Double Drilling A Bowl

[Jetaholic]

What's the max hp you can run a pump without having to double drill the bowl? And what size are the bowl bolts? 1/2" - 13 or something bigger?

[BrendellaJet]

im running 800 with only the exit side double drilled. No probs.

[cyclone]

i think water pressure and how flat the mating surfaces between the bowl and suction housing and bowl/droop really determine whether or not double drilling is necessary.
you can have 200hp but if the surfaces aren't flat the gaskets aren't going to seal real well.

[Duane HTP]

About the only time you have to double drill is when you are running an old Berkeley. The Dominator, American Turbine, & Aggressor pumps are all designed with a thicker and heavier suction housing and do not need it. We run up to and over 2000 hp on some of them. We do, however, machine the bowl to use an o-ring and eliminate the gasket problems.

[UBFJ #454]

I gotta say that Duane's O-Ringing our bowl really works and makes disassembling and reassembling the pump so much easier. He also O-Ringed our PopOff (which I had my doubts about intially, but, certainly don't now) which makes maintanence of the PopOff a lot easier. At times, our bowl pressures approach 500 psi and no water squeezes out of any of the joints.
Also, neither side of our bowl, a Dominator, is double studded/bolted.

[H20MOFO]

Huh? I have an old berk. What the,are we talkin the split bowl berk???????

[Wizard612]

Back in the 70's comp. Jet double drilled but Ski Jet saw no need... Except for me... Running ski-jet circles I double drilled my nozzel housing which allowed me to accidently mount my nozzel crooked which gave me a bit of down nozzel while still meeting the rules of no adjustible nozzels in class. I have no idea of what preshures are now created at the bowl to nozzel connection but I'm sure that the o-ring solution solves most issues. When you do the math it's amaizing how much force it takes to yank out 6 nozzel bolts at the same time.

[UBFJ #454]

Huh? I have an old berk. What the,are we talkin the split bowl berk???????
Yes, split bowls.

[Wizard612]

OOOps! I re-read the original question and it concerned double drilling the bowl. You mean for the bowl to suction piece? or the bowl to the nozzle? If Bowl to nozzle see post above, if bowl to suction piece I have never heard of anyone blowing a bowl off the suction piece the 3/4" bolts will hold a building off the ground from a crane. and the preshures on that side of the bowl should be extremely lower than on the nozzle side. Seems kind off funny that the original engineers at Berkley sized the bolts the way they did.

[FuelInMyVeins82]

I think alot of people now a days double drill the suction housing and bowl to prevent blowing out gaskets. However if you o-ring it your solving that same problem.

[UBFJ #454]

I'm not so sure it's such a good idea to O-Ring a Berkeley Bowl due to the relative thinness of the walls (and typical core-shift) of Berkeley's Suction Pieces and the thickness of their mounting flange (or lack of, as compared to the Dominator & AMT pieces) ... ???

[Wizard612]

I'm curious are gaskets getting blown in or out on the suction piece side. If blown out it sounds like the pump is being loaded too hard. A shallower or a blocker scoop may be in order. If the gasket is being sucked in you are making some serious HP!!! and the intake is too blocked. The o-ring setup is best if your a racer and constantly tearing the pump down to massage the internals. If your a recreational jet boater you probably have warped surfaces that allow the gasket to fail. some one probably over tourqued the bolts at one time.

[Cs19]

I'm curious are gaskets getting blown in or out on the suction piece side. If blown out it sounds like the pump is being loaded too hard. A shallower or a blocker scoop may be in order. If the gasket is being sucked in you are making some serious HP!!! and the intake is too blocked. The o-ring setup is best if your a racer and constantly tearing the pump down to massage the internals. If your a recreational jet boater you probably have warped surfaces that allow the gasket to fail. some one probably over tourqued the bolts at one time.
Its the bowl gasket that is being discussed, it has nothing to do with how hard your loading the pump, the bowl gasket is up against the bowl pressure (thrust).
Jak, are you still measuring bowl pressure in the droop? 500 psi in the droop is not actual bowl psi.

[Cs19]

What's the max hp you can run a pump without having to double drill the bowl? And what size are the bowl bolts? 1/2" - 13 or something bigger?
Here is my .02
I would double bolt any pump that has 750-800 HP or more, especially the bearing cap if your not running a ratchet.

