. The problem is the hydrofoil knocked my WOT rpms down to 3600 with the same load. Pretty significant difference. I have a 3 blade 14.5" x 19pitch alum. prop on there now thats seen better days so I'm going to replace the prop anyways. What prop size should I go with to get my WOT rpms back?

Thanks for the imput

a 17 p should get you up 300 or so. might not need foil. they really slow down a inboard. try a 15x17 with out foil. think youl be happy. that motor will perform best when wot rpm is close to 5600.

 

[hwsiii]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

Semo, junior is definitely right your rpm ought to be close to max with a 17" pitch at 4,600 RPM. It will help your hole shot a lot, get rid of the hydrofoil if you still feel the need to have something for stern lift buy some smart tabs sx they are only about $ 130. Here are my numbers.

Prop Picker

H

 

[steelespike]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

I think juniors 5600 is a miss print.I'm sure he intended 4,600.

 

[hwsiii]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

LOL I know he did too steele, that is why I didn't correct him.
Personally. I NEVER make a mistake.
UNLESS, I am breathing.


H

 

[semo549]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

17Pitch sounds good to me. However I don't think I ought to spin a 30 year old engine at 4600rpms. I want to be able to cruise at 3500 or so. The problem right now is that 3500 cruise rpms that I want is almost my WOT. So you think the 17" pitch will raise the WOT considerably? Should I keep the 14.5" diameter?

 

[hwsiii]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

Semo, get rid of the hydrafoil and you will be turning about 4,600 RPM and you can cruise at at about 3,500 RPM at a decent speed. If you need something to keep the stern up better buy trim tabs, The hydrafoil will lower your RPM too much at WOT.

H

 

[semo549]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

I just went ahead and purchased a Solex Rubex 3 blade ALum. 14.8 x 17P. Ill let you know how it works when it gets here. Thanks for the help guys

 

[hwsiii]

Re: 77' searay 165hp WOT 3600rpms. Need new prop, what size?

Please come back and post your WOT RPM and speed for my database.

H