Laid Back Boaters

Well Since I aquired a Panther Jet exit housing, modified by Panther Jet, with their version of a Jetovator. I thought I would document it for any interested boaters out there. Thru-out last summer. I think I have my boat running as well as its going to the way its rigged. Its a 78 Tahiti SC, 20'6", uses a Ford 460 & spins the Panther pump at 5600 RPM's flat out. only engine mods are a mild cam. Specs are Int. dur. @.050" 220 (.490" lift) Ex. dur. @.050" 228 (.505" lift) timed straight up. Edelbrock Torker2 open plenum Intake, BG 750 CFM Mighty Demon Carb., Panther thru Hull exhaust (port matched) Distributor set at 12 degrees initial and 34 degrees total advance. The pump has been sleeved (Aluminum Bronze) and has the Hi Perf Setting of .015" Impeller Clearance to Housing. Through Out this experiment I will be using my stock speedo for speed. As of this writing with about 20 gallons of fuel and just me in the boat I can hit 58 MPH on my speedo. My main goal is to try and add the flexibility of driver adjustable trim (and rooster tail) without sacrificing any performance if possible.

Well my first trip on the water with the PJJ installed was a little disappointing. The Mods that were made to the steering nozzle made the boat very slow to react to steering input. The only position that seemed to show any improvement was all the way up. The main reason I believe is in the strait or down position the sides fo the nozzle actually impede the water flow. Heres a couple pictures. The yellow line is the edge of the exit housing to show its relationship to the stainless steel tubing that directs the water up or down.



this is the side of the nozzle marked with black that I am going to modify to give the water an easier exit path.


the sides of the nozzle seem to cause the exiting water to be forced around the tubing as well as through it.


you can now see the edge of the exit housing on the side of the nozzle I cut versus the uncut side.

I am going to weld back in a 2" deep by 1/4" thick plate in the center of the modified steering section to better control the steering. Here is a picture of the Panther modified one.


Why they whacked off a 3"x3"x1/4" chunk of the directional fin has yet to be established. So I will see the reaction from giving it back a little more directional control then it has at present.

Steve,
The directional fin needs to be modified to give the up/down nozzle the clearance needed to move. You're also right, to a point, about the water being able to flow on the sides of the insert. The thing is, water will flow to the area of least resistance which means it will flow through the bigger opening of the nozzle. The water that gets around the insert will end up moving much slower and then in essence will cause a blockage of sorts.
I do like the mods you did to the insert and you will find it does make a bit of a difference. You should also be able to take a little material off the top of the exit side of the nozzle to get a little more height in the tail.

BTW, Kris has put his boat away for the winter so I asked him if he would loan that Panther droop to you so you could give it a try. Give him a call to arrange a way to pick it up. I guess I could have him bring it to the Christmas Party next weekend and I'll get it to you somehow.

Thanks Cas. That too would be interesting to try. The Mods Panther made to the steering housing were much more radical then needed. I also have a couple of other thoughts I may try on sealing the tube at least on its axis point with a couple of Viton or teflon rings. By cleaning up the sides of the tube, It should cut down the amount of turbulance it was creating at the joint. I think it would be pretty kool to be able kick up a kool rooster, while leaving the boat rigged pretty much as it was delivered. I do have one question though. this jetovator has 11 degrees of upwards travel from center. Do you know how many degrees of trim the Place Diverter gives the Berks? I will post some more pics as I continue to play with this diverter also.

for some reason I have 16º total travel in my brain, 8 up and 8 down but I could be wrong on that. I still doubt that there is going to be much, if any, turbulence in that area. If you think about how a river flows between say 2 rocks that are 2 feet apart, the water will be very slow on the backside where the water is hitting the rocks and very fast through the middle. There will be some water going around the opposite side of the rocks but it will still be a whole lot slower. I would think building up the inner lip to better direct the flow might be worth looking more so than a seal of sorts?

I tend to agree with you about the small amount of misdirected water. Heres my thoughts, and very easy to do. In this pic you see how just the top edge of the Tube meets the inside of the housing when trimmed.


If Panther would have cut the inside edge with more of a "Chevron" Edge, instead of a straight cut. This would make a much cleaner path. I believe. Heres a picture of my idea.

