Replacing Jacuzzi 12JY Jet Drive
MCir...@bigfoot.com
I have a 21 ft Kona Day Cruiser with a Jacuzzi 12JY jet. It has seen
better days. I would like some opinions on what the best long term cost
effective performance options I have. 1. Rebuild the pump $700.00. But
never have a diverter. 2. Replace the back end with a American Turbine
Energizer Kit $1400.00. 3. Replace the complete drive (+suction) with a
proven Berkeley 12JG rebuilt for $1400.00. + $300.00 for the glass work.
I am concerned about my performance, because the pumps are so
different. The 12JY are an Open Impeller, Axial flow, while the Berk and
AMT are the more common Mixed flow pump. I really like the boat and
intend to keep it for many years, (5)at least. I would like to get up in
the mid 60's one day. I don't want a weird setup, or one that I can not
easily add or update with easy to find parts.
Any input would be great!!! Good Job, Thanks for your opinion.
Please post to this board so others with the Jacuzzi 12JY can benefit.
Mike
You can check it out at http://www.xoom.com/hotboats/
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MCir...@bigfoot.com wrote:
>
> I have a 21 ft Kona Day Cruiser with a Jacuzzi 12JY jet. It has seen
> better days. I would like some opinions on what the best long term cost
> effective performance options I have. 1. Rebuild the pump $700.00. But
> never have a diverter. 2. Replace the back end with a American Turbine
> Energizer Kit $1400.00. 3. Replace the complete drive (+suction) with a
> proven Berkeley 12JG rebuilt for $1400.00. + $300.00 for the glass work.
>
> I am concerned about my performance, because the pumps are so
> different. The 12JY are an Open Impeller, Axial flow, while the Berk and
> AMT are the more common Mixed flow pump. I really like the boat and
> intend to keep it for many years, (5)at least. I would like to get up in
> the mid 60's one day. I don't want a weird setup, or one that I can not
> easily add or update with easy to find parts.
>
> Any input would be great!!! Good Job, Thanks for your opinion.
>
> Please post to this board so others with the Jacuzzi 12JY can benefit.
>
> Mike
> You can check it out at http://www.xoom.com/hotboats/
>
Hi Mike,
Kona made nice solid boats that will last a long time. Not a bad
idea
to invest some money in it if you plan to keep it a while. Sounds like
you already know that the Jacuzzi "Y" pump is low on the prefered list
of jet drives. I see 5-10 people a year at my shop asking the same
questions. Here's how I answer.
1) The "Y" pump was never great, even brand new. It can,
however, be
made better than new with careful reconditioning. This would be
difficult for you to do at home since the stainless impeller often needs
welding and always need machining for improved performance. If you do
attempt the job, be aware that the wear ring rarely needs replacement,
the tailshaft area often needs hard chroming and the mechanical seal is
fragile and easily damaged during dis-assembly. Bottom line here is that
for the smallest investment this pump can be better than new, but will
never perform like a Berkeley/Turbine/Dominator mixed flow pump.
2) I've installed both Am.Turb and Dominator conversion kits in
"Y"
pumps and I find lots of little (and sometimes very big) problems with
these kits. If you go this route check everything very carefully. Make
sure the new wear ring ends up concentric to the shaft and that the bowl
fits tightly on it's locating ring. Errors here are quite distructive. I
saw a few problems with the Turbine steering nozzle and related parts
that conviced me not to use them any more. Both Turbine and Dominator do
not hard anodize their aluminum parts, but powder coat the raw aluminum
instead. Corrosion follows shortly. The impellers are prepped ok in some
areas and very poorly in others. It's hard to believe these factories
have never seen a race prepped impeller to learn what the proper shape
is! Bottom line here is that the performance gains for the money spent
are pretty good. I'd choose the Dominator kit, and check everything very
carefully. Down the road you could add a Place Diverter and get the
impeller blueprinted.
3) Rip the "Y" pump out and install a good used Berkeley.
Wouldn't you
know it, the most expensive option is the best option. This is such a
major operation though, with so many complications (like relocating the
engine), that I'd still recommend #2. Good luck with your project.
I checked out your web site Mike. Good job. Looks like a lot of
work
went into it. BUT WHAT'S THAT PROP DRIVEN HYDRO DOING AS THE
WALLPAPER???THAT'S GOT TO GO!!! :-) :-) If you need pictures of jet
boats that HAUL ASS let me know. I can email you a few .jpg's.
Jack
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Mcir...@bigfoot.com
In article <34792E...@pacbell.net>,
I'll change that Hydro ASAP, promise!
What is the fastest American Jet boat now?
Mike
Jack McClure
Mcir...@bigfoot.com wrote:
>
<snip>
>
> I'll change that Hydro ASAP, promise!
> What is the fastest American Jet boat now?
