Amphi-Cars - What would you have done? : LUSENET : Junkyard Wars : One Thread

We've all watched the amphi-cars challenge. Question: If a 4wd vehicle was not available (too convenient), describe the machine you would build.


-- Max (, March 27, 2001


Also: It appears that automobiles are the major focus for most "vehicles" built. It would be nice to see a larger variety of "junk" in the yard... more batteries and electrics, smaller gas engines, etc.


-- Max (, March 27, 2001.

I would have used a light front wheel drive car and applied the many oil drum theory to provide flotation.

After making sure the engine ran (ouch) I would have used a smaller engine (motorcycle etc) to drive a prop. The rudder would be mounted on a tilt mechanism that would allow the rudder to come out of the water on the ground. Possibly, a small wheel to push the rudder up as it moved along the ground.

If no other engine were available to drive the prop then I would have mounted a chain drive sprocket to the front wheel drive axle to transfer power to the rear.

-- Michael Blizzard Toxic Avengers (, March 27, 2001.

I think a 4 person, pedal powered, vehicle would have worked well. If there were 4 bikes in the yard and chain. A quick paddle wheel system could have been made with a chain drive. Probably 2 pontoons. Not out of 55 gallon drums. Something smaller since the overall weight wouldn't be as much. Light weight and fast. No spittin and sputterin engines.....

-- Duane Flatmo, Art Attack (, March 27, 2001.

Too bad really, had the losing team mounted that engine a bit higher and replaced the front wheels with one steerable wheel-rudder... may have worked. I'm guesstimating that the van top could float close to 3000 pounds... why even bother to remove the engine from the car, simply smoke all that was not required and weld it on.


-- Max (, March 27, 2001.

That would have been EXCELLENT... a Peddle Powered Ultra Light vs Monster Land Rover vs Swamp Boat.


-- Max (, March 27, 2001.

Well I most definently would not have crashed it right off the bat!!!!!!

-- Drew Jaeger (, March 27, 2001.

I've mentioned this before, and i think it bears repeating...

Look at the tape closely. See all that water sloshing around and around the front wheels? See all that wasted energy? Think: how can i get all that water moving in one direction, and maybe get some thrust out of it?

Also note that one could have converted the sides of the rim to a paddle wheel setup.

You get a challange like this, don't make me BOO you. ; )

-- Mighty Mik (, March 27, 2001.

yes but if you look closely there would be no room to steer if you add paddles

-- northern stars (, March 27, 2001.

I would have used a traditional small car on drums...

I would have made removable rudders on the front tires (removeable from on top the car. And I would have welded another set of rims on the outside of the drive rims with paddles on them...

-- Dan Denney (, March 27, 2001.

To make temporary paddle wheels for a front wheel drive car with the body removed, first put screws into the beads on a pair of big wheels and tires. Then let out the air, and slice them with the fiber wheel saw, so that they form rubber blade paddle wheels which can be welded to the original front wheels with short spokes of pipe or rod. Remove the rear axle, which would replaced with one steerable (motorcycle?) wheel, then make the whole works float. The original tires would support it on land, and the paddles would work in the water. For steering in the water, a rudder could be attached to the steerable rear wheel, like a long box around the tire with the tire sticking out the bottom far enough to work on land. The air boat would have been the faster machine had it been build with better steering, a little more planning and luck. The Royal Navy team just didn't want to get wet. It wasn't bad for having never seen an air boat in action. One of my redneck buddies drove his air boat to the bar on the trailer one night when his wife hid the keys.

-- Waddy Thompson (, March 28, 2001.

A front wheel drive car with airplane prop. mounted at front.. on the crank (or simply replace the rad fan with the prop) would have been an interesting start to a prop/wheel propelled "boat". Had they welded tractor/bus/big wheels to the 2 car rims... they probably could have slid the van roof right under it. So many different options.


-- Max (, March 28, 2001.

If there had been a VW beetls in the yard this challenge could have been done in a couple of hours. Seal up the body, the doors, and the heater tubes. mount a bearing to the rear bumper, and attach a shaft and propeller to the crankshaft, a little waterproofing to the engine, and you are sailing.

We did this years ago, had a race track that included a small lake, never had one sink.


-- JustJay-captain-Three Rusty Juveniles (, March 28, 2001.

You're right. Pushing giant 55 gallon drum's head on thru the water without a cone shape in the front was not good. Also the prop was mounted down inside a slot. A prop won't work very good unless it has a clear area behind where all the trust can exit. That's why the water was shooting straight up like a water spout. It was still hellafun to watch!

-- Duane Flatmo, Art Attack (, March 28, 2001.

