Props

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smurfsideresort

Cadet
Joined
May 12, 2003
Messages
11
Great deal on 14 1/4 x 23 Ballistic SS but does anyone have any idea if I will be able to turn it. I currently have a 14 1/2 x 24 Raker SS, 1987 225 Johnson, 19' J-Craft ski-boat (flat bottom). The raker has vent holes and gets me up and out 90% of the time 62MPH, 5200RPM. Lately I've been loading it up with 5 tubes and Kids and the 5th tube seems to have put me over the limit for planing except with a circle start. I've tried a 14 x 22 4 blade Piranha and a 14 X 20 4 blade Piranha but it seems without the vent holes I can't quickly spin them. Any one tried one of these Ballistic props.
 
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Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Props

I know Rakers are good, especially the 24, but that ones great. Youre at 3% slip or less. 5200 is lugging that motor badly but the slip is unbelievable!<br /><br />As far as the prop goes, if you're spinning a 24 Raker where you want to, I'm sure you can spin a 23 Bull-istic. Why not just try it and see what happens?
 
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walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Props

Bull-istic, as DH says...is a hard pulling prop, but so is the Raker. I've used both...I prefer the Raker, but I can tell you the ballistic will blow-out before the raker-Ballistic doesn't have as much bow-lift either.
 
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smurfsideresort

Cadet
Joined
May 12, 2003
Messages
11
Re: Props

Can you send me the formula you used for slip. I'm guessing its RPM x gear ratio(which I don't know) x pitch x 60 (minutes in an hour) / 12 (inches in foot) / 5280 (feet in a mile) <br /><br />eg 5200 * .5 x 24 x 60 / 12 / 5280 = 59<br /><br />Just trying to figure out what increase in RPM I need in order to keep the 62 MPH as I go down in pitch.<br /><br />I'm pretty happy with the Raker just wondering if there was a better prop that would maintain the top-end and give me a little more oomf out of the hole. Any experience, anyone has with 4 blade, 5 blade, torque-shift etc. would be appreciated.
 
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Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Props

We rarely -- if ever -- go down in pitch to gain rpms. We'd rather work with the set up. <br /><br />If your at only 5200 now we really doubt that any decent 4 or 5 blade prop will be satisfactory.
 
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smurfsideresort

Cadet
Joined
May 12, 2003
Messages
11
Re: Props

Interesting, I thought as I go down in pitch say from 24 to 23 the RPM will go up approx 200. So if I spin a 24 @ 5200 and a 23 @ 5400 then what is the effect on top speed. I know the 23 should give a better hole shot and at the same RPM the 24 will go faster. Don't know what I could do to the set-up, motor is mounted fairly high already. Could probably put on a jack plate, but I am currently at odds as the boat was built with a flat bottom and 2 keels to keep as much of the back end in the water to prevent a skier from pulling it around which goes against making it fast. Maybe if the 24 was shaved to 14 inches instead of 14 1/2, I could get the revs up.
 
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shep70057

Petty Officer 2nd Class
Joined
Oct 16, 2003
Messages
115
Re: Props

I'm all for having a 4 blade prop. It has a lot of advantages over the 3 blade but most importantly is how it LIFTS a load. By reducing the surface area of a prop you will gain RPM's. How much .... I've been told and experienced that 75RPM's per 1/4 inch. Pitch is also increased when going down in pitch and vice versa. By going down in pitch you will loose some speed, but that is all things remaining the same... as far as slip. If your slip numbers go down, your speed may actually increase.
 
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