SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: crusader1983 on January 26, 2009, 10:46:55 AM
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Hi everyone,
I am new to this site and jet boating all together. A year ago I purchased a 1983 21ft open bow Crusader jetboat with a 454 and a berkley jet. I am in the works rebuilding the motor and I have heard people talking about a cavitation reducer that gets you out of the hole and planning alot quicker. Can anyone tell me more on this or have any ideas of how I can get a better start. I take the boat to Havasu and would like to beat my friend and his wakeboard boat. More info on the boat no ride plate and no loader. Thanks for the help guys.
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Welcome to the site. Reducing cavitation is an honorable goal but don't get the cart before the horse. What you listed as what you don't have are excellent starting points to add first. Reducing cavitation would include an overall check of the pump tolerances and maybe adding a stuffer plate. Back in my racing days we spent hundreds of hours with a dye grinder smoothing and blending the pump internals to reduce cavitation and yes it was a good thing to do but the gains are very minimal but necessary if your racing. Some guys who want more hole shot now are adding inducers (think of like adding a jet ski impeller in front of the standard impeller) but again this is generally racing stuff. Also remember that the ride-plate, shoe and loader work hand-in-hand so if you go that way do it all together so you can tune the ride and performance as a unit. Otherwise you may be adding more to the overall cost by having to re-tune each time you add something else. Stuffers and the internal work can then be done as "phase 2".
nozzle reducing shims and the like will come as you gain experience and keep adding HP to the engine. Have fun and stay in touch with us here on the site.
PS we all like to see pictures.
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Thank you for all the advice I will look into all of those ideas. And granted I am not racing I am a bit of a throttle junkie that is very competitive and hate loosing to a wakeboard hence why my previous motor let go but I figure it was on its way out anyway. So i figure since I am doing the motor might as well look into the pump. Plus I had a shop work on my exhaust flaps and the very next trip the motor overheated and let go. It had no previous heating issues. So that is a reason that I am taking a more hands on approach. I will be posting so pics as soon as I get home. Thanks guys.
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welcome to the site crusader! i think wizard got it on point for the cavitation reducer. i know that it sounds like an inexspensive way to get some bottom end power, but like he said, soon as you start getting some power from the motor, you will need to make adjustmants to the inducer.
ask tom about his product, he can probably tell you about it best:
http://www.jetboatperformance.biz/pages/inducers.html
i'm sure people on the site run it and will have more feedback.
good luck and can't wait to see some pics ;D
-Justin
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There are many guys here who can point you in the right direction but you can't beet talking to Jack McClure at MPD, Costa Mesa for assistance and real quality work in the pump department. He would prefer to do the work for you but he will tell you what your priorities should be when upgrading the performance of your Berkley.
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what is MPD?
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Marine Performance Designs...off of monrovia and i velive 16th or 17th in costa mesa/newport beach ca
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Hi everyone,
I am new to this site and jet boating all together. A year ago I purchased a 1983 21ft open bow Crusader jetboat with a 454 and a berkley jet. I am in the works rebuilding the motor and I have heard people talking about a cavitation reducer that gets you out of the hole and planning alot quicker. Can anyone tell me more on this or have any ideas of how I can get a better start. I take the boat to Havasu and would like to beat my friend and his wakeboard boat. More info on the boat no ride plate and no loader. Thanks for the help guys.
I would love to throw some advice your way, but you did not give much info., do you have a Place Diverter or other nozzle adjusting device, this will help lower your overall planing speed and possibly get you a mile or two top end MPH...When you say "cavitation reducer" is it cavitating? Could just be a loose pump (loose meaning worn out)..
Throw a few more tidbits out there, may be a little problem, or no problem at all...RPM?, Top speed?, blah blah blah,... ;D
Welcome to the goofiness :D
GT
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Welcome to the wonderful world of SCJB ;D
There is a good chance that your boat will not launch like a wake boat because of the of the size of your boat (21') and the fact that the wake boat is probably direct drive with a prop.
But the good thing is if you can catch him off guard you can soak him down with a precisely aimed nozzle. ;D
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Honestly in YOUR particular situation an inducer (cav reducer) is a waste of good money , requires precision shaft machining and a little more work than a basic jet rebuild/overhaul and in the "Bang for Buck" department IMO you will not likely see a significant improvement given your application . Much better to put your money and effort into a quality AA impleller (lift and hole shot /big boat) and a Place Diverter or Turbine trim (if you dont already have one ) Call Post or PM if you need help Tom