Ok... HERE'S the real reason...

[H8Monday]

...that I'm trying to understand the ratio of pump RPM/suction/nozzle whatever to speed..
My friend and I have the same boat. 20.5 Elim sport cruiser. Mine is factory orig (WITH water in the @#% damned oil...) His on the other hand:
Bare hull, no interior whatsoever, no carpet, no side panels, nothing. No deck hardware. Two bucket seats only. We checked the bottom with a 4 foot straight edge. the bottom is still straight. (It had been straightened when it was painted 3 years ago)
The engine: 488 inch Ford, Major head work, Steel rods, big ass roller cam (sorry, don't know the specs) MSD ign, 10-71 Mooneyham, 2 Barry Grant 850's, Rewarder headers. SUPPOSED to be about 850 hp. It makes 12 lbs of boost. Cost $25,000
The Pump: Berk JC with a loader and Place Div. the impeller is a Berk SS AA. The pump is unmodified.
We live at 4500 feet elev.
My boat, 4600 RPM, 55mph.
His boat, 6500 RPM, 74mph.
He thought that with that much engine he could hit 90. He is soo disappointed in the boats performance that after 4 outings this year, he has parked it. I know that you guys are going to jump up and down and say, "The Pump... MPD the pump"...but do you really think there is that much performance to be gained there?
He spent a shit load of money on the motor, and he is really unhappy with the results, so he is very reluctant to spend another 3 grand on the pump.
The way he feels right now.....
"Eliminator for sale...big ass motor... kinda slow...$15,000.00"
I've been trying to convince him to spend a little more on it and keep it. Help.

[BLOWNDRAGBOAT]

HEY DUDE!!!!! I LEFT YA A MESAAGE on your last post...Now that you gave up some particulars I can help ya...I see several problems already. You want me to tell ya here or over the phone?

[H8Monday]

Your spelling is pretty good...lets have it here, so that everyone can learn from my buddy's choice of mods.

[rivercrazy]

If its an unmodified berk, there is major mph to be gained by spending the $$$. Most stock boats pickup 3-6 mph bluebrinting a older berk.

[squirt]

the pump*********the pump*********the pump
don't know the hull but if your spinning 6500 rmp and going 74mph that thing is either made out of cement or the pump needs to be worked. LV has charts for rpm, mph, and some hulls so if you ask he might give you an idea of mph for hp and hull design.

[Blown509Liberator]

Yes I agree... the pump the pump
I have a 509 850hp Spinning a MPD race prepped SS A impeller 6000 rpms and i an running 94 mph. I have dialed out most of my hop and now playing with shoe deapth so add more speed. I should be in to 100's by next summer but up here in Chicago it is no been in the 50's it gets really cold at 90mph at that temp. it's always nice to have the tears freaze to your face as you make a wot pass in the cold weather.
MikeW

[BLOWNDRAGBOAT]

Ok..first off.My names Rob. I build racing engines for a living. Some of my customers are past and current Promod racers in NHRA/IHRA as well as alot of offshore racing teams.
Just by looking at your latest post and not seeing these things first hand, heres where I think your problems are.
The eliminator hull your using is more of a daycruiser than a raceboat. IT'S HEAVY. I personnaly wouldn't waste my time or money trying to get that boat to anything more than about mid to high 70's or so. Forget seeing 80's let alone 90's with that boat.
As far as the engine is concerned, I build more GM based (merlin, rodeck, kieth black) type engines but fords are great torquey engines. The one thing that pops out at me is that your running A 10:71 MOONEYHAM BLOWER @ 12 POUNDS OF BOOST MAKING APPROX. 850HP. If it really is a 10:71 running 12 pounds than it should be making alot more horsepower than that. Thats a lot of boost with a big blower. Those are typically numbers you would see using an 8:71. A 10:71 @ 12 pounds of TRUE boost will make ALOT more than 850 hp. Are you running a superchiller with this? Especially in that thin air. Thats a big blower NOT to be. Were are you measuring the boost from? Sometimes on smaller motors with larger blower such as yours, boost can backup into the intake manifold and when that happens it shows up on the boost gauge as boost. However, its not a TRUE boost. Anyway, the motor sounds pretty stout but double check that blower size.
Another thing I see is that your using a JC pump. Berkley made this pump as a cheap (INEXPENSIVE) pump for mass produced HEAVY boats. It is designed to move alot of water at a very low rpm. It becomes its worst enemy at anything more than about 4000 rpm. It simply can't move the volume of water. I would like to see ya run a blue printed JG pump with an A impeller and a stuffer since heavy boats tend to cavitate without it. Are you running a shoe and plate? If not you need one. Since that thing is such a heavy boat, I would imagine that your still running ALOT of wetted surface as well. I would be able to tell if you had a picture of it on plane. I wanna see how much boat is in the water. Those ar just a few things that pop out at me. Hope it helps. I will be glad to give you my shop number if you wanted to discuss it furthur.

