86 js550 with 140 pump in a stock cavity

rhaas · 11-24-2009, 09:13 AM

I figured out how to do a 650 pump in a js550 hull without grafting in a pump section. This is not a conversion for the masses, as it makes use of MANY custom part in order to make it work, but it is possible. I am going to include pica of where I am at but don't expect the build to be done anytime soon, I have two little girls and a house I am finishing up. lets start with a pic of the ski before the conversion started. It was a 550 mod motor and a 440 pump the engine had less than 5 hours on it and I never even ran the 440 pump and then hurricane Katrina hit. this is what tyhe ski looked like before and after the hurricane. you can barely see the ski after the storm with all the debris in the way, but lets kust say it was a total loss.

rhaas · 11-24-2009, 09:22 AM

The hull was stripped down to bare bones in an effort to salvage anything, and work was being done to bring it back to the modified 550 that it was. but then this site gave me inspiration and the plan changed to a 550 with a 750 small pin and a 650 pump. First step was to add costom sponsond that I designed and machined myself out of solid rigid foam and glassed over. Keep in mind that I am a design engineer and run and program for a cnc machine shop so my limits are my imagination. here are the sponsons epoxied on and glassed over.

rhaas · 11-24-2009, 09:23 AM

these were then smoothed out and painted. I also made a new exhaust outlet from billet aluminum.

rhaas · 11-24-2009, 09:28 AM

the next step was to fit the 650 pump in. this required a lot of cutting so I used a pummp with a junk liner in order to do some testing, but it turned out good so I removed the liner and installed a fiberglass liner, then machined the clearances on a lathe. I adapted the 650 pump to a bulkhead mount and designed and machined a custom pump shoe out of aluminum. I dont have any pics of the shoe prior to installation but I do have a screen shot of my cad file.

rhaas · 11-24-2009, 09:33 AM

to my surprise the 550 pump cavity is almost exactly the same size in diameter as the 650 pump internal. This setup actually sets the pump back about 2 inches. So I used a x2 driveshaft to get the right distance for the bearing block assembly. The stock 650 bearing assembly doesn't fit the js550 bolt pattern so I machined my own. I will get pics of this up later. With this setup There are no alignment problems, the pump cavity forward wall is lined up at almost exactly 90 degrees with the driveshaft. After I installed everything to fit it was only out by .1 degree. Not bad. I will get some more pics of my progress in the next few days, I have some time off for thanksgiving and will upload some more pics at that point.

Mirage14 · 11-24-2009, 11:19 AM

You have my attention

. I can't wait for the next update.

Man those pics of the Katrina damage brought back memories. I took S&R teams from PA to the area 5 times after Katrina hit. The devastation was total, and un-explainable to anyone that was not actually there. Was the Porsche caught up in her wrath too?

We stayed in Bay St Louis at Gods Katrina's kitchen while we worked there. I would sit on the white sands of the beach at night just to turn my back on the all devastation. We worked in areas that from the Bayou, to Biloxi, and that experience alone change us forever.I know your pain. I hope you are doing better now.

John S.

rhaas · 11-24-2009, 11:24 AM

that porsche is post katrina, but I lost a 76 911 time trial car and a 74 914 modified autocross car. you can see the 914 in the pic it is next to the house behind the boat. All you can see is the hood popped up. I pretty much lost eveything I own in the storm. The structure of the house is all that survived. I lost all my belongings.

Mirage14 · 11-24-2009, 12:12 PM

I am sorry to hear that, but I knew that from your location. That is all I saw there. Everything was a total loss. Like I said unless you were there, there is no way to convey the damage and heart ache. I must admit, after 5 days there, I broke down and wept like I never have before. We all did. There is only so much of that you can take. I don't know how you made it through. I hope you are doing better now. I was amazed in the first pic that the skis did not get swept away. Sorry about the cars. Is Bay St Lois recovering?

the WaTeRhAwK · 11-24-2009, 12:21 PM

subscribed.

Mirage14 · 11-24-2009, 12:30 PM

opps, sorry about getting off the topic. I love the mod!