SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: WhyNot76 on March 12, 2015, 07:53:20 PM
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So I'm thinkin about cleaning up the edges on the grate and cleaning off whatever the hell the red wax crap is... Is it worth it to knife edge the grate and maybe clean up the bubble shape in the intake area?? And just to be clear, I'm just havin some cold bud lights and layin under this thing "thinkin"... Ha
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I would remove at least every other bar on that rock grate if you can't lose it altogether. All those bars close up a lot of cross-sectional area that could be loading the impeller harder.
If you really want to knife-edge it, put an elongated elliptical radius on the leading edge and knife-edge the trailing edge.
I seriously doubt that you would see any gain from all the work put into knife-edging.
Is there anything you can do to blend the transition from the hull into the pump (without grinding the fiberglass too thin)?
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I could remove the grate but would like some sorta protection, I was thinking about every other bar(removing them), and then just kinda sharpening the edges up a bit on what's left
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The damn things aren't very rounded at all, I have a clue about how water flows so just "thinkin"...🍻
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I would remove at least every other bar on that rock grate if you can't lose it altogether. All those bars close up a lot of cross-sectional area that could be loading the impeller harder.
If you really want to knife-edge it, put an elongated elliptical radius on the leading edge and knife-edge the trailing edge.
I seriously doubt that you would see any gain from all the work put into knife-edging.
Is there anything you can do to blend the transition from the hull into the pump (without grinding the fiberglass too thin)?
it's awfully flat inside as far as the "dome" underneath
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If u want performance out of a panther u need to upgrade to the American turbine energizer kit. I have one on my 78 Tahiti and it ran 75+ with a zz4
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Yeah Panther is kind of a pain. Hard to reach they are still in Oregon I think lol small shaft no performance parts.
Had 1 on a Tahiti. My buddy bought the boat the entire pump got redone blueprinted and the rear of the boat got beefed up where it bolts on the transom then re-glassed can go to 450 hp I think max and too much will make it cavitate n run itself outta steam.
All that and end the end wasnt too far off from the energizer conversion. Thats alot of coin though. You could buy another boat for damn near conversion price (one with a berk)
Having said that what I liked about the Panther was excellent low speed manoverability and I could step on the ride plate n hop in my boat.
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I think i have a panther rock grate in the garage you can have to experiment with . Im in Riverside
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I experimented... Went from this
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To this lol, shaped it up a bit and ditched the two outer bars for now.
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And honestly I don't think a 3,000 dollar energizer is worth it. The boat runs 72 wide open with just me in it, if anything I would pick up another with the berk and swap it but for now I'm pretty content.👍🍻
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And honestly I don't think a 3,000 dollar energizer is worth it. The boat runs 72 wide open with just me in it, if anything I would pick up another with the berk and swap it but for now I'm pretty content.👍🍻
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. I would have to agree with you that boat runs great with the Panther pump and surprise most people. If you had a berk in it the only thing that would be better is the diverter. I'm not sure where in the horsepower realm that pump start to fail. But it is a bad ass boat enjoy. I will give you a ride in the winger this summer.
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. I would have to agree with you that boat runs great with the Panther pump and surprise most people. If you had a berk in it the only thing that would be better is the diverter. I'm not sure where in the horsepower realm that pump start to fail. But it is a bad ass boat enjoy. I will give you a ride in the winger this summer.
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oh I'll definitely take you up on that one lol👍👍 I gotta get over there by the shop one of these days and introduce myself.
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oh I'll definitely take you up on that one lol👍👍 I gotta get over there by the shop one of these days and introduce myself.
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. Yeah that would be cool let me know when. I will
Make sure to be there
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So the little messing around with the intake area and the rock grate really did make a noticeable improvement, the boat seems to pull a lot harder and I noticed a lil more on top end. Makes me wanna play with it some more but for now it's great👍👍👍
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Yeah no trim control sucks the Panther had a long low rooster. Sucked to be towed behind it for watersports.
