SoCal Jet Boats

Tech Talk => Jet Pumps => Topic started by: beerjet on October 24, 2009, 08:50:35 PM

Title: Berk vs jac
Post by: beerjet on October 24, 2009, 08:50:35 PM
So the subject of berk vs jac pops up AAAAALLLLLL the time.
A properly set/machined jacuzzi is "supposed" to run harder than a berk which is not the qualm, but rather the point.
Why is one better than the other in any form.

I've seen both stripped down and I have come to my own conclusions as to why, what and where....

What do you know  :sly:
Or opinion and why you crazy bastard !  :mad:

-beerjet-
Title: Re: Berk vs jac
Post by: GT Jets on October 24, 2009, 10:58:56 PM
So the subject of berk vs jac pops up AAAAALLLLLL the time.
A properly set/machined jacuzzi is "supposed" to run harder than a berk which is not the qualm, but rather the point.
Why is one better than the other in any form.

I've seen both stripped down and I have come to my own conclusions as to why, what and where....

What do you know  :sly:
Or opinion and why you crazy bastard !  :mad:

-beerjet-


Hmmmmmmmm

I like the Berkely for several reasons...But that is not what you're asking..........

The Berkeley Style pumps are by far more readily available in many forms....(Berkeley, Dominator, AT, GTH to name a few). So that being said, supply and demand comes into play, parts are less costly.

The Berkeley pumps perform very well in their stock form, in fact there really is not a whole lot to do to them to get them to work excellent, whereas the Cuzzi takes some know how and dough. (not DOH!)  ;D

I think the Berkeley's are tougher, I have one we passed golf ball sized gravel through and it is still useable. Try that with a Cuzzi.

"Jacuzzi" makes tubs and spas  :screwy:  "Berkeley" makes big ass irrigation pumps  8) (not related but so what)

What are you looking for? Permission to run a pool pump?    ;D

GT

Title: Re: Berk vs jac
Post by: beerjet on October 25, 2009, 07:59:52 AM
I agree with you glen about how the berk pretty much comes in ready to go and parts and what not.
Lets start to modify here and there.
First the impllor.
Cuzzi has 5 blades over Berks 4.
I remember the Cuzzi having a smaller exit side on the impellor which to me can only mean more pressure.
5 blades means more bite  :sly:
Yay or nay .....

-beerjet-
Title: Re: Berk vs jac
Post by: jet boat performance on October 25, 2009, 09:41:42 AM
I Love Jacuzzi Wj's there are VERY similar in design to Berk and infact (heard it here 1rst) with the new JBP WJ 4 blade impeller we hope to really prove this jets value . The WJ is strong , simple to work on and We have built dozens of Hard running boats with Dub J's over the years The Miller project has a "non energized" Wj in it which performs very well  ;)
Title: Re: Berk vs jac
Post by: Marcsrollin on October 25, 2009, 10:14:07 AM
I Love Jacuzzi Wj's there are VERY similar in design to Berk and infact (heard it here 1rst) with the new JBP WJ 4 blade impeller we hope to really prove this jets value . The WJ is strong , simple to work on and We have built dozens of Hard running boats with Dub J's over the years The Miller project has a "non energized" Wj in it which performs very well  ;)



Just out of curiosity , how much horse power are you throwing at them and what kind of speeds are you guys seeing?
Title: Re: Berk vs jac
Post by: Marcsrollin on October 25, 2009, 10:16:17 AM
CLASSIC COMEDY!!! You guys start talking about jacuzzi's and google puts a ad for hot tubs on the bottom of the page! ;D
Title: Re: Berk vs jac
Post by: Josh@JBP on October 29, 2009, 02:57:26 PM
I agree with you glen about how the berk pretty much comes in ready to go and parts and what not.
Lets start to modify here and there.
First the impllor.
Cuzzi has 5 blades over Berks 4.
I remember the Cuzzi having a smaller exit side on the impellor which to me can only mean more pressure.
5 blades means more bite  :sly:
Yay or nay .....

-beerjet-

In general a 5 blade impeller works best for hole shot and 4 blade impeller is better for max top end (you can liken these to propeller design ie 3 vs 2 blade).  There's a billet 5 blade impeller available for Berk but there again top speed is scrubbed off a bit in favor of low end performance.  Heres a curve, A Drake pump has a three blade impeller, and when Turbine was developing their SD-312 they also experimented with a 3 blade design and found it wouldn't produce acceptable PSI.

The look, shape, feel, inlet angle and approximate size of the intake up to the 6 3/4±" impeller mouth is uncanny between the two jets(STD berk and  jac WJ).

Compared to a Berkeley, the WJ impeller has a similar inlet blade angle.  The WJ blades are slightly longer, but flatten out and narrow slightly more toward the exit.   The flatter exit angle of the blades brings the outer shroud and the exit hub closer together, but the difference appears to be made up in overall larger exit diameters when compared to it's Berkeley equovolent.

The Bowl is the weakest link compared to a Berkeley, I don't have any actual numbers, but the bowl has less potential for volume.  The exit side of the Bowl is actually the true nozzle of the pump, often refered to as the cone.  Inside the cone is supposed to be a 1.5" round piece of aluminum with a bolt attaching it to the end of the bronze shaft support bushing.  The Round Aluminum piece subtracts area from the nozzle exit which is 3.350", giving it the same cross sectioninal area of a 3" nozzle.  It seems to be popular to remove this piece, but keep in mind, removing this piece makes the nozzle 20% large in area which is like changing a Berkeley nozzle insert from 3.125" to 3.49" nozzle insert.

In the end, in stock form they perform approximatley the same.  The Jacuzzi seems to require less maintance, no rope packing to leak or go bad, no gaskets (except for the intake), the plastic wear ring takes the brunt of the wear, Solid Bronze bowl support bushing rarely needs replacing or shows any real signs of wear, Thust bearing is sealed on both ends of shaft and doesn't require drive line yoke to seal front, inspection cover is large enough to throw a cat through and is build very strong....


I'm sure theres more, but i have to get some work done now

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