With the tube shaped like my drawing, in full trim I would now have 1/2 of the tube against the inside edge vs only 1/4 of the tube against the inside edge. Any way I look at it. This should be a much smoother transition for the flow of water then bouncing off of 3/4 of the tubes leading edge to about 1/3 of the edge, and I will also taper each side (chevron shapes) to be thinner at the leading edge. So I am making 2 stainless wedges to weld to the tube, lets see how they come out.

I also dug out out my protractor and a short steel rule to see how many degrees of trim this nozzle has. The way that it is setup by panther looks to be about 11 Degrees of UP Trim from level and about 10 degrees of Down Trim. I took a look at Place Diverters website and they mention that their diverters offer 40 degrees of total trim! Wholly Crap! So instead of trying to figure out where to get another 8 degrees of travel. I will just weld a little bead on the bottom on the exit side of the tube, Take my trusty old die grinder out and give it juuuust a little lip to persuade the flow to kick up just a little. As a side note if after playing around with Panthers version of this device proves to not meet my expectations. I will find me an old broken berk pump, whack about the last 3" off of it, and weld that sucker on the end of this exit housing As long as I use a diverter/Steering nozzle with at least a 3 1/2 " throat, It would stand to reason that it should pass as much water as a stock panther exit , right? Hmmm... I wonder if Tom at JBP has allready tried it, and what his testing showed.

that looks like a whole lot of good thinking there Steve. It's going to be interesting to see if it makes much of a difference. I really like the chevron edge, seems like it ought to do the trick for sealing it all up better.
ADM Boat Works in SoCal has been doing the chop and weld (actually bolt on) thing with the Panthers for quite a few years. I've heard good and bad, mostly bad with that particular conversion as it changes the way the pump flows due to the additional pressure it causes. An yes, there has been some with larger nozzle sizing to go along with it. If you have an extra Panther hanging around, give it a whirl and test for yourself but it seems like an awful lot of work for something that may not give you any benefit but could hurt. It will give you some first hand knowledge though.

I seen this and dont know if this would help you? Its a Panther jet-a-vator but it looks real close to a place diverter. Its on ebay heres the listing http://cgi.ebay.com/ebaymotors/diverter ... arQ5fParts

and heres the picture

Wow, Dave. Thats kind of interesting looking? I'll go see what its up to. Cas, my thinking on a place diverter style steering/trim unit. plus reverse has got to work better than the Panther one does. I think it Would only be viable on a Panther if you didnt choke it down (IMHO) its kind of challenging,(because its axial) but as long as I keep the dimensions of whatever mod I try, relative to volume, not pressure. It stands to reason (haha, I just re-read that statement) that a small gain here and a small gain there, should at least add up to a pump thats better than the original. LOL, maybe only very minutely, but nevertheless, BETTER! Now, with bait on the other hook. I am real curious what effect that droop unit you have, does to a Panther. Even if any of these changes dont increase performance of the drive, They must at least make it act different. wouldnt ya think?

And if nothing else, I'll have even more info for the next Panther Pavillion (if there ever is one) I love trying things out, my time is really my time, and I love boating , so let the chevron mod begin!

Hey Dave, I couldnt get the link to come up on EBay. Do you have another link I can Try. I wouldn't mind sending an email to the person who has that piece and see what results he had, if any. Thanks, SMac

I wonder if that thing is as big as I think it is? The exit tube of the Panther one I have is 3 1/2" X 3 1/2" square stainless tubing. If that bolts up to a Panther, thats gotta be like a 5" OD Casting. Hmmmm.

Steve,
That's why I suggested you give it a try on your boat but I do know what many others found out with doing the same thing, some good and some not so good. The big difference is you can do the mods yourself and not have to pay someone else to do them. Being that I rebuilt these things for a few years, I've seen a lot, heard a lot and done quite a bit although I didn't play around too much with the Panther diverter as it worked rather well on my own boat.
There was one person that even extended the Panther nozzle and made his own diverter that slipped over the nozzle instead of having the diverter on the inside. His worked out pretty good but sure was ugly as all get out. I know he was working to make it look better and was also trying to make it so it was an easier install but haven't heard anything about that in over a year.
So far, each boat that the droop was installed on had different results so you will need to give it a whirl to find out what effect it has on yours. I'll see if Kris can bring it with him to the Christmas Party today. Maybe we'll pass it off to fleetimus and you can get it from him unless 454blueboat shows up then he can take it. I spoke with Scott yesterday and he and Tammy are pretty sick, don't know if they'll be coming to the party.

I found it Dave! Thanks for the lead! guy wants $100 for it. sounds like a deal if it is as big as I think it is.