[Jetaholic]

Here is my .02
I would double bolt any pump that has 750-800 HP or more, especially the bearing cap if your not running a ratchet.
I used to run the Jet-A-Way, but it limited my back seat space so I did away with it. It is a WAY COOL piece to have...does everything it's supposed to do and I highly recommend it to anyone who wants to buy one and is not concerned with limited backseat space. However, why would the bearing cap need to be double drilled over 750 - 800HP?
Also, I'm only running around 500HP estimated...was just wondering if I should double drill the bowl to suction piece and the bowl to droop mounting since I'm gonna be doing a bowl swap here in the next couple months. Figured since I'd have the pump apart anyway might as well.

[Mr. Crusader 83]

My Old Boat Had A Stock 454 With A Cam And Would Blow The Gasket Every Once In Awhile. I Have A 468 With 600hp And It Hasnt Happend Yet. Like Cyclone Said, Its All About The Surfaces.

[Cs19]

why would the bearing cap need to be double drilled over 750 - 800HP?
The bearing cap is taking all the load, its trying to blow the cap off when the pumps working, 4 bolts is fine 8 is better.
Alot of guys run crazy hp and never bother, I like the idea of building the jet-drive bullet proof and not having to worry about anything which allows you to just focus on the setup of the boat.
If you plan on hopping up the motor dbl drill it while its apart, if not dont bother.

[Cs19]

Thanks Jak, so its snoot psi, not bowl psi. Reason I asked is 500 psi of bowl pressure is extreme.

[Clockstart]

Re our nozzle/bowl pressure sensor: We now take the psi measurement in its, the Snoot's mid, side portion.
Note that in a hydralic, or non compressable fluid system such as is the case with water, the pressure at one end of a vessel is the same for all intents and purposes the as in the other end of the vessel. While this is not entirely the case in our case due to the snoot's shape, it's smaller diameter as the water flows to its rear, we feel that it's close enough for our purposes. Additionally, in reality we're not as concerned about the bowl pressure as we are about nozzle pressure as that is what we need to know in order to be able to figure our thrust values ... the number of pounds of thrust we are generating is one of the factors important for me to know for hardware selection purposes.
Now I know we aren't measuring our nozzle psi Knat's On due to the position of our sensor, but, it's very close ... close enough to be a very useful tuning tool. Also by taking the measurement where we do, we get a relatively stable reading ... we get very little instability/high variations (note: We do not have to smooth our data for it to be interpretable in its graphical presentation) due to the motion of the impeller blades sweeping by the sensor and bowl veins that others see when their sensors are placed in close proximity, either immediately fore or aft of the impeller.Daniel Bernoulli (1700-1782) must be rolling over in his grave.
Cs

[Placecraft Dragstar]

The bearing cap is taking all the load, its trying to blow the cap off when the pumps working, 4 bolts is fine 8 is better.
Alot of guys run crazy hp and never bother, I like the idea of building the jet-drive bullet proof and not having to worry about anything which allows you to just focus on the setup of the boat.
If you plan on hopping up the motor dbl drill it while its apart, if not dont bother.
Exactly, when its apart do it right not twice. There are alot of tricks that the old timers can teach you that the new guys are just not as smart.

[Xerophobic]

Im not sure Ive ever seen a whitewater boat with a double drilled bowl but its certainly not common. What we do see more is o rings and the clamps seen at the bottom right of this pic
Cheers
http://www.***boat.com/image_center/data/500/DSCF1907.JPG

[BrendellaJet]

Im not sure Ive ever seen a whitewater boat with a double drilled bowl but its certainly not common. What we do see more is o rings and the clamps seen at the bottom right of this pic
Cheers
http://www.***boat.com/image_center/data/500/DSCF1907.JPG
your clamping around the bowl to keep the gasket in place?

[Xerophobic]

your clamping around the bowl to keep the gasket in place?
While that might work no typically the mating surfaces of the steel nozzles we use arent the best surface to seal, so the clamp is used to help prevent leaks. Most of our aluminum wedges and spacers are machined for O rings, also visable in that picture
Cheers

[cyclone]

XERO...what's the price on those aluminum wedges and what angles have you got them in?
thanks.

[sanger rat]

Whats your price on the blue wear rings?

[Xerophobic]

Haha , guys, guys im in sales and marketing lol You gotta give Bernie a ring in parts
403-347-4565
Cheers