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wedge on a Tahiti w/ panther jet
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Author:  Cas [ August 4th, 2009, 11:46 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
Unfortunately, when I got out of rebuilding Panthers, I dumped just about all of the stuff so I doubt I have the template I made. As far as a pitch, it's more of a reshaping of the front and back of the impeller blades. If I can get my hands on a Panther impeller, I'm sure I could redraw what I did to the other one. If you can take a life sized pic from the side of one of your impeller blades, I should be able to redraw something close.....we're only talking about a 1/16th inch or so.
As far as the the stator housing goes, I used to fill all the pitting with an epoxy much like the Devcon that Panther sells. I would fill the pitting and then put a layer all around the housing in the area where the end of the impeller blades are. I would then "screw" the impeller into the epoxy, put the pump back together then take the boat to the Napa River. I'd fire the engine off to let the impeller cut it's own clearance. It would make for a very tight pump where that alone would lower the rpms. My 19' Tahiti did 68 at about 4900 rpms, not too much difference than a Berk style pump.
Oh yea, if the epoxy is too thick, sanding will need to be done to make it so the impeller doesn't have a lot to cut through.
Author:  78_Tahiti [ August 5th, 2009, 8:27 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
Cas wrote:
As far as the the stator housing goes, I used to fill all the pitting with an epoxy much like the Devcon that Panther sells. I would fill the pitting and then put a layer all around the housing in the area where the end of the impeller blades are. I would then "screw" the impeller into the epoxy, put the pump back together then take the boat to the Napa River. I'd fire the engine off to let the impeller cut it's own clearance. if the epoxy is too thick, sanding will need to be done to make it so the impeller doesn't have a lot to cut through.


That is exactly How I reshaped the first pump that was in my boat. the guy never lubed the tail (DU Bushing) so in time it had gouged about an 1/8" clearance all the way around the housing. Before I filled it with Devcon F. I was toying with the Idea of making a wear ring of sorts out of something that was not in common use at the time these pumps were designed. I was thinking of either a Teflon or PTFE sleeve to create a snug yet low friction surface for the impeller to seal against. My thoughts were that would help reduce the centrifical effect which causes the pump to leak some of the pressure back towards the intake instead of the direction it should be going.

That I believe is the biggest hurdle in making some kind of major gain in thrust. I now have a bronze sleeved compresser housing. I have about .010" clearance between impeller and housing. I am using a 1/4" wedge in the exit housing right at the end, and only at the top (currently). The reasoning why at the end is this. The water is reaching its max velocity just at the begining of where the exit housing straightens out (about 4" before the end) therefore it should be less likely to cause the flow to be restricted as you have a essentially a constant 4"x4"x4" chunk of water pushing kind of like the difference between swinging a 1 lb hammer and a 4 lb hammer at the same speed. The force it would take to slow the big hammer would have to be much greater. Therefore the little wedge really just adds a little more pressure. Does that make sense?
Author:  78_Tahiti [ August 5th, 2009, 8:41 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
I think a little more experimentation with wedges of different thicknesses, you would find a point where it would start to hinder performance instead of help it. And I'd bet a bucket of TP Seaweed it is totaly dependant upon how much clearance you have between the impeller and the housing. On the the other hand since you cant increase the size of the impeller, Increasing its Bite (like you did for the guy in Fresno) is an area I have been toying with also. :idea: I wonder what can be gained by doing the opposite of choking the tail. Like increasing the impeller pitch and opening up the tail> :?
Author:  Cas [ August 5th, 2009, 9:18 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
There's a company in Reno, can't recall the name right now, that have been putting in a wear ring much like the Ultimate wear ring for the mixed flow pumps for a few years now. For description purposes, it's looks and feels like a nylon composite. From what I was told by a couple of people that had it installed, it worked pretty well.
And yes, what you posted made sense.