If you have a Panther dont look at the others guys main shaft (on his Berk) its huge
Like my Grandmother always said "Thins in but fat's where its at"
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Man honestly I don't have any shaft envy LOL, my boat actually does great with the Panther, the fact that it gets out of the hole a lot quicker and gained some performance after playin around with it has me stoked lol
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I think you need to remake the panther commercial. Let's custom build a diverter for it. That boat would surprise most of the guys.
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I think you need to remake the panther commercial. Let's custom build a diverter for it. That boat would surprise most of the guys.
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I'm all in.. Lol
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Theres a guy with a white and yellow with wood grain Tahiti mini day in Sac area that has a diverter on his panther. nice guy I dont remember his name but yeah its possible.
Stock or low hp Panther is fine
I don't think You can remake that ole Panther video. How can you do that classic justice.
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So the little messing around with the intake area and the rock grate really did make a noticeable improvement, the boat seems to pull a lot harder and I noticed a lil more on top end. Makes me wanna play with it some more but for now it's great👍👍👍
Just out of curiosity, you should try running without the grate.
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Just out of curiosity, you should try running without the grate.
I've been seriously thinkin about it. Elsinore is too close not to give it a shot.
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You got me curious, please post pics of the nozzle area. I have never actually looked at one. I'd like to see how difficult it would be.
Cheers,
Joe
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I dont think it will do anything. You arent spinning the prop any faster actually the more water to it might rob it. It takes energy to turn that prop in the panther in which case it is limited on how it proforms before it cavitates. Thats exactly why a Berk or mixed flow is more efficient than a Axial flow pump. More water or more power and it works even better in the mixed flow setup
You might try something and think it helped but I doubt any difference is made
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Yes Axial pulls harder out of the hole cause it uses more volume but you can help that on mixed pump by being able to have increased torque
Okay Ill get off the soap box. Nothing wrong with a Panther but your not gonna surprise anyone with 1 either.
Panther will probly last longer rebuilt timewise than a Berk though :beer:
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The Panther does not like to be restricted on the outlet. I would think a diveter would absolutist kill performance unless it had a huge nozzle.
I could be wrong.
GT
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I dont think it will do anything. You arent spinning the prop any faster actually the more water to it might rob it. It takes energy to turn that prop in the panther in which case it is limited on how it proforms before it cavitates. Thats exactly why a Berk or mixed flow is more efficient than a Axial flow pump. More water or more power and it works even better in the mixed flow setup
You might try something and think it helped but I doubt any difference is made
One test is worth a thousand theories.
A pump won't cavitate from RPM. Cavitation is the result of low pressure areas forming and allowing the water to gas off. Pseudo cavitation is the result of starving the inlet of the impeller.
Anything present in the flow path disturbs the laminar flow. The turbulence at the inlet of the impeller causes cavitation. Cavitation, however, will allow the engine RPM to increase.
Efficiency of a pump design, mixed flow vs. axial vs. true centrifugal etc., is based on shaft speed. Axial flow pumps like and require more RPM to operate in their efficiency range.
Regardless of the pump design, jet boat pumps need to be fed water. All disturbances into and through the pump need to be minimized.
As far as testing, we are very meticulous. Just about every boat is equipped with an Edelbrock QuickData2 and is run on a track where back-to-back compressions can be made and evaluated. I released six inducer designs that we have been evaluating over the last two years, all of which have consistently shown a substantial improvement over the current design in 7, 8, 9, and 10 second boats. Don't take my word for that, it is better that you hear it from the guys who actually have the seat-time and the time slip to prove it.
I'm just trying to help brotherman. I freely share what I know. Bottom line, it's YOUR boat and your decision. If I can help in any way, I love to go spend a day at the lake testing.
Cheers,
Joe
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The Panther does not like to be restricted on the outlet. I would think a diveter would absolutist kill performance unless it had a huge nozzle.
