Friday, July 06, 2018

The Mobil Economy Run, told by Chad Johnson, the only remaining person to tell the tale... and the inspector of the competing cars from 1952-67, and member of the tech staff.

My name is Chad Johnson, and was the owner of "Chad Johnson Auto Repair", Burbank, California. (From 1946-1986). My age is 97, and I live in a retirement community in Palm Desert, California.

I joined the run in 1952 as an inspector, and reported to Mr. A. C. Pillsbury, AAA, and Mr. Frank Meunier, Mobil Oil Company. I was involved in every event from 1952, including the last run to Boston, in 1967. After a few years, I became a member of the technical staff, and spent much time each summer with both of these gentlemen, plus other members of the technical staff to make changes in the operation of the event. Our main objective was to make the event as fair as possible, and I think we succeeded.

The run it’s self is only the culmination of many months of hard work by many people. I would like to give you my observation of the workings before the start of the run.

Prior to my participation in 1952, it was my understanding that the entry cars were brought in to an impound area by the contestant, and from there on, the car was under the control of the AAA and staff. I was also told that every engine had the cylinder head removed, and checked for cubic inch displacement, (bore and stroke), and compression ratio. That is about all that I remember from the early days.

On my first day at the impound in Pasadena, (It was a large Quonset hut on the Rose Bowl grounds, used for the building of the Rose Parade floats). It was a rather large compound, fenced and gated. The building could accept 30-40 cars, and a large parking lot. Mobil had set up the wheel alignment equipment, a dynamometer, and fuel test site. (Read article further on). The property was guarded 24/7 when used by Mobil for the run.

I reported to a Mister B. Reeves Dutton, famous old time race driver, and riding mechanic in the very early Indy 500 days. He was in charge of the impound, where all of the cars were stored and inspected before they were allowed to go out on break-in runs. There were no more cylinder heads removed, and the run officials selected the cars from random.

But first, lets start at the beginning. There were different categories, or classes of cars, e.g., four cylinder, six cylinder, eight cylinder, and so forth. The entries can be from Auto manufactures, Auto dealers, or private parties. All entries had to follow all procedures. I have read in some of the publications regarding the run that the cars were purchased by either the AAA, or Mobil Oil Co. to my knowledge that was never true. Those of us, who were to select a car for the run, always had a document from the manufacture or the dealer. There was seldom a problem when we called at dealers to select a car. Over the years, there were very few private entries, and I was not involved with them. We were given specifics as to the engine size, type of transmission, gear ratio, and everything as advertised for the run car. The run car was to be exactly the same as one would purchase from the dealer. As the run progressed from year to year, our method of selection also changed. We suspected that cars from not only one, but also several manufactures were building a few special cars for the run, and planted them where we might select one. We started to select cars from a greater distance than in the past. We were allowed to go anywhere to select our choice of car

I remember one year the plan was to go to Detroit to each of the assembly plants of the entered cars. We had teams of two, and at 8 A.M., we all appeared at the different factories, and presented our papers to management, to select a car. This is what we want: select an engine, transmission and differential, put a seal on each unit, and had them build us a car. When finished, we drove it off the assembly line, put it on a haul away truck, and stayed with the vehicle until we reaches Pasadena.

Studebaker was always a suspect and was probably easier to plant a car, so one year we picked a station wagon, which was not allowed, and also a car that was allowed. The factory allowed us to switch engines, so we knew that we had an honest car. Ford always had black painted cars for the run. We always suspected planted black cars, so one year, we chose a green, and a beige color cars. When the engineers from Ford saw the wrong color it hit the fan. All of the advertising of our cars, they are always black. So we painted both black.

So much for the selection of the run cars. What happens now in the impound area, not much, if anything, has been written about the procedures.

In my earlier years on the run, when a car comes in for the first time, the car is checked over to make sure it conforms to visual specifications. Then open the hood, and then the work began. In order to confirm that nothing had been or will be tampered with, many different pieces were drilled, (Such as on aircraft engines), and sealing wire and a led seal was used. This would include the air cleaner, radiator cap, one nut on the carburetor-mounting flange, the distributor, oil filler cap, dip stick, gas cap, hood, and on and on. One of my jobs was to watch any operation under the hood, and then safety wire and seal whatever component had been serviced. When everything was finished, I would seal the hood. By now, I am now part of the technical staff, and voiced my opinion as to all of this work drilling and sealing a vehicle when it never leaves our sight. One would think that securing the hood would be sufficient. That was the last year for that procedure. The next year our crew was given new numbered sealing devices, and the only things sealed were the hood, deck and access to refueling. Another of my jobs was to align the front end of every car on the run, plus balance all wheels. We also had a dynamometer that was used by the contestants as needed.

