Jacuzzi 12 WJ/B

[BrendellaJet]

I just bought an 18ft 77 Brendella with this pump in it. Was this standard issue? Can any one tell me if this pump is any good? I dont know anything about he internal set up. How much for a rebuild kit? I build all my own engines, so I dont think the pump would be a problem for me. There is currently nothing wrong with it. Pulls hard, very mild 454 and the boat does just over 60 mph per my brothers wave runner speedo(i know its not a gps, but it cant be that far off) Should I spend money on maximizing the setup with my 454? or do I need a different pump. Can I get a place diverter for it? I would like this boat to do 70 mph. I can handle the motor mods, but what needs to be done to the pump? Thanks for your wisdom!

[jacuzer]

Welcome to the other side!
The W pump you have is not a bad pump despite what many think. The main drawback is if you have to replace the major parts (imp, bowl, shaft etc...) buying new will cost you plenty.
To make it perform you HAVE to have the pump blueprinted because the stock impeller is so terrible. If yours has not been done you can see what I mean by reaching in there and feeling the leading edge of the blades. (motor not running please!) The stock impeller was just downright inefficient and they never thought to improve it. Another drawback is that the plastic wear ring wears quickly if you boat in dirty water. Mine has lasted many years with care.
The next thing you need to look at is the intake.
If you remove the stock grate you are left with a nasty little step on the biting edge of the intake. If you are planning to get to 70mph you might want to look at removing the intake and having a shoe & ride plate installed (which takes care of the nasty little step). I welded a peice into my step and detailed it out real nice and wished ever since I would have gone with the shoe.
You will be able to fit a Place Diverter on with the adapter that they sell or have your bowl modified for a berkely style nozzle.
Sounds like your pump is in reasonable shape already, don't let anybody talk you into an energizer kit! Those are good for Jacuzzi "Y" pumps.
PS don't buy the Seloc jet drive manual for this since it doesn't touch on "W" pumps.
Hope this helps,
Kevin

[beached1]

Jacuzer has some great advice. The only thing I could add is that a Place Diverter will make a great improvement. But only if it's done right. Every other mixed flow pump is setup to where the steering nozzle IS the nozzle also. In a WJ, the nozzle is part of the casting in the bowl. You'll need to have the nozzle cut off and the bowl bored out to match the place adapter. Otherwise, you will have a two nozzles in line which would rob you of thrust and HP. I sent my WJ to MPD and had these changes made along with having the impeller reworked. The difference was amazing and worth the $. Jacuzzi WJ's are a good if they are reworked with the things mentioned above.

[Hondo468]

I have a 74 hondo with a 12wj/B pump, 468ci BBC, edelbrock tunnelram with 2 holly 600's
I'm only able to get 4800rpm out of it. I read that with a modified BBC you need to run a C or a C/D impeller. Any advice would be appreciated.
Thanks,
Alan
[ August 09, 2002, 10:02 AM: Message edited by: Hondo468 ]

[Hondo468]

[ August 07, 2002, 11:14 AM: Message edited by: Hondo468 ]

[wsuwrhr]

I modified the shit out of my WJ, I love making underdog parts run good. I made a 17-4 shaft, added a Berk A impeller, and modified the bowl to adapt a G bowl style place diverter. Runs good so far. I started on a bowl stuffer but I haven't taken the bowl back out to finish it. I second the vote for Jack at MPD, he will talk to you all day on the phone, or in his shop to help you out or answer any questions you may have. I bought all the parts from him and machined eyerything myself.
Brian

[wsuwrhr]

If you are happy with it, and it ain't broke, DON'T FIX IT. laughs
Brian

[rssfla]

I would love to see some pics of these mods if you guys have them!