I could be wrong.
GT
What about wedges? Does its design even lend itself to that addition?
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One test is worth a thousand theories.
A pump won't cavitate from RPM. Cavitation is the result of low pressure areas forming and allowing the water to gas off. Pseudo cavitation is the result of starving the inlet of the impeller.
Anything present in the flow path disturbs the laminar flow. The turbulence at the inlet of the impeller causes cavitation. Cavitation, however, will allow the engine RPM to increase.
Efficiency of a pump design, mixed flow vs. axial vs. true centrifugal etc., is based on shaft speed. Axial flow pumps like and require more RPM to operate in their efficiency range.
Regardless of the pump design, jet boat pumps need to be fed water. All disturbances into and through the pump need to be minimized.
As far as testing, we are very meticulous. Just about every boat is equipped with an Edelbrock QuickData2 and is run on a track where back-to-back compressions can be made and evaluated. I released six inducer designs that we have been evaluating over the last two years, all of which have consistently shown a substantial improvement over the current design in 7, 8, 9, and 10 second boats. Don't take my word for that, it is better that you hear it from the guys who actually have the seat-time and the time slip to prove it.
I'm just trying to help brotherman. I freely share what I know. Bottom line, it's YOUR boat and your decision. If I can help in any way, I love to go spend a day at the lake testing.
Cheers,
Joe
Joe,
While I agree 100%on a centrifugal pump, an axial pump has a completely different set of characteristics.
If you restrict a centrifugal pump, the turning load drops. If you restrict an axial pump the turning load increases. This is the one drawback to the axial design.
You can definitely over speed an axial because the is no sealed shroud to contain the centrifugal pressure. The center just does not get fed. Meaning the faster it spins,the less bite the blades have, the higher the rate of cavitation.
I think wedges would work as long as the outlet size of the nozzle is not effected.
But like you say, the intimate proof is in performance testing.
Not meaning any dis. Just trying to help with how these things work.
I am searching for an article I read years ago, unfortunately it is on this stuff called paper. Lol.. I have not been able to find it on the Web.
GT
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I cannot find the book I was looking for. Have to make due...
Here is a mixed flow pump curve, pay special attention to the BHP (brake horsepower) line.
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fwww.fwwebb.com%2Fimages%2Fpumps%2Fsupport%2Fsect_a8_fig06.gif&hash=bcd76dfb3b681b27c3d418ad108bfe0ea6e4e2bb)
Here is an axial flow pump curve. Again, check out the BHP as the head goes up... Crazy...
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fwww.fwwebb.com%2Fimages%2Fpumps%2Fsupport%2Fsect_a8_fig07.gif&hash=c0f0ce98fef3b6e65d0e4f442d291940228dedb2)
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I'd post a pic of the chart I use but I don't think anyone wants to see a pic of my ass in the seat LOL, I'll post up some pics of the pump and intake in just a bit for shits and giggles, and thank you fellas (flusher) and (gt) for all the info, I love reading and understanding as much as playin around with it.👍👍
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Here's what I've got..🍻
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Thank you guys for the info on the panther although some must be a little over my head it's pretty neat. It's super strong out of the hole and just falls off on top end.
BAM!
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Joe,
You can definitely over speed an axial because the is no sealed shroud to contain the centrifugal pressure. The center just does not get fed. Meaning the faster it spins,the less bite the blades have, the higher the rate of cavitation.
GT
It still sounds like a feed problem. I am not saying that you can’t over-speed a particular pump design; I just don’t feel that that is the case here. I have worked with Skat-Trak considerably over the last twenty years. Currently, the racers that they support are turning axial flow pumps in excess of 16,000 RPM with engines producing around 600 horsepower. Over-speeding doesn’t seem to be a problem there.
“Optimum geometry of pump rotors is primarily influenced by the specific speed (Rotations Per Second) or (angular speed of the impeller in radians per second)” (McGraw-Hill Pump Handbook, 3ed, P. 28).