All work under the hood of every competing car was done by a representative of that particular vehicle, while being observed by one, and sometimes by more, of our crew.

This time was before computers, fuel injection, and pollution devices.

Every carburetor was removed, and all jets were to specification, or had to be changed. Fuel level also to specification. The carburetor was also checked with the engine running with proper specs for the vacuum advance on the distributor. The air cleaner had to be stock, with no alterations, and the insert was purchased from a local parts store to assure that the element had not been altered. The same thing with oil filters, they were from a local parts store for the same reason. Each distributor was removed and put on a Sun distributor machine and checked for proper vacuum advance operation. Also the mechanical advance had to be to specs at various RPMs. The timing was set to factory specs.

The thermostats for engine temperature control were removed and checked for accuracy. If they were not to those of a particular cars specification, they were replaced.

The gear ratio was verified, also to the tire size and air pressure.

After every thing was checked and verified as stock in each run car by our crews, and also a member of each entry, the hood was closed and sealed. There was no reason for the hood to be opened after that, except to check the fuel or water level after a break-in run. Each car was sealed, locked and in a secure environment in our impound. Whenever a run car left the impound, it was by appointment, and always with an observer, an engineering student from Cal. Tech. If it were to be a long trip, two would be assigned, so as not to ever leave the car alone.

I read in one publication that contestants were allowed to tweak certain things on the carburetor and timing. That was not the case in the years what I was involved with the run. Also there is the story about taking a test car, pulling a device behind it, to create a dust storm, in order for the run car, without the air cleaner, to ingest the dirt. If that happened, it must have been before 1952. Another story told about the tires, and how they were abused and worn down intentionally. Yes, that did happen to a few cars, and I believe that we were directed to the factory that made the tires, and we were probably directed to “planted” tires, so after that, every run car had to make the run on the tires that the car came with. I have read in different publications that Mobil purchased the run cars, and I believe that to be false.


And finally, probably the most important procedure at the impound area, was the method of calculating the fuel used on each car in the run. At this time the standard fuel tank that came with the car was used. So how is the exact volume determined? And how does one calculate to the hundredth of a gallon fuel consumed? Each car had a different size, and position of the pipe that filled the tank. Some short, some long, some straight, and some in different curved configurations. So if you can follow the procedure, picture in your mind the following:

Each car was placed on two level cement pads, constructed special for this operation. They were several inches above ground, in order for a worker to use a creeper and get under the car. One for the right side wheels, one for the left side. Each was longer than the car to be tested. Once the car was on the pads, a permanent mark (----) was placed on each fender, behind the wheel. All cars had the same mark at the same height. An iron stand, with a stable base, with an extension at the top, a with hairline marker, taller than the mark on the fender. A marker was placed at each corned of the car by the fender marks. There were four hydraulic bumper jacks, (Thanks for real bumpers in those days), and the car was raised to the height of the marks that had been placed on the fenders with the iron stands at each wheel. The stands were on the pads along with the car, and had a hairline point to match the mark on the fender. We now have a repeatable situation any where we go, provided there will be duplicate level cement pads at every night’s run, this needed to be able to give each day’s results. The logistics are wild. The run must end each day near a Mobil station, with room for the newly installed cement pads, to calculate the day’s results. This is repeated at the end of every day’s run. This method of calculating fuel used was very costly and not always accurate, by later standards. And by installing the cement pads, it gave away the secrecy of the route to be traveled. Many negatives. There must be a better way.

But there is more. Back to the impound and the car is jacked up on the pads. In those days, all tanks had a drain plug, and we drained each tank until there were only three drops in a 30 second period. There was also a custom made removable custom metal marker that went into the neck of the fill pipe of each car. Each car had it’s own personalized gauge, with a mark to establish a top-off line. This process was done three times on each car to assure the accuracy of the line, as a top-off mark.