BTW, I believe a person can still buy the plans for Panther's adjustable intake directly from them. From what Steve told me, they quit offering them up for sale due to liability issues.
Author:  Cas [ August 5th, 2009, 9:50 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
78_Tahiti wrote:
I think a little more experimentation with wedges of different thicknesses, you would find a point where it would start to hinder performance instead of help it. And I'd bet a bucket of TP Seaweed it is totaly dependant upon how much clearance you have between the impeller and the housing. On the the other hand since you cant increase the size of the impeller, Increasing its Bite (like you did for the guy in Fresno) is an area I have been toying with also. :idea: I wonder what can be gained by doing the opposite of choking the tail. Like increasing the impeller pitch and opening up the tail> :?


I don't know that it would do much for top end but it would allow more volume to flow through it. The limiting factor is still the intake and intake housing as there isn't much that can be done such as loaders, blockers and shoes.
Author:  78_Tahiti [ August 5th, 2009, 5:05 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
I take it your refering to Steve @ pantherjet. I too have had a few conversations with him. Besides just to order parts. I haven't heard of an adjustable intake. Is it some sort of scoop for the pump intake?

Cas wrote:
There's a company in Reno, can't recall the name right now, that have been putting in a wear ring much like the Ultimate wear ring for the mixed flow pumps for a few years now. For description purposes, it's looks and feels like a nylon composite. From what I was told by a couple of people that had it installed, it worked pretty well.


I figured someone could. It seems to me sealing the outside of the impeller would offer a great hole shot. I realize I dont have a 550lb. light layup hull, But Im always looking to improve things a little and experiment a little. I tried the panther jetovator. What a P.O.S. that is. I posted 2 short vids of it last year. They can be found here.
http://www.youtube.com/watch?v=09NxDK56LAE

The Jetovater in action
http://www.youtube.com/watch?v=ufOL5-j8VWI

What amazed me was how crude it was. Why couldn't one just lop off, say the last 3" or so of the exit housing, weld a flange on it and bolt up a mini droop with a place diverter and berkley style steering. Its so much better in design and operation. I have heard of an energizer kit for the panther. But that kind of seems like adding half of a better pump, with all the original problems. Intake area very hard to modify, limited to almost as cast size for the intake volume. Let me know if you remember the name of those cats in Reno. I would be interested in what they have learnt about Panthers. Steve mac
Author:  Cas [ August 6th, 2009, 11:18 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
ADM Boat Works in Southern Cal has been doing exactly what you said, cutting the Stator and fitting a Place Diverter to it for a few years now. Through the years, I've heard both good and not so good on the results of the change so I guess it's kind of a crap shoot. What I don't know is what kind of performance the people were looking for that complained about it?
I don't know the cost for them to do the retrofit though. Besides that, I'm not sure they are still in business as I've noticed them selling off quite a bit of stuff on ebay.
The results you got with the Panther Diverter is interesting as I experienced quite the opposite. It didn't give a big ole rooster tail but it surely changed the attitude of the boat and even gained some speed when it was about 3/4 of the way up. Oh yea, that was also on my 19'er and not the 21'. You're spot on about the crudeness of it although after adapting an electric window motor and a switch to it, it wasn't too bad.
Back when I was rebuilding the Panther pumps, I was contacted Steve asking me to be a dealer and an authorized Panther shop, he let me in on a couple of other items that Panther had/has for add-ons. The adjustable intake was one of them but as mentioned, there was a liability issue due to someone closing it off to fast which made the but flip.
Here's a couple of the other items-
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Author:  78_Tahiti [ August 6th, 2009, 5:01 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
With the Panther Jetovator the only slight gain I felt in my boat was when it was angled about 2/3 up It seemed to free up the hull a little at WOT. at speed when in full up position felt no different then 2/3rds, however the tail was noticebly higher. Perhaps playing with the stock ride plate may have changed how the jetovator acted. I only had the exit housing with the jetovator available for a day. Unless I wanted to buy it. :oops: I opted not to. With the jetovator in strait or any down position the boat was 10 percent slower. If I nailed it whith it in any down attitude at all even from a dead stop I had spray shooting out of the steering nozzle towards the transom on both sides, as if the bucket was half closed.