[fryzll]

That hull sounds alot like the one my bro had. His was a 82 Eliminator closed bow V hull inclosed motor w/ the jump seats on both sides of the motor cover. It had a Hardin Marine BBC (330 h/p I think) w/ a Berkley. If it is the same thing I personally dont think there is alot you can do with it. That thing was a PIG. Dont get me wrong, it was one of the nicest riding small boats I have been in but it was soooo heavy. I was told his was a 20.5 Sport Cruiser but it didnt say Sport Cruiser anywhere on it. His was White w/ browns and tans and had wood grain looking stuff on the bow in front of the windshield. Yours might not be the same type of hull so dont hold this against me http://free.***boat.net/ubb/biggrin.gif .
Chris
[This message has been edited by fryzll (edited September 27, 2001).]

[BLOWNDRAGBOAT]

Oh ya....One more thing..condesation is pretty common in jetboats. A few reasons why are 1) Your oil isn't getting a chance to get to it's PROPER operating temp. and that helps create codensation buildup and THAT inturn creates a tiny bit of contamination in the oil. Another reason why jets are so hard on unproperly built motors is that tend to blow headgaskets. Water shows up in a cylinder or on a plug check and most people feel like the motor is going bad. Whats most likely happening is this. Jetpumps feed a tremendous amount of water preasure and that water preasure sometimes can blow past head gaskets and into cylinders. If it does it enough than you hydraulic a piston and the party is over. Your engine,as are most head gaskets, designed to withstand certain water preasures. Something along the lines of 12-15 psi. A jet pump can feed it well over 300psi. I have cured this problem 2 ways with my engines. 1)I O-ring my engines and I install a water preasure valve on the intake side of the pump. I set it @ 15 psi and leave it alone. Haven't blown a head gasket due to this problem in 3 years.
Your condensation can be cured by simply letting the motor build some heat.

[Blown509Liberator]

BLOWNDRAGBOAT
What Water regulator do you use? Do you sell them?
MikeW

[Jetmugg]

The pump, the pump, the pump, and then the hull. I just sold my Gullwing which ran a best of 82.6 mph at 5200 rpm, with an MPD-prepped A/B impeller. A 25K engine with a stock pump is like a pro-stock dragster running on dry rotted Sears radials. Tell your buddy to put some work into that JC, and possibly upgrade to a split bowl pump. Make sure it's got a ride plate, shoe, and loader, or just go out and buy a high-perf hull to put his drivetrain in. If you want to go fast, you've got to have a fast hull. Something air-trapping works well.
SteveM.

[Jetmugg]

Oh yeah, I didn't even have 500HP to play with.
Steve.

[flat broke]

