SoCal Jet Boats

Tech Talk => Jet Pumps => Topic started by: ralph on August 10, 2012, 08:36:30 AM

Title: How hard should it be to turn my pump by hand?
Post by: ralph on August 10, 2012, 08:36:30 AM
I'm new to jet boats. I've got a Mariah jet boat with a dyno confirmed 640 hp at 5500 rpm. The jet is a Panther with an American Turbine energizer kit, by Jet Boat Performance I believe. I can't get more than 5300 rpm out of it. The jet's probably four years old, and the previous owner said he had trouble with, and replaced at least one bearing. Should I be able to turn the pump easily by hand? (cuz I can't.)
Ralph
Title: How hard should it be to turn my pump by hand?
Post by: 74hondo on August 10, 2012, 09:06:43 AM
Both of mine turn by hand when they are disconnected from the motor. Easily. But I have never tried it on a brand new pump so I don't know if that's how it is on a "perfect" pump. I would still figure being able to turn it though.
Title: Re: How hard should it be to turn my pump by hand?
Post by: ka0tyk on August 10, 2012, 09:08:17 AM
i can turn my panther pump by hand...  i dont have the hp you do, just a run of the mill 454, nor the energizer kit but i get 5200'ish out of mine. 
Title: Re: How hard should it be to turn my pump by hand?
Post by: 1972Challenger on August 10, 2012, 10:51:33 AM
i have a jacuzzi wj and it turns easy by hand when the motor is disconnected
Title: Re: How hard should it be to turn my pump by hand?
Post by: ralph on August 10, 2012, 12:36:55 PM
I still can't see a tight pump eating 100 hp (Charts say 5300 rpm =530 hp). Nothing's changed since the dyno, so something seems wrong. I'm trying to figure out where to start looking. Getting more hull out of the water will improve my mph, but rpm stays the same, right?
Title: Re: How hard should it be to turn my pump by hand?
Post by: Marcsrollin on August 11, 2012, 09:03:21 AM
Are you sure your reading the dyno sheet correctly? You might be looking at corrected HP. Post your dyno sheet up.
Title: Re: How hard should it be to turn my pump by hand?
Post by: pw_Tony on August 11, 2012, 09:32:59 AM
Even with an Energizer kit you're going to turn more RPM than a Berk if you have any horsepower. It shouldn't take that much power to turn to that RPM, the chart doesn't quite work for your case... or at least from the other energizer kits I've seen/ played with. A few things can make the pump hard to turn, a new rope seal, debri in the wear ring/impeller, a tight new greased bearing etc. But if you can turn it over with some channel locks and it's rough, instead of smooth, then something's wrong.
Title: Re: How hard should it be to turn my pump by hand?
Post by: ralph on August 12, 2012, 12:35:47 PM
Marcsrollin, I've got to scan that dyno sheet. But it's not corrected far, we're at 700ft altitude and mid 70 temps. PW_Tony, my 3 point mount is a bitch to line up, and the motors got to move forward to disconnect the pump, so that's not happening till fall. Thankfully, it's a blower motor, Chevy 468 with 6-71, so more power's just a pulley switch away. It's 10% underdriven right now, only 3lbs boost at WFO. At 10% overdriven, 8lbs boost I'm at 703 hp at 5500rpm's, so that'll help. According to the damn chart again, over 5000 rpm it takes 100 hp for every 300rpm gained. Maybe I should just stop reading the charts! ;D
Title: Re: How hard should it be to turn my pump by hand?
Post by: ralph on August 14, 2012, 10:18:41 AM
[attachimg=1][attachimg=2]
Lets see if this works.
Ralph
Title: Re: How hard should it be to turn my pump by hand?
Post by: ralph on August 14, 2012, 10:22:24 AM
OK, it worked, but they're HUGE! We stopped at 5500 even though hp was still climbing. Probably should have gone to 6000 just because, but I didn't.
Title: Re: How hard should it be to turn my pump by hand?
Post by: ralph on October 09, 2013, 10:58:11 AM
Well, I finally stripped the pump down. Hard to turn and rough feeling. Once the pressure's off it the bearing feels smooth, but I'll replace that and the seals since I'm there. Found pieces of one seal inside. It's an A impeller which should only take 537 hp to turn 5300rpm, which is where I max out. What should the wear ring look like? Smooth?  Mine's got some grooves to it.
Ralph
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