However, you have inspired an idea! Im thinking about using an I/O trim Motor and a couple rams to make my ride plate adjustable on the fly. That to me stands out as a great possibilty to make some interesting gains. what you think?
Author:  Cas [ August 6th, 2009, 5:10 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
I think that's a good idea! With it being adjustable from the driver's seat, I'd also use a longer ride plate and just put it in the up position when you need to go in reverse.
I played around a bit with different ride plate lengths but the thrust would hit it when reversed. I even tried a longer one with a big relief cut out so the water could flow through it when reversing but it didn't make any difference....actually didn't work all that well in reverse either :oops:
Author:  78_Tahiti [ August 8th, 2009, 1:40 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
OK, I have the word out. lets see if I can scare up an I/O trim pump and a couple rams cheap. Maybe I should go out to my collection shed in back yard. Sure seems like I had a pump or 2. Hmmm.
Author:  Big Nasty [ August 8th, 2009, 10:52 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
i added plates on mine you can see them just above the trailer roller and electric trim tabs wouldn't this be the same??
Image
Author:  78_Tahiti [ August 8th, 2009, 6:28 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
Similar idea chris, except you have a ride plate (on pump) and trim tabs. That are essentially making your boat longer. Because even though they are adjustable (the tabs) you are increasing the wetted area of your boat, which causes friction, which reduces speed and uses up horsepower. if you have ever tried your boat without tabs, just using the ride plate. It acts different. Each position on the ride plate makes the boat do different things. trimmed up up it makes the boat looser (bow up) and increases speed. trim down, makes the boat wetter, feels more stable, reduces speed, but planes a little faster. So my thought is that putting hydrolics on my stock ride plate instead of the fixed struts I could control the trim without adding the extra drag of trim tabs. At least that is my understanding of how it works. Now JEThrow tried that panther droop on his 19 and said it made it feel way 2 loose, however on a 21' like we have it may just help it unwett a little. How does your boat turn at speed. say about half throttle and you cut the wheel do you have to hit it hard to maintain a decent turn (bow heavy) or does it feel like the nose just comes around (bow light). Its the nature of the semi v bottom a little to bite when ya turn it butt i think with an adjustable ride plate ya could bow up when just sarting the turn and spin a little more from the tail intead of up front. SMac
Author:  Big Nasty [ August 8th, 2009, 8:05 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
I get what you are saying and it makes since.
I put the trim tabs on mine only for one reason and that was for rough water and to cut through wakes.
I found no differance in speed from before ( not having tabs) to after ( having tabs in the up position)
I also found little differance in turning as long as it a wide enough turn.
it has allways layed down bow first if the turn was too tight and before I added the 4" Trim Plate it used to skip on the turns now it's way more stable in the turns without any lose of speed do far.
I got that droop from Cas and I have an extra stator housing I was going to do the reduce modifacation on the exit and then hit Berryessa for a weekend and do some testing with the different parts
Author:  78_Tahiti [ August 9th, 2009, 5:35 am ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
Kool, be sure and post back about how it does, Hell who knows. We do enough experimenting, we are bound to hit on something that you can feel in the seat of your pants. I run a small wedge in my exit housing now. Wow I dont have a picture. How Unusual. LOL! I'll take one later and post it. its only on the top of the exit (1/4" alum plate, tapers down to exit housing size towards the impeller. Its only about 1" deep.) what kind of speed @ what rpm are you getting now.
Author:  Big Nasty [ August 9th, 2009, 12:20 pm ]
Post subject:  Re: wedge on a Tahiti w/ panther jet
At Lake Hogoan WOT I hit 56 MPH @ 5400 RPMS Thats were I had my rev limiter set because of the new motor
By the numbers I am hitting around 557 hp @ 5500 rpms and 581 tq @ 5000 rpms.
So I'm right there in the correct range i just need better / efficient / thrust out of the pump
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