[ChetCapoli]

Originally posted by jacuzer
Another drawback is that the plastic wear ring wears quickly if you boat in dirty water.
Kevin
I wonder if slowy read this part, he's seen similar wear rings go over sandbars without a problem. :D
CHET

[mrgoslow]

brtendella, i have a 19' vee with a wj. when i put the boat together i ran the wj stock with the exception of ditching the plastic wear ring and running bronze impregnated werar ring than any machine shop thats worth a crap should be able to do for you if you have some pump knowledge. if there is not one near you that will do this, i can recommend one in corpus christi, tx that did mine. at this point the boat ran its best of 70.8 at 5050rpms. hp is 482 hp at 5500 on dyno, i just cant remember at 5000. prob 430ish
on to the good news. with no engine changes, ive installed a dominator bowl and berkeley b imp and now run a best of 80.1 at 5350-5400. i like that speed to rpm ratio. maybe its that big gaping hole of an intake matches the flow characteristics of the dom bowl. i dont know but i like it.

[BrendellaJet]

:D
Tat should play out pretty interesting then with my stage 3 bowl. Maybe Ill have to buy ATMs kit afterall?

[Chris J]

If you go with a diverter. You can cut off the cone and grind it down flat with the housing. You will have about a 1/4 larger diameter at the housing than the nozzle so boring shouldn't be necessary (this can easily be done with hand tools if you don't have access to a mill). You will also want to chuck the center reducer. Make sure you plug the old tapped hole to keep water out of the grease. I retapped mine with a 1/4" NPT and installed a 1/4" pipe plug.
Diverter and reworked impeller should give you the most bang for your buck, and its bolt on stuff. The pumps are extremely easy to rebuild. Don't know that they could be designed any better from a rebuild stand point. You may need a press but other than that its a snap.
Oh ya, I got all new seals, gaskets, bearings and great advice from Duane. He also tossed in a free tube of grease before he gave me the bill. (I thought dam how much are these parts going cost). Not to worry bill was under $250. REX has bolt on diverters in stock.

[BrendellaJet]

Well, Ive already had mine blueprinted by Jack at MPD. It will be interesting to see how it performs. If Im not happy with the speed, Ill likely try out the AT energizer kit...
I wonder if the bowl for the energizer kits is made specially to fit the WJ, or if they are all the same, and you just need to modify the shaft for the new impeller?

[mrgoslow]

the wj uses different size bolts (bigger) than a dom/berk. i turned my dom bowl and re-drilled/tapped. the shaft has to be turned down to accept imp and bowl.

[napabob]

BrendellaJet,
I just installed a Place diverter on my Jacuzzi 12WJ/B. I haven't done any improvements like cutting off the 'extra nozzel' as discribed by 'daps', but it will be an option to think about.
I purchased the diverter from Jim Brock and he also mentioned the 'cutting off' of the nozzel, this might become a winter improvement job.
http://www.hotboatpics.com/pics/data/1/6782IM000228-med.JPG
http://www.hotboatpics.com/pics/data/1/6782IM000226-med.JPG

[BrendellaJet]

Here is what I am working with:
MPD flowed bowl with nozzle removed and berk adapter added:
http://www.***boat.com/image_center/data/500/212100_0281-med.JPG
MPD blueprinted intake with shoe and rideplate, Jeff Bennett keel and bottom blueprinting:
http://www.***boat.com/image_center/data/520/212100_0600-med.JPG
MPD blueprinted impeller:
http://www.***boat.com/image_center/data/500/212WJ_Imp_fr_finished-med.jpg
We will see how it does early next year.

[Anthony75]

I have a 19" Anthony bubbledeck 12wj/b with a stage 3 blueprint by Jack. Shoe, rideplate, droop, diverter, custom loader and 2" setback. Before the pump mods I was doing 67.5. With pump mods I am doing 77.7 on gps with no engine changes.

[BrendellaJet]

Anthony75-what kind of power are you running. Thats an impressive gain. Sounds like its pretty equivalent to the energizer kit...

[Anthony75]

I am running an Olds. It spins to 5000 rpm. My best guess at horsepower is 475