The Misadventures of Quinxy truths, lies, and everything in between!

21Jul/121

The Journey of the M820



I picked up my 1971 AMC M820 Expansible Van from Mt. Vernon, IL this past week.  It turned out to be quite the little naive odyssey.

The outbound journey went relatively uneventfully, got a one-way rental to drive myself, Francine, and Osita (the dog) from Pennsylvania to Illinois.  After a thirteen hour drive spread across two days we met the seller, Wade, got to test drive the vehicle, bought it, and retired to the hotel to contemplate our next move.

Luxury It Ain't

Three major obstacles became immediately clear when I saw the vehicle and got to drive it.  The first problem was that the vehicle's cab was tiny.  There was arguably room enough for three lean soldiers with little to no gear and little to no leg room.  But two average folks and a dog would not fit easily.  The second problem was that the engine was deafeningly loud, the Army having made no effort to provide a quiet cabin.  The third and most serious was that Illinois happened to be in the middle of a record breaking heat wave and daily temperatures were reaching 107 degrees Fahrenheit.  An un-air-conditioned cab combined with a heat radiating engine and transmission was a recipe for disaster.  The fact that my dog is super fluffy and inappropriately keeps her winter coat on until September didn't help.  I knew I had to solve all three issues before we could start for home.

Where Does a Dog Fit?

There was only one place Osita would fit and that was on the floor board.   I put down a furniture moving pad and a dog bed to cushion the harsh metal floor and cover up sharp edges.  The difficulty was that she is a large dog and her body took up all the room of the passenger's floor as well as all the room in the middle floor.  Her upper body was wedged between the transmission's stick shift and the high-low transfer case shifter.  She had to keep her head up and out of the way whenever I needed to shift gears, which involved quite a lot of work on Francine's part.

Osita was a real trooper.  She would instantly find her place whenever I had to lift her back in, and she didn't move around at all once she settled.  I think it was all the practice in the motorcycle sidecar that touch her such patience for us humans.

Francine was an amazingly good sport for having to put up with very limited leg room and the constant need to keep Osita out of the way.

Silencing the Deafening Roar

For us humans the solution to the engine noise was easy.  We wore ear plugs.  Protecting Osita's hearing proved a little more challenging, and in retrospect I'm not sure how much good it did.

I bought Francine and Osita two pairs of the best headphones Lowe's had to sell.  Francine could wear hers without modification, but Osita's pair required some changes.  I removed the adjustable metal band at the top and replaced it with two straps which could be tightened or loosened with Velcro.  I also added a chin strap whose length could also be adjusted.  The system worked, but only sort of.  My primary concern was that her ears are vastly bigger than ours, and while I could (barely) fit her folded up ear into the headphone ear cup I couldn't imagine that it was pleasant, and I couldn't be sure that the seal was all that effective in terms of loudness protection.  I abandoned this solution in the end after a few short trials on the road.  They came off too easily and I was just too afraid it would hurt her ear cartilage if left on too long.  The only fallback I had available was to use human foam earplugs.  I did some Googling and saw people specifically recommending against their use, since human earplugs are smaller than what dogs would need.  Without any alternatives I decided to give it a try anyway, but instead of using just one per ear I would use two together in each.  This approach seemed to work and would stay put.  To what degree it eliminated the sound I can't be absolutely sure.  I know when I use a pair they can be finicky; they may seem to be in right and yet need adjustment to block out all the noise.   I felt somewhat comfortable, hopefully not foolishly, that her hearing would be protected because I had just a few days earlier read a passage in a book, How Dogs Think?, that mentioned  dogs having a biological mechanism by which they can protect their hearing from loud noises (environmental ones that they can expect, versus isolated and unexpected ones like gun shots).  If the ear plugs didn't do enough presumably her biology would.

Cooling the Air

Finding a solution for the 107 (and higher) degree heat was the big problem.  On the route down I'd tried to improve upon our rental car's poor A/C by buying a few bags of ice and putting some inside zip lock bags distributed in the passenger compartment and some in disposable aluminum pans on the floor board.  That did nothing to cool the interior.  I knew that the complete lack of space in the cab made it impossible to improve upon this crude method by simply adding more ice.  Instead I decided to do the only thing I could think of, create a rudimentary air conditioning system that was powered by ice, with the ice located outside the cab.  And that's what I built.