As far as the paddle wheel idea. A paddle wheel needs to just barely hit the water to get the best effect. If they're too far under the water, they just become counter productive. Possibly a fan belt hub mounted to one of the drive wheels with a belt drive to a jackshaft above the car , with a paddlewheel on both sides of the car and a rudder out back

-- Duane Flatmo., Art Attack (, March 28, 2001.

I love Jay's idea for the Amphiwagen(TM) Volkswagen conversion. It reminds me of a late-60's TV ad for VW which showed a bug floating in water and a voice over saying, "While a Volkswagen will definitely float, it will not float indefinitely."

Whatever happened to Doyle, Dane, Bernbach, anyway?

(... after a quick Web check, we find that they are now "DDB." You can see some of their famous VW magazine ads at

-- Rick Tyler (, March 28, 2001.

I doubt I would have went for paddles unless it was an ultra-light craft. Simple rotating paddles are far too slow and would require accurate depth positioning.


-- Max (, March 28, 2001.

Lyn and I have been talking about the paddlewheel idea since the first time this aired here around Thanksgiving. It would work, but would require a few mods. Slanted paddles would allow the paddles to go deeper into the water, but it would be much better to get the paddles further out of the water. You could also move the location of some of the barrels to make the craft sit higher in the water. The prop was a cool idea, but needed to be moved to the outside of the vechiles body as Duane said. Jay has the right idea. A bearing on the back bumper and a longer drive shaft would have been much more effective.

Brunella had to hold me back as I started screaming at the screen again, "Don't cut that prop, you IDIOTS! MAKE A HIGHER FRAME!" Anyone else would have grabbed a few of those scraps of angle iron and just made a bigger engine support??

-- Joey Falgout (Broadcast Junkies) (, March 28, 2001.

I believe they cut the prop because they were out of time, and the time they were given was certainly more than 10 hours. Cutting the prop certainly decreased their power, but it was not their downfall (steering). Before the prop began hitting the water, it appeared as if they had ample power.


-- Max (, March 28, 2001.

A quick re-design for the steering would be a single rear wheel

-- Andrew Walmsley (, March 28, 2001.

first of all find A light weight car, and A heavy duty rear end. cut the car in half. using the outer rims of the dual wheels make "paddles" since you have two, they don't need to be big. mount the rear end upside down so the rear wheels become the front wheels and drive "backwards" at the high ratio that truck rear ends run for torque, you would be able to spin the tires at about 1000 rpms, I think no matter how bad the design was, it would still have pretty desent forward momentum. also add lots of boyancy to front, and everybody sits at the back, this gives good angle for cutting through watter and it would lift the front so the paddles are not in the water completely. since I am sure that everybody has been doing their homework, STAY AWAY FROM THE VAN ROOFS they ALWAYS leak, and almost always sink or start slowing down by the end.

-- Robert (Team Bullwinkle) (, March 29, 2001.

Engine question - They mentioned the property of a diesel engine running "underwater" because of not needing plugs. Ok, I understand that and see that if you extend the air intake that it can be done.

Why is this not the same for a gas engine? If the plugs are submerged, why would this make the engine shut down? Of course, this presumes the same air intake issue as above. If you start sucking that non-compressable water into any engine, it stops very quickly.


-- Brian Flynn (, March 29, 2001.

I think the answer has something to do with all the electrical bits required to make a gas engine work: Points, plugs, condensors, distributor, coils, (or maybe just a black box CDI system), and wires, wires, wires. It would all have to be sealed and waterproofed, including every junction, to keep it from shorting out from water intrusion. I'm sure it can be done- just not in ten hours. Diesel engines rely on high compression (23 to 1, versus about 10 to 1 for gas) to generate the heat in the combustion chamber for ignition. No battery required- and no electrics either- AFTER you get it started. If you watch the Bodgers start their Land Rover Amphib, They only tough the wire to battery to spin the starter. After that, it was not needed. Electrics are a pain in a marine environment.

-- Chip Haynes (, March 29, 2001.

In our kinetic race alot of people try paddle wheels. Alot of them never work. There is a sweet spot in paddlewheel design. Just the right amount of water displacement. Just the right amount of depth and the right torque. Too much spin and the paddles churn the water instead of moving thru it. Look at steamboats on the Mississippi.... A good barometer!

-- Duane Flatmo, Art Attack (, March 31, 2001.

I believe we'll eventually see a "boats without props or jet pumps" challenge. A paddle wheel vs mechanised oar design. Its a safe challenge, lots of unique science involved, some history and the project could be completed in 10 hours.


-- Max (, March 31, 2001.

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