Those that have been pointing you in the direction of the hull are correct. I have a Dana that is a splash of the Eliminator. It is a heavy boat, and if your friend wants to run fast, I would pick a different hull.
All that asside, I'm a little shocked at the HP to mph factor. Turning an AA at 6500, I would think he could do a bit better than 74. Especially considering that my goal is 70 on a shade over 500hp at 5200 rpm. I have had fuel system problems so I can't compare, but I would agree that the pump might want to be looked at. Someone also mentioned your wetted surface as a point of degraded performance. With that hull there is a lot of drag, and any mods that would create lift would get your friend in the right direction. The line about the JC being a cheapo version of the JG... I take exception to it. For the most part the bowls are the same on the inside and in fact, the vanes are longer on the C which should straighten your thrust more before it hits the nozzle. I would say however that a split bowl would probably be in order for attaching a droop (I've had mixed input as to whether or not one would help on my hull) in order to help unwet more of the boat. Regardless of how many more HP he might have over 850, I really hope there is something wrong in his pump or setup, cause if not I'm not going to meet my goal with the HP I'm currently running. Then again, I also have some MPD magic on my side and kept the compression at 9.1 so I could add the blower if need be. ;-)
Good luck to you and your friend,
Chris
[This message has been edited by flat broke (edited September 27, 2001).]

[hottrodder]

H8Mondy: I'm kinda in the same spot as your buddy. A buddy and I spent two years building an '88 Hallett Vector from bare hull. Pump was demanded due to where we do most of our boating on the sandbar infested waters of Blythe. I'm running a 454 intercooled Gentry twin turbo. 625 HP @ 8 lbs. The pump is a stock Dominator 12S w/ A-AA impeller, Place diverter, ride plate, 5/8" shoe, and open center ramp loader. First time out it ran 75 @ 6000 with an A and almost no boost. It porpoised BAD! and was generally ill-handling. No boost and big RPM lead us to belive that we weren't loading the pump. So we radiused the keel 2' in front of the intake and changed the impeller to an AA that we have since trimed to between an AA and A. We added trim tabs and installed a turning fin. The tabs now eliminate porposing when I bury the nose and the turning fin has helped it to go right, not just left. Today the boat runs 71 @ 5500 w/ a full 8 lbs of boost. The Vector hull is a little over 21' and 8' wide. I don't know how much it weighs but a few have told me they're heavy. The boat was built for family (2 1/2 yr. son and 3 mo. daughter) so I'm happy. But it seems all the adolesents with their 18'ers run 70ish in Blythe. I can stay with them but I sure wouldn't mind another 3-4 MPH so I can just ever so slowly walk away from them http://free.***boat.net/ubb/smile.gif.
BDB: I got away from the water pressure issue by running two bottom pick-ups. One to a raw water pump that feeds the oil cooler, into the motor and out the double wall stainless pipes. The other feeds the inter cooler and dumps out the side.
B509L: I'm not familiar with Liberator hull. Is it air entrapment? What have you done to the pump and who did the setup?
Thx, HRr

[H8Monday]

Well BDB...good eye, I called Rick, (the boat owner) and he told me that the blower was indeed an 8-71. (the 10-71 is on our OTHER buddy's 572) I don't have any great picts of the boat, but here are a few to give you an idea of what we are working with.
first, the hull (mine)
http://www.pirate4x4.com/ubb/uploads/Mine.jpg
Whoops!! Too much 'wetted area' for sure. http://free.***boat.net/ubb/wink.gif
http://www.pirate4x4.com/ubb/uploads/Myboat.jpg
Rick's
http://www.pirate4x4.com/ubb/uploads/Rick1.jpg
and here are a couple that show wetted area, however, the place diverter was in the 'show' position, rather than the 'go' position.
http://www.pirate4x4.com/ubb/uploads/Rick2.jpg
http://www.pirate4x4.com/ubb/uploads/Rick3.jpg
But I mean, really... its spinning a AA at 6500 rpm! its NOT the Queen Mary, it should run faster than 74. Its not THAT heavy... it doesn't even have carpet! Again, mine goes 55 on 320 hp.
[This message has been edited by H8Monday (edited September 27, 2001).]
[This message has been edited by H8Monday (edited September 27, 2001).]
[This message has been edited by H8Monday (edited September 27, 2001).]

