berkley pump problem,need help

[GATORJET]

hello all, i have a problem that i would like to get some help from the members out there that may have been through what is happening to me and might have a fix. i have a new 12jg pump with the pump setback so the cleanout is outside the boat. i have it set up with an aggressor aaa tripple a bronze impeller. the motor is making 775 hp natural and 1125 on nitrous. these are dyno numbers not a guess. the pump is spinning 5500 rpm natural and 6600 rpm on nitrous. my first day out about the forth pass on nitrous the cleanout blew off the pump about 100 feet in the air,it broke both the pivoting bolts off. i'm sure i'm not the only person spinning this much bowl pressure, any advice you guys might have or solutions would be greatly appreciated....thanks for any help you can give

[wsm9808]

I've never had it happen, but the clean out hole is on the suction housing and is not subjet to bowl pressure.
Maybe your shoe/loader is too aggressive and packing more water into your suction housing than the impeller can use and is causing too much pressure to build up in the suction housing as speed increases.

[Cs19]

Ive been though this also.
First off, is this a race boat only where you are always on the bottle or is it a river boat? Also, why are you running a AAA impeller? Im sure you make peak power off the bottle above your 5500.. Tell us about your boat and set up also.
There are two ways I know of to get this handled so it doesnt happen again. One is get a new cover from Roy Miersch, his is a stronger piece and should not break. Other option is get a new berk. cover and machine the top flat and put a 1/4 plate on top of that,I'm yet to see one with the plate break.
WSM is correct, bowl pressure has nothing to do with your problem,inlet pressure is what your dealing with.

[GATORJET]

the boat is an eagle tunnel that is set up to race in a 1000 ft track here in missouri. it makes peak torque at 5300 rpm natural and at 6200 on the bottle. the reason for the aaa is mainly to keep the rpms down at wot and to try and get a decent hole shot without spinning. my thoughts on the cover was to do something like aggressor does with a berk cover but who is roy miersch? i may be interested if he has something better, having this thing blow at wide open throttle was not fun...... thanks for the help

[Mr. Crusader 83]

it sounds to me that you need to run one of these .... its to releave the presure in the pump when you back off the gas or you have to much presure. got this pic from foxwell
http://www2.***boat.com/image_center/data/521/1729100_0474.jpg

[Joey]

hey gatorjet the same thing happend to me in the flat bottom last year in the same place it happend to you. The cure we had but didnt have time to use was a ratchet, but on your boat you would have to move the fire wall :frown: that would run you short on time for sat. and mess up that killer paint job. p.s. show these folks some picks that is somthin to be proud of.

[wsm9808]

A pop off is great for safty for sudden loss of power, but I would not use it as a band aid for your problem. You dont want to have to worry about the pop off going off every time you hit the bottle.
I would suggest you put a pressure gauge on the suction and find out exactly what is going on with your pressures. You will be making blind adjustments without a gauge.
Here is a pic of were the suction pressure gauge is plumbed into the housing on my boat.
http://www2.***boat.com/image_center/data/503/226IMAGE088.JPG

[Cs19]

Ok well i guess you have a handle on the impeller size. :idea:
Roy Miersch is a guy who makes jet parts, hes been around a long time, he also makes the valve shown in that pic above. His cleanout cover is not billet, but its a stout piece (cast).
Get some pics of your boat up, Id like to see it.
Good luck.

[Cs19]

I agree, something might be up with your inlet or set up. Im constantly breaking stuff due to unloading at top speed.
If your racing having inlet pressure is a must have.

[SmokinLowriderSS]

I have to concur with WSM9908, you shouldn't have that much pressure in your suction housing, I don't know what it should be (the experienced hi-tech racers would have tested and mesured thet stuff) but it really sounds to me like way too much shoe digging in and feeding a lot more than your pump can pass. That would also translate into more drag than you want slowing you down.