Aluminum Prop Differences

[Silent Player]

I'm looking at getting a new aluminum prop. Is there a drastic difference between the $99 prop and the $140 prop? Same diameter, same pitch, etc.

 

[hwsiii]

Re: Aluminum Prop Differences

Which exact props are you talking about.


H

 

[Silent Player]

Re: Aluminum Prop Differences

The props are all on iboats. I'm looking at the Solas Amita, QL by Volvo Penta, Solas Rubex, and Quicksilver Black Diamond.

I've heard good things about the Hustler Turning Point series, however I can't find any where that sells them for my outdrive (1989 OMC Cobra). Maybe I'm not looking hard enough?

 

[hwsiii]

Re: Aluminum Prop Differences

Re: Prop question
Hello HWSiii,

Sorry for the delay in responding. My direction has changed since my last email. I ended up putting smart tabs on my boat (wow, these things are amazing).

I originally thought I would need a 4 blade to get out of the hole quicker and keep a lower on plane speed, but now I think a 3 blade will work fine.

I also put my Viper 14 1/4 X 19 stainless prop on my boat. With this and my smart tabs, I'm definitely over revving the engine at 5100 rpm, at 37 mph.

Do I need to go to a 21 pitch, 3 blade prop? Also, on average (rough guess), how much top speed do you gain from moving 2 degrees pitch?

Thanks for you help and guidance,

Michel


Quote:
Originally Posted by hwsiii
Michel, I think you are on the right track I just need a little more information. Give me the RPM and speed numbers from 2,500 RPM to WOT in increments of 250 RPM.

H


Quote:
Originally Posted by Silent Player
Hello,

I figured I'd send you a private email, since you seem to be the authority on prop questions. Here's the specs on my boat:

1)1990 Chaparral 2050SL
2) LOA: 20' 3", 8' beam, 3,000 lbs.
3) Max hp is 275 hp. I couldn't find recommended
4) Normally 2 adults and 25 gals fuel (47 gal cap)
5) 17 deadrise
6) 1989 OMC Cobra 4.3
7) 160hp with 1.68 ratio
8) Recommended WOT 4200-4800
9) It does have a hydrofoil on there (early model)
10) Current prop: Bombardier aluminum 14 1/4 X 19 3 blade.
11) WOT is 4900 rpm, 39 mph gps with 2 adults and 25 gal fuel.
12) At sea level
13) Tuned up last year: New cap & rotor, plugs and wires, and carb rebuilt this spring. Compression is good on all cylinders.
14) Prop on boat has been on for 2 full seasons. It has a few ding and nicks on the leading edge, and the ends are a little worn. No vibration.

Goal for new prop: Boat currently has good hole shot. I've read your posts, and I think my boat is probably under powered. I'd like to get a 4 blade aluminum to cruise at a lower RPM. However, I feel that I may be able to get a slightly higher WOT speed (the last 300 rpms feel like they are over spinning the prop).

I'm looking at getting a 4 blade aluminum Solas Amita. It's a 14 1/4 X 19.

Just looking for your opinion.

Thanks,

Michel

OK let's take the SS Viper prop you have now and bring it to a prop shop and have them change the theoretical pitch on it by 2", that will bring your RPM down and your speed up.


H