[BLOWNDRAGBOAT]

Hey there FLATBROKE I see now how shit gets started.....I NEVER said the JC was a "cheapo" replacement to the JG. Its a FACT that the JC pump is a low performance pump...PERIOD. It was designed to be installed in heavy boats that needed alot of thrust at a very low rpm to get it moving. Heavy daycruiser style boats were never intended to be fast or even quick..Maybe the word dayCRUISER should be a clue. What I also said was that a JC pump in stock form becomes NON efficient above 4000 rpm. It CAN'T handle the water volume that a JG pump can. You also stated that you don't really see a difference in the bowls except for the fact that a JG is a split bowl. I hate to argue and thats not my intention however, there IS difference between a JC and a JG. Without getting into technical stuff, the JG can handle much more volume at a much higher flow rate than a JC. I not telling you anything that Greg Shoemaker @ gsmarine won't back me up on or anyone else that makes a living doing this. Just wanted to clear that up. PEACE.

[H8Monday]

I"ve driven the boat several times. The boat NEVER porpoises, and would never be what I call 'ill handling.
With the place diverter up with about a 4ft high 'tail', the water breaks just in front of the motor. With it in the full down position, the water will break in front of the driver.
The pump does not have any shoe or rideplate. The only type of loading the pump gets is from a loader grate.
You guys think that pump mods could get this boat to see high 80's?

[BLOWNDRAGBOAT]

H8...IF I HAD THE CHOICE WITH YOURLAST POST I WOULD GIVE A SHIT HOW FAST MY BOAT WENT....IN FACT IF THAT ASS WAS AT MY HOUSE THAN I WOULD HAVE TIME TO SCREW WITH BOATS!!!!!!!!!!!AS THE GREAT RICK FLAIR WOULD SAY>>>>>WWWWWWWWWHHHHHHHHHOOOOOOOOOOOOWWWWWWWWWWWW WWWWWWWWWWWW!!!!!!!!
Anyway, thats a nice looking boat. i know in most terms you don't think that your boat is very heavy but wieght is CRITICAL in jetboats. I see boats all day long that are light as hell and haul serious ass(NOT LIKE HER ASS THOUGH) and as soon as you put someone riding shotgun, the boat drops 3-5 mph on the top end. Thats why real fast jetboats are light and small. Anyway, your boat MIGHT see 78 if the pump,shoe and plate are setup right. Just the facts...Just think of it like this...As your boat was meant to put a bunch people and coolers on board and go out and play all day in different types of water without to many hassles. Thats what the boat was built for....My boat only has room for me and a passanger and a SMALL cooler. My boat can go the same places as your BUT it will beat the crap out even Stone cold himself if he was riding in it. If it were me and I owned your boat, I would put the interior back init make it nice and comfortable, load that SWEET ass in it and go find me a nice quiet liitle cove. GET MY DRIFT? I bet the other guys would agree. Go out and get a tunnel if you wanna have a nastyass jetboat. If you can't find one, I have a few here at my shop I could make ya a deal on. PEACE BRUDDAH!!!!!!!!

[fat rat]

Hey H8Monday, I think BDB is right.....you can't have the best of both worlds, call Eliminator or someone really knowledgable of your hull and find out what your max hull speed is and what kind of HP it takes to attain it........you'll probally find out your in the ball park. The money you are gonna spend to hit high 80's would be better spent on a different hull.....pull your motor and drop a stock unit in its place and sell it to someone to use as a day cruzer...what it was meant for and see what BDB has for sale. You'll be money and MPH ahead.

[Blown509Liberator]

HotRodder
Liberator hulls...well just go look at a Daytona add 8" more to the transom and you'll have it.
http://nothinbutjets.homestead.com/files/10005.jpg
Here is more pic if you want to see http://nothinbutjets.homestead.com/Liberatorpic.html
[This message has been edited by Blown509Liberator (edited September 28, 2001).]

[Cas42]

how'd you get a picture of my wife?

[DOHARA]

MAN THATS A NICE POOP SHOOT :P

[jet496]

To Jetmugg or anyone else: I would have asked this question earlier, but everytime I got to that first picture my brain went blank (I must have a neurological disorder or something)...Anyway, I have a 21 foot Ultra Stealth. There's definetly some hook in the bottom. Ultra told me that from the beginning, knowing they were in the process of re-tooling the new hull bottoms to be Ultra-straight (John West gave me the choice to wait...of course I couldn't wait). I'm fine with it. 60 mph with my wife & kids is perfect (WHAT?).
QUESTION: I have a 496HO with an "A" impeller. Turns 5000-5200 rpm (5200 out of the hole then levels to 5000) @ 60 mph (barely). Knowing the HP I have, how do you think I can get more speed (of course I don't want it, 'cause I'm satisfied where I'm at...yea, right).
Different impeller? I just changed the "AA" to an "A". Originally had a "B" but was hitting the rev-limiter. They've since eliminated the rev-limiter.
Talk to me!
[This message has been edited by jet496 (edited September 28, 2001).]