“Outside the Specific Speed range shown in Figure 3 for each type of rotor, the efficiency becomes unsatisfactory in comparison to that achievable with the configuration shown for this Specific Speed” (McGraw-Hill Pump Handbook, 3ed, P. 29).
I really like this video, https://www.youtube.com/watch?v=K_w3gcvA87I (https://www.youtube.com/watch?v=K_w3gcvA87I)
Timestamp 7:05, illustrates my point about how increasing suction pressure will reduce cavitation. Increasing suction pressure also increases bowl pressure and thrust. I would suggest spending some time optimizing the transition from the hull into the impeller.
Timestamp 8:59 illustrates the disturbance in flow behind each of the bars in an intake grate. This can actually damage the pump. From a performance standpoint, maximum inlet pressure can not be achieved with a rock grate. If each of the bars is 3/16” thick, that is an 1-1/2” of blockage in a 6-7/8” opening. I would seriously look into making a loader.
Just some thoughts.
Cheers,
Joe
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It still sounds like a feed problem. I am not saying that you can’t over-speed a particular pump design; I just don’t feel that that is the case here. I have worked with Skat-Trak considerably over the last twenty years. Currently, the racers that they support are turning axial flow pumps in excess of 16,000 RPM with engines producing around 600 horsepower. Over-speeding doesn’t seem to be a problem there.
“Optimum geometry of pump rotors is primarily influenced by the specific speed (Rotations Per Second) or (angular speed of the impeller in radians per second)” (McGraw-Hill Pump Handbook, 3ed, P. 28).
“Outside the Specific Speed range shown in Figure 3 for each type of rotor, the efficiency becomes unsatisfactory in comparison to that achievable with the configuration shown for this Specific Speed” (McGraw-Hill Pump Handbook, 3ed, P. 29).
I really like this video, https://www.youtube.com/watch?v=K_w3gcvA87I (https://www.youtube.com/watch?v=K_w3gcvA87I)
Timestamp 7:05, illustrates my point about how increasing suction pressure will reduce cavitation. Increasing suction pressure also increases bowl pressure and thrust. I would suggest spending some time optimizing the transition from the hull into the impeller.
Timestamp 8:59 illustrates the disturbance in flow behind each of the bars in an intake grate. This can actually damage the pump. From a performance standpoint, maximum inlet pressure can not be achieved with a rock grate. If each of the bars is 3/16” thick, that is an 1-1/2” of blockage in a 6-7/8” opening. I would seriously look into making a loader.
Just some thoughts.
Cheers,
Joe
Don't get me wrong. I agree with you to a certain point.
Tie the boat to a stump and it will illustrate what I am referring to.
You can totally get away with it on a PWC because of the lack of parasitic drag/weight.
On a hull such as these, the performance is limited more readily. Not saying it can't work much better, just saying the design itself is the limiting factor.
As long as the velocity of the water versus the impeller pitch/rpm does not have a large delta, it will continue to have more performance left in it.
GT
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Tie the boat to a stump and it will illustrate what I am referring to.
GT
At some point, any pump will run out of water if not properly fed. Dynamic pumps are not known for their suction characteristics. I have seen that quote before, regarding how a jet boat will produce full thrust while tied to a stump. I am willing to bet that; if that test were performed with today's horsepower, the engine would just bounce off the rev limiter because the pump can discharge more water than it can draw in. Any pump system can benefit from increased inlet pressure. If the pump starts to pull the engine down, more work is being done. Then it becomes a matter of horsepower. Granted, I am not familiar with Panther or Jacuzzi axial flow pumps, common detailing techniques will still affect beneficial gains. If this were equipped with a Skat-Trak stainless impeller, it could be re-pitched to tailor its characteristics to the power curve of the engine. Unfortunately repitching a cast aluminum impeller is not an option. Regardless, I just can't buy into the concept of cavitating the pump to gain RPM.