The key components of an air-conditioner related to the design I was going to employ were a refrigerated liquid, some cold coils that would transfer the cab's heat into the refrigerated liquid, an electric fan to accelerate that heat transfer, a pump to facilitate the circulation of the refrigerated liquid, an insulated container to hold said liquid, and hoses to carry the liquid to and fro.  I went to the local Pep Boys auto supply store and bought a third-party automatic transmission oil cooler to use as my cold coils, an electronic radiator fan to use as my fan, and fuel line to use as my hose.  At the local Walmart I found the bilge pump and large insulated cooler I needed.  And a quick trip to Radio Shack got me the switches and wires I'd use to allow me to turn everything on and off at will.

Retreating into the hotel room and out of the heat's insanity I assembled all the parts.  At this point I really wasn't sure how efficient the system would be, just how well it could remove heat from the cab, assuming a sufficient quantity of ice.  Once I'd installed everything in the vehicle and got a chance to test the system I was very pleased to discover that the system was very efficient at removing heat (that is, blowing cold air).  Even so, I wasn't sure if it would be cold enough, the hottest part of the day had already passed.  Remembering something from my high school earth science class I went back to Walmart to buy four big boxes of rock salt, which I knew would dramatically lower the freezing point of water and thereby drop temperature of the ice/water even further.  I brought along a big bag of tools for this trip and in it my infrared thermometer (it's a useful tool for motorcycle carburetor tuning).  I found that adding the rock salt dropped the temperature of the ice/water slush from about 32 degrees to about 3 degrees, which significantly improved the cooling in the cab.

Everything was very nearly a marvelous success, though it didn't take long for several mostly fatal flaws to emerge.  Thus, I'm not sure I can recommend this system to others facing similar circumstances.

This system runs through ice very, very quickly.  The air conditioning effect of my system would only last for about 45 to 60 minutes, after which the four to five bags of ice would be reduced to warm cabin temperature brine.  And as it doesn't make sense to break a 13 hour trip into 45 minute ice refilling segments we only had cool air for the first hour of every three or so.   Not to mention that the rate of ice consumption meant the system cost $5-8 an hour to operate, which is just pricey enough to make you think twice.  Worse luck, the fundamental resource without which the entire system wouldn't work (ice!) was magically unavailable at all the highway stops in West Virginia; WV was recovering from a serious storm that knocked out power to tens of thousands of residents who had bought up all the ice to save their refrigerated groceries.  And the final problem was that an automatic transmission oil cooler was not designed to be used as a cold coil for an air conditioner.  The honeycomb lattice of aluminum that does the heat transfer, through which air passes and becomes cold, seemed exactly the wrong size to rid itself of condensation that would form.  Cooling hot oil would create no condensation, but cooling hot air does.  My cooling system was so efficient that within mere seconds all the honeycomb elements of the oil cooler would be plugged up with water causing making the fan to send much of its uncooled air spilling out wherever it could escape the blocked holes.  To keep things working I had to keep running my hand across the face of the cooler to break the surface tension of the water so that it could all run off and allow the fan to work again.  This had to be done every minute or so.  I tried using some fabric to wick away the water from the honeycomb and re-evaporate it, but that didn't work.  And I planned to try introducing a light solution of soap to  the radiator surface to see if that might be enough to let it shed its own water, but I never quite got around to it before we got home.

Journey's End

I think the truck survived the trip better than the humans (and the dog).

On the first day of our return journey we only made it an hour before the ice ran out and the oppressive heat was just too much.  We paused for a few hours in the shade of a tree off the interstate.  Once the afternoon had set in and the ice was refilled we made it only another hour or so before a violent storm came upon us and we took shelter in the lobby of a hotel.  And when the storm lingered we called it a day.  At that rate I began to fear it would be 3-5 days before we'd make it home.

The next day became an unexpectedly long one, and we ended up completing the remaining 640 miles without stopping to sleep.  It was not our choice, however. We had planned to stop four hours away from home, but not only was West Virginia out of ice (because of the aforementioned storm), every hotel was full up. We called more than twenty, all the ones that took dogs and a few that didn't.  In the end we were left with no option but to drive until we reached home.

While I can't claim to be an expert at driving five ton trucks, but the fact that I didn't hit anything, and had no problems surely says something.  I was actually amazed at how well it drove, aside from the miserable uphill speed.  I wasn't able to do more than 30 mph on many of the hills coming back.  Going only 30 mph when other vehicles are doing 75 mph is certainly not an ideal situation, but the advantage of driving through the night was that the bulk of the hills we encountered were climbed when few others were on the road.  The top speed of the vehicle on level ground is only about 57 or so, which meant that in the entire 720 mile trip I don't think I passed a single vehicle.

In the end the toll on man and dog was high.  The stress from the drive left us humans bickering through out the next couple of days, and Osita ended up with a vet trip to treat vomiting and mild dehydration.

But all of us restored, my focus will now be on turning the M820 into a mobile gentleman's study (and my office).

^ Quinxy

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