>
> Mike
>
The Blown Fuel Jet "Going Places" ran 170.58mph in 1993. I've
heard
that others have been in the 170's, but I don't know any specifics. The
data collection & hardware specialist (J. Bennett) on Ken Zeal's BFJ in
1994 told me recently that they had some 170+ runs and he felt 190 was
attainable. However that boat was destoyed at Wichita in mid 94. That
class of drag jets is dying out here in Calif. The NJBA doesn't have any
blown fuel classes (jet, flat, hydro), I think, for insurance reasons.
They rarely have blown alcohol, for the same reasons I suppose. The top
NJBA classes are Blown Gas Hydro/Flat/Jet. They still put on an exciting
(and safer) show, IMO.
The go-fast setup for a BFJ is so different from all the other
classes
of racing jets that I never got real interested in it. Almost nothing
that a BFJ does would work with other jets, and vice-versa. My interests
are mainly naturally-aspirated classes (UBFJ, PGJ, CJ, MJ) and the ET
brackets. I find it more interesting to see how fast you can go with
restricted equipment rules. That's also very challanging and lot's
cheaper for the guys doing it.
I don't have the NJBA record list at hand but I'll see if I can
find it
and post it later. There are other drag-boat organizations running jets
(SDBA-Texas area, CSDBA-Missouri area, etc) that have their own records.
Maybe members of these other groups will post their achievements. Jet
classes only for me, thanks. :-)
Last thing Mike - - When thinking jets, think less about speed
and more
about quickness, ET (elapsed-time)! That's a jet's strong point.
See Ya.
Jack
Jack McClure
Mcir...@bigfoot.com wrote:
>
>
> I'll change that Hydro ASAP, promise!
> What is the fastest American Jet boat now?
>
National Jet Boat Assn - Jet class records as shown in the Oct 97 Drag
Boat Review.
Blown Gas Jet - Harold Bruce, "R&D SPECIAL", 142.58mph, 7.46et.
Class rules here are obvious. Harold has had runs of 144-145mph.
Unblown Fuel Jet - Joe Podwoski, "THE GAMBLER", 136.75mph, 7.54et.
Normally aspirated only, up to 650 ci, any fuel (nitro, alcohol, gas,
nitrous).
Joe has been almost 138, but crashed and destroyed the boat in Sept 97.
Pro Gas Jet - Jerry Hicks, "HOT TUB", 128.84mph, 7.69et.
Nornally aspirated, up to 515 ci, gasoline only.
Jerry has runs as high as 132 on gas, and 134+ with nitrous in the next
class up.
Comp Jet - Jim Guthrie, "THINLINE II", 125.13mph, 8.01et.
Nornally aspirated, up to 470 ci, gas only.
Jim bumped this record up in Oct 97 to 128.5mph.
Mod Jet - Larry Edwards - "MAIN EVENT", 125.10mph.
Norm. asp., up to 482 ci, gas only, 750 carbs (2) only.
One time deal! I don't think Larry went this fast again.
Ski Jet - Joe Pisciotta, "ROYAL FLUSH", ???mph, 8.99et.
Norm asp., up to 460 ci, gas only, 750 carbs, no center steering.
Also listed in this issue are records from the Southern Drag Boat Assn.
Pro Gas Jet - Mike Ledford, "DYNAMITE", 125.34mph.
Steve Brule, "HEAD OVER HEELS", 8.37et.
Pro Limited Jet - Gary Ogden, "FULL TIME HOBBY", 113.63mph, 9.12et.
Norm asp., up to 475 ci, gas only, one carb only (this from the
grapevine).
MCir...@bigfoot.com
In article <348668...@pacbell.net>,
jmcc...@nospam.pacbell.net wrote:
> Mike,
Snip
> The Blown Fuel Jet "Going Places" ran 170.58mph in 1993. I've
> (SDBA-Texas area, CSDBA-Missouri area, etc) that have their own records.
> Maybe members of these other groups will post their achievements. Jet
> classes only for me, thanks. :-)
> Last thing Mike - - When thinking jets, think less about speed
> and more
> about quickness, ET (elapsed-time)! That's a jet's strong point.
> See Ya.
> Jack
Jack, Thanks for the enlightenment, I am a fairly new boater, even newer
at Jet Boating, I did not really think about that. When I hear jet boat
(I'm sure like others) I think F16 Jet, speed. That reminded me of a
article I read a while ago, It somewhat said the problem with jet boats
at high speed is water intake. Water is very heavy at higher speeds.
Carl Camper touches on this a bit on his ULTRAC's page. I would hope
soon, that some Jet drive Co. come out with a major break through. Maybe
some sort of impeller that can change shape (spring loaded) at higher
rpm's (sounds good to me!). I would bet one of the PWC (japan) Co's come
up with something first. It seems to me that most of the US Co's are
stuck in some kind of rutt. If I look at some old Magazines, 70's, they
have the same exact jet drives in there? Wow powder coating is new. I
love jets thus far, although I must admit, it is starting to feel like a
Technology Dead END!
What in the Heck do I know anyway.
You seem to be very knowledgeable, what is the latest (dated), public
break through? (diverter, SS impeller, droop snoot???????)
Thanks again