The next thing I would focus on would be, should the OP be ambitious enough to pull his pump apart, is detailing the impeller. That will make a world of difference as to how the impeller will bite. I would thin and sharpen the leading edges on the back, or pressure side of each blades. Then thin and sharpen the trailing edges on the front of the blades. I would remove the radius where the leading edges intersect the hub so that the leading edges intersect the hub at a right angle. Be careful not to thin the blades too much towards their root to prevent cracks from forming.
I would then detail the bowl. Remove all casting flash. Sharpen the leading edges of the bowl vanes, again on the pressure side. Without seeing the bowl, I can't make a recommendation as to where material should be removed, but the trailing edges should be thinned and foiled.
Finally, I would assemble everything with the tightest clearance feasible.
If it was mine, I would remove the divider in the steering nozzle. If you don't want to remove it entirely, I would sharpen both the leading and trailing edges of that divider. Some will argue that it aids in steering, but I feel it is an unnecessary restriction.
I think a very nice job was done on the rock grate. I would still remove every other bar if you can't bring yourself part with it entirely. Although I would be more inclined to leave just three or even just one.
After looking at your pictures, should it be necessary, I believe it is entirely possible to make angle shims to be installed between the bowl and the nozzle adapter (droop) so the water isn't breaking over the bow like a super tanker underway full-ahead.
I have never seen a Panther at the races, but I believe that there is performance to be tapped.
Yours in max performance,
Joe
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What about a speed loader for it?
BAM!
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What about a speed loader for it?
BAM!
Absolutely, however I am not sure where you could source these.
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How hard would it be to get one for a Barkley and just fab it to fit the opening?
BAM!
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How hard would it be to get one for a Barkley and just fab it to fit the opening?
BAM!
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How hard would it be to get one for a Barkley and just fab it to fit the opening?
BAM!
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How hard would it be to get one for a Barkley and just fab it to fit the opening?
BAM!
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How hard would it be to get one for a Barkley and just fab it to fit the opening?
BAM!
Charles?
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I guess I should ask first, does the rock grate bolt into aluminum or fiberglass? If it isn't attached to something substantial, it will rip right out and crash the boat. Most likely that will kill the occupants.
There is a heavy liability producing loaders. B1racing carries product liability insurance and uses professional welders skilled in welding 4130.
If you are still interested, you would need a loose intake to match the profile of the uprights to. It is possible to do that in the boat if necessary. Need dimensions for the pad off of a rock grate or intake. The ramps should be located about half way fore/aft in the opening. The contour of the ramps should approximate the centerline of the intake and suction. The ramps should be about the height of a straight edge laying across the opening on the intake. This would give you a good place to start.
Then you start testing.
It is a lot easier to start with a clean slate than to modify a Berkeley. If it is in a ski boat, it doesn't need to be 4130, mild steel is fine. I wouldn't expect mild steel to live very long making 100 MPH passes though.
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It bolts to glass, I'll sharpen the nozzle divider and give that a go, I've pretty much sharpened every other edge that would cause drag, it doesn't plow the bow but it would be sweet to free it up a bit. Here's a pic at wot
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Granted this is all in fun, and it's really just a family boat, I'm not lining up with anyone but my buddies, I'm just playin around with it on basically a zero dollar budget lol.
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Why would it matter what it was bolted to if you put better hardware in it and go all the way threw the haul?
BAM!
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Why would it matter what it was bolted to if you put better hardware in it and go all the way threw the haul?
BAM!
The hydrodynamic forces against the loader are tremendous. Enough to crack two 3/16" uprights made from 4130. That would easily pull through fiberglass. When it fails, the boat crashes. For this reason, loaders should be inspected frequently. I am actually surprised that there haven't been any failures of the intake.
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Makes sense thank u guys! I'll just save and spend the money to put a Berkeley in it doesn't cost but a little more then an exiter kit. Sounds like the best bet to me.
BAM!