[Jetmugg]

The best advice I have for making a jet boat run up to it's full potential is to call Jack at MPD. He can unleash all of the potential in the pump. Then all you have to do is make as much horsepower as it takes to go as fast as you want.
Steve.

[HammerDown]

As for that photo, Damm...now thats a nice turd cutter!!!

[LVjetboy]

Hammer, I'm thinking...can I have those after she's done with them?? Nice spank-bank material :) But then I'm slightly twisted...certainly not a good role model for those with developing values.
Hmmmmm...maybe time to start a new thread here. See above?
jer

[H8Monday]

Well...Its official.
Eliminator for sale....big ass motor...kinda slow.
email me for more particulars.

[Kwicherbichen]

BDB, sounds as if you really know your sh!t about jetboats....Damn brutha, if you ever wanna loose one of your hot BBC's let me know. Maybe we can put one in my tub gratis the same way Barney got his new motor. I'll even be your official OP6CIII Taxi so you can show it off. Just a thought.
Brian

[flat broke]

BDB,
Not trying to start shit, but I do have a question. You stated something to the effect that the C was designed to move a lot of water for big boats at lower RPM(I'm not quoting directly so don't jump me on it). Makes sense as I have seen lots of Day cruisers that were outfitted with Cs. But later you said that the G moved more volume and that was the reason it was superior for high speed aps. My understanding is that mixed bowl pumps use pressure to attain speed not volume. An increase in volume would indicate a decrease in pressure with all other dynamics being equal. So how then is the G better? Basically what are the internal structural differences that make the G better? Again, I'm not trying to stir up shit. If you have some info, I'd love to see it as thats how we all learn. But if its just word a word of mouth issue without description as to why, I'll stick with my own observations of both bowls. Either way, thanks for the input.
Chris

[BLOWNDRAGBOAT]

No offense taken Flatbroke.....Its sometimes hard to get your point across in these threads. To make a very long story short on the differances between the 2. A g pump is a higher performance pump PERIOD. I am now selling aggressor pumps and parts but in anycase, the G moves more water at a higher discharge rate than a C because in has the ability to flow more water at a much higher rate and velocity. I can get more technical in the differances if you would like to call me shop. I would be more than glad to explain the differances IN DETAIL. Its much easier than doing it here since so much gets lost in the translation. I have all my data right here in front of me so I am waitin for your call. As you can guess, I don't like to give out my number in an open forum but if you email me at BLOWNDRAGBOAT@YAHOO.COM I will give ya the number..PEACE

[ChetCapoli]

Hey BDB,
what do you think of the aggressor bowl as compared to the berkeley if you dont mind me asking?
thanks in advance
chet

[fryzll]

Hey H8, why doesnt he just yank the motor, stick a stocker 460 in it and sell the boat that way? Then go find a nice tunell hull less motor, flop the blower motor into it and PRESTO, he now has a triple digit hot rod. I would think you could find a nice 19 ft Daytona , Southwind or Placecraft tunell for around $5000.00 less motor. Thats what I would do but hey, I hardly listen to myself anyway http://free.***boat.net/ubb/biggrin.gif Oh well, just a thought.
Chris

[H8Monday]

Originally posted by fryzll:
Hey H8, why doesnt he just yank the motor, stick a stocker 460 in it and sell the boat that way?
He has talked about it. He thinks he wants a GN boat. We go to the circle races every year at Burley Idaho, and the GN class is fun. 21 footers with v-drives and big ass motors doing triple digits. He thinks he needs a Raysoncraft. I told him that a good 'ole Schiada v-drive would treat him right also.