Custom made volkswagon powered 8x8 with sea doo pump

[chris davison]

Mike ask me to start a new thread so here goes guys I think I have Pics of every stage of construction and even diagrams of the drive train.

When I decieded to build this vehicle I essentially wanted an 8 wheel drive boat that was not nose heavy ( engine in front) and have no fears in the water or braking on down hills would carry 4 people and all the camping gear (good payload) and I could fish from all day long and not worry about a windy day on the lake. Oh yea I did not want to depend on the tires for propulsion on the lake. I wanted a vehicle to drive across a lake for miles drive up on the shore and camp or 8x for some more miles to camp or hunt.

This is what I have come up with, having built several sand rails I had formed 4 c channels 10 feet long 5 inches tall from 10 ga. steel to form the lower frame for axle bearings. On top of this I made a 2" tube frame .095 wall thickness with all the diagonal cross bracing. Then I bought 3 sheets 5x10 feet of .092 aluminum had them bent to my specifications then welded for 8 hrs with a spool gun. When I put the frame in the alum tub I had to push it down with a fork lift with 500 lbs on the forks good tight fit.

Its 13.6 feet long and 72" wide the bottom section is 48" wide with 11" fenders each side. The entire edge is caped with 3/4 alumin. conduit. I have a sand rail 11 gal. spun alum. gas tank. The seats move on a rail and clamp down to where its comfortable and will lay flat also. The cushings I will have sowed will attach with velcrow so they can be removed to go under sleeping bags. there is also a roof rack for the lighter things like sleeping bags tent chairs etc. Eventually I will build an amphib. trailer also to pull.

[Mike]

Chris, that really is some great looking metal work. Please upload some more pictures of it to the gallery when you get a chance. I would love to see more, including some interior shots, pictures of the motor, transmission, frame, etc.

Immediately I have a ton of questions but I don't want to overload you so here's a few:

Is it complete or are you still building it? Also, have you been able to test it out yet?
What kind of speeds do you get or calculate that you can get with it on land and in the water?
What kind of transmission are you using?
Is it chain driven?
How are you engaging and disengaging the pump?

Thanks for starting a new thread. That is a unique project that looks like it would suit your needs perfectly.

[George]

Looks pretty cool Chris!

[chris davison]

added thumbnail links by copying the code below each picture and pasting it here

Mike
No it is not complete yet and not tested, the vw bug will do about 72 mph on flat ground and it weighs 1850 lbs. so I estimate my rig will weigh in at 1300 lbs and do about 35 mph Im hopeing for about 12 mph on the water or more. Remember the vw trans axle is a 4 speed transmission with the rearend in the same housing 1st gear is 3.8 ratio and the ring and pinion is 4.125 ratio, the axle shaft to jack shaft is a 2.1 ratio so with 78 foot pounds of torq from the motor a stock vw bug should get 1222.65 foot pounds of torq at the axle but I have a 2.1 reduction to this so I should have 2445.3 fpt to axle.
Yes it is # 80 chain driven. Im hopeing to direct drive the pump from an air clutch I purchased on ebay it handles 1365 inch pounds torq at 80 psi air. If this cant be done I will drive it Hydraulicaly with the clutch on the hyd. pump input shaft and a hyd motor on the sea doo pump.
The trailer is hand built also with tilting ramps that stay down when you drive off and when you drive back up on them they tilt with shifting weight and latch automatically it also has elect brakes. I have also a 12vdc 3000lb winch. to attach to the trailer or to the rig.

[mudbug3]

chris davison

I saw the picture of the inside of the tub of your aluminum 8x8 in gallery, and you have installed a very unique drive system.

[Mike]

That is going to be very cool. Be sure to update this thread with any progress you make. I look forward to seeing it completed and hearing your thoughts on how it performs.

[chris davison]

There is a couple more pics in the gallery now, one of the rearend and pump, the other is a good view of the inner steel frame transaxle disc brakes and jack shafts from the front seat looking toward the rear.

[Mike]

Here's the new pictures you just uploaded:



If you copy the code under the pictures and paste it into your post, they will show up automatically.

[chris davison]

I took the fan shroud off the motor in prep to cleaning it up for installation. Had to cut some metal out of frame for motor fit as I had no motor to measure when building frame had to do it from memory of what it looked like. Most of the work is very easy for me as I have been a certified welder, an electrician
a refergeration tech and Manufacturing process trouble shooter. Its time and $ that slow things down.
I moved from Calif to Ark. to support ageing parents and had to set up an entire garage shop on their property. But now finally Im back to working on "Walley" thats what we call this vehicle. My wife is just as enthustic about it as I am Having loved to drive the other projects I've built.

[Bw6]

Hi Chris, Glad to hear from you again. I don't know if you remember me, but we exchanged emails a few years back. Last I heard was you were going to sell your build, progress had been slow because you had hurt your back, and like most of us money was in short supply. Nice to see you motivated again. Looking forward to seeing "Walley" completed, I always liked the concept, and the components you used were first class.

Ray

[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.