need a 17" by i think 14 1/4 prop for alpha 1, where to find one

[crazygn]

I have a 21 right now and need a 17", anyone know who might sell a cheap new or used prop. 3 or 4 blade

Also whats a good brand

 

[Dave.Mishchenko]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

I have a 21 right now and need a 17", anyone know who might sell a cheap new or used prop. 3 or 4 blade

Also whats a good brand

You can get them right here on iboats.com - http://boatpropellers.iboats.com/. My last 2 have come from here and the price was very good. I've last used a Solas Rubex 4 blade and it's worked quite well. You'll see a significant change in WOT RPM changing from 21 to 17. Have you done any speed tests to determine that a 17" won't cause the motor to over-rev?

 

[dirtdiver]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

How do you know you need a 17? I went from a 19 to a 17 and noticed a big difference. Iboats does have a good selection and when I bought mine, shipping was free...

 

[crazygn]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

i run 4300 rpm now. I want to get in the power band of the cam to make more power. Cam power band is 2000- to 6500. Like to see around 5000 rpm

 

[crazygn]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

heres a question

Say my engine makes 275 hp at 4300 rpm with a 21 prop. And the engine makes 320 hp at 5000 rpm, if i lower the prop to a 17" to run at 5000 the boat should have more top speed right.

just making sure iam right with all this, not a boat guy till this year

 

[steelespike]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

have you read the stickies at the top of the page and the helps on the prop store page. Prop pitch numbers 17" and 19" mean that disregarding slip a prop moves 17"
or 19" forward in one revolution.In order for a 17 to be faster it needs to be able to make up the distance with more rpm. the actual results will vary based on the prop, gear ratio, boat weight and style. Also there are bow lifting props and stern lifting props ss and al props for low to mid range performance and for top end performance. The various brands and models have different features.
Prop selection is usually a compromise.A prop should be selected to put the motor within its designed rpm range at wot(wide open throttle.
In a car a motor might run at 5,000 for a few seconds occasionally.
In your I/O you might run it for several minutes or maybe more if a speed freak everytime you are out.I think you can see this could add up over time.

 

[crazygn]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

Thanks for the info, i'll look now at the stickys up top. My big problem is the boat seems rare or something because i can find any specs on the thing like weight and stock prop and so on. Its a larson senza 1989 210 , with a alpha one SE drive and a heads cam 350. Big prob is the cam in it makes power in high rpms so i hoped to make more power and go faster if i could rev it some more

My prop now is a mich wheel SS 21 x 14.25 and the boat runs at 4300 WOT. I just dont see the cam making good power at 4300 butr could be wrong.

cam is a comp marine cam 12-244-4

498-500 lift
234-244 dur

 

[sethjon]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

Changing 4" at one time is too much. Try a 19". Also, are you looking for hoe shot because you'll defintely one with that radical change.

 

[crazygn]

Re: need a 17" by i think 14 1/4 prop for alpha 1, where to find one

Not really, looking to get the rpm's up to high more in where the engine makes its power for more top end speed. It really needs a cam change but thats at the end of the year to lower peek power around 4800-5000

The stuff ive seen says a stock 350 's max rpm should be 4600-5000 and the mag 350 is 5200 rpm