Custom made volkswagon powered 8x8 with sea doo pump

[chris davison]

Hi Ray its nice to here from you again and remember the absouloute professional job you did on the bushwacker. I think you might have me confused with Howard Hoover though, he is the one who hurt his back remember he is the one with the locker in his auto transaxle. I really wish he could finish his build. Im using the same tires you used but 27" tall since the axle centers are 27.5" I really wish I had a little less front end hanging over the front tires but with this setup I can prob. hit the water at 25 mph one switch and the pump is spinning. I have a setup just like a sand rail stock bug peddals with brake that works thru a sand rail turning brake the push to brake one side and pull to brake the other side hooked to the stearing wheel and the cable from the pump steering hooked to it also. So when I push the brake peddal both disc. start to brake but using the steering wheel only one at a time can be applied also moving the pump steering.

[chris davison]

Two more pics in the gallery of todays work with the motor in and the gas tank mounted also the turning brake is in the pic

[Bw6]

Hi Ray its nice to here from you again and remember the absouloute professional job you did on the bushwacker. I think you might have me confused with Howard Hoover though, he is the one who hurt his back remember he is the one with the locker in his auto transaxle. I really wish he could finish his build. Im using the same tires you used but 27" tall since the axle centers are 27.5" I really wish I had a little less front end hanging over the front tires but with this setup I can prob. hit the water at 25 mph one switch and the pump is spinning. I have a setup just like a sand rail stock bug peddals with brake that works thru a sand rail turning brake the push to brake one side and pull to brake the other side hooked to the stearing wheel and the cable from the pump steering hooked to it also. So when I push the brake peddal both disc. start to brake but using the steering wheel only one at a time can be applied also moving the pump steering.

Hi Chris, thanks for the kudos. Yes I do have you confused with Howard, sorry, the similarity of the builds, caused the confusion. I haven't corresponded with him for a long time, but as you hope he finishes his project. But I understand how you can lose your momentum, it is hard to stay motivated, especially if a project is drawn out over months or years. But the satisfaction of completion makes it all worth it.

I like how you intend to steer both your AATV and the jet pump, it should be very effective. What rpm do you intend on spinning the jet pump? I always had a goal of 10 mph. and worked on a number of different concepts to achieve that but so far have been unsuccessful. It's hard to fight physics, especially the fixed hull speed for displacement hulls. But I think you may have a chance with the long front, it may give you a semi-planing hull, that may allow you to climb out of your bow wave. The tires will cause a lot of drag, as you know, but you have a pretty good shot at it, IMO. Looking forward to see your progress.

[chris davison]

Hi Ray
My project was stalled for a while and now I have changed Jobs and do not have access to a lathe or milling machine.
Have some cash now so can do some and most of the high $ items are already purchased. I looked at your BWII walk around, very impressive what speeds did you achieve on the water with the twin props and did it steer very good with these? Ive always wondered if you could put a hyd pump chained to the axle chains and hook it to a hyd motor for water propulsion just put an elect sol. normally open between the inlet and outlet of the pump so the oil just goes in circles til you close the sol with a switch then it can only flow thru the motor and back to the pump.
The stock vw is capable of just over 4000 rpm and I think most of the seadoos have a rev limiter at 6200 rpm or so The engine I have puts out 53 hp and 78 fpt at 2600 rpm Since it will be belt driven with a 1.5: double cog belt I will start with a 1:1 ratio and see if I can go higher. My biggest problem is the impeller on the pump goes the opposit direction of the vw motor crank shaft. I bought this sea doo pump from a guy who had already put a racing impeller in it so it is suppost to grab more water per rev. than stock this could help with lower rpms. I dont think I could plane even with a 100 hp motor to much tire drag. I will also weld on a reversing clam shell on the rear of the boat for reverse in the water.

[Bw6]

Hi Ray
My project was stalled for a while and now I have changed Jobs and do not have access to a lathe or milling machine.
Have some cash now so can do some and most of the high $ items are already purchased. I looked at your BWII walk around, very impressive what speeds did you achieve on the water with the twin props and did it steer very good with these? Ive always wondered if you could put a hyd pump chained to the axle chains and hook it to a hyd motor for water propulsion just put an elect sol. normally open between the inlet and outlet of the pump so the oil just goes in circles til you close the sol with a switch then it can only flow thru the motor and back to the pump.
The stock vw is capable of just over 4000 rpm and I think most of the seadoos have a rev limiter at 6200 rpm or so The engine I have puts out 53 hp and 78 fpt at 2600 rpm Since it will be belt driven with a 1.5: double cog belt I will start with a 1:1 ratio and see if I can go higher. My biggest problem is the impeller on the pump goes the opposit direction of the vw motor crank shaft. I bought this sea doo pump from a guy who had already put a racing impeller in it so it is suppost to grab more water per rev. than stock this could help with lower rpms. I dont think I could plane even with a 100 hp motor to much tire drag. I will also weld on a reversing clam shell on the rear of the boat for reverse in the water.

Hi Again, Nothing like cash, to help motivate a guy! BWII's props weren't that efficient because they weren't below the hull, but they did work and directional control wasn't all that bad. I only got around 3 mph. I had a design that would have worked better by lowering them below the hull, and retracting for land, but it required more time and money. The problem with props is you need an auxiliary drive either mechanically or hydraulicly to get the rpm to it justice. A double crankshaft engine would work when coupled to a clutch/gearbox or a hydraulic pump/motor would do the same. You may be surprised what 4,000 rpm will do though. Yes tires, what a drag! (no pun intended), but the more I work around these things usually the best solution is a compromise. No one machine has it all. Your "Walley" looks like it will lean towards safe decent water travel, and pack a decent payload, looking forward to seeing your progress.

[chris davison]

Safe decent water travel is partially what I designed it for with 24" of verticle side I have done the calcs. for bouyancy and it comes out to 6000lbs to sink it to the lip. 1300 lbs should put it at 4.3 " into the water again I dont know what the tires will add in either direction. but at least the pump will be submerged. I want to build a hood over the front bow maby 12ga. aluminum to cover it and improve the looks hinging with a couple spring shocks to help keep water off legs in the front.

[chris davison]

Wow with the engine installed I still have a good 20 inches from the rear pully to the sea doo pump housing. Bored a hole for the pump drive shaft thru the rear of the hull and installed the shaft its to long and will have to be shortened. Fabbed a dash board and will install the stock VW speedometer and my fish finder need to buy some more metal and bolts though. Any questions? any suggestions?

[chris davison]

Here is a good pic of the engine install

[mudbug3]

chris davison

I was surprized at how much room you still have with the VW motor in it.

[chris davison]

I was also happily supprised , Didnt remember that it is only 14.5 inches long still have to add a timming belt pully to the fan pully then go to clutch and shaft then to the pump drive thats the shaft you see from the rear towards the engine.