At each refueling station used at the end of a days run, the cars were put on the cement pads, leveled, and ready for fuel. The fuel nozzle had been removed, and a special recording device, using a roots counter, measuring in the hundredths of a gallon had been installed. Then the nozzle was replaced, (Not a automatic nozzle). The temperature of the fuel was also recorded at this point. If refueling was needed enroute to the day’s destination, the cars were not leveled, but the fuel was delivered through the same recording devise in even gallons. The answer would be to install custom fuel tanks in the trunk of each competing car.

Fuel Tanks

To my knowledge, there are no pictures of the special tanks used in the MER. There is a saying, “A picture is worth a thousand words”. And I might use them all in trying to describe the tank, so I will include my requirements necessary for a tank…

(The following are estimates as to the measurements, numbers, and volume of the tanks). The Internet provided no information as to these tanks that I could find, only the fact that they were used. All of this is from a 97 year old man, and the memory and mental picture from 65+ years. .

Mobil’s answer was a custom fuel tank for each run car. There were about four, or maybe five different configurations of tanks necessary to equip the field of run cars. The tanks were either square, or oblong, to fit the need. The capacity would be 16-18 gallons. The top was not flat, but tapered up at about a 15-degree angle from each corner, to join a 4-inch pipe, 5 inches long. Inside this pipe, was a bracket that contained a ¼ inch x 3 inch threaded adjustable screw, with lock nut, with a ¾ inch disc attached at the bottom of the screw. After this tank was calibrated, the adjustment screw was locked and sealed. On top of this 4-inch pipe, is a 10-inch diameter x 4-inch high expansion chamber, with a swing top. There was an “O” ring installed in the top flange of the expansion chamber to seal the tank. The top cover was a larger diameter than the expansion chamber to accommodate the hold down bolts. There were 3 3/8th inch threaded bolts attached (120 degrees) to the outside of the expansion chamber, and about 1/2in higher. One permanently attached, and the other 2 were on a pivot. To add fuel, loosen the 3 knobs, swing out the 2 pivoted pieces, and turn the lid on the pivot point. To close, reverse the procedure. Also at the top of the tank, there was an 1&1/4 inch angle on the outside of each side. These were drilled in several places to accept the hold down turn buckles. Each tank had a permanently mounted bubble level, and also a Weston thermometer, with 7-1/2 sensor installed. (The fuel Temperature was recorded at both the tank and the fuel nozzle to calculate the actual MPG.

Changes made over the years.

The Mobil Economy Run mileage was first based on “Ton Miles” per gallon, not actual mpg. This created a huge statistical problem for everyone, and was not a fair representation for the contestants. The MER had a driver, co-driver, and a observer in each car. The car was weighed and each passenger was weighted individually, and a total weight was established. To balance the field of the contestants, lead bars were added to the cars to establish the method in which to calculate the ton mpg. At every brunch stop, the observers were switched from car to car, to eliminate any chance of collusion. This meant that a special crew was needed to carry the extra weight in lead bars, and switch the weight in every car at the brunch stop. This also happened at every overnight stop. This procedure was necessary to obtain the proper calculation of the “ton MPG”.

This was the second change, we as the technical staff, recommended to change, and eliminate this procedure. (Our first recommendation was to change the way the run cars were selected).

Our technical staff saw this event in a different view than how it was operated in the past. The most important part of the run was the correct mpg. The method that was in use was fair, but not always correct. ( See section on refueling).

Another thing that bothered us were the unrealistic average miles per hour the run cars traveled. This was supposed to replicate what gas mileage a family on vacation should expect from their exact car and traveling at a reasonable highway speed, instead of the low average of 30s miles per hour.

And why should this automotive event be for men only? Women are certainly capable of driving a car, and should be able to learn how to get the best mileage from a car, and on vacations, women probably did a lot of the driving. Again, a more realistic situation.

Probably the most important of our changes, was the method of correctly calculating the true mpg of each car. Our present method of installing the level cement pads at the refueling station at each night’s stop, leveling the cars with four hydraulic jacks, using hand made fuel gauges to insert in each tank, was labor intensive, and was also very costly, and to be repeated year after year. Mobil

top perimeter of the top, was an angle 1-1/4 inches on all sides. This had several 3-1/8 holes drilled for the hooks to secure the tanks. There also were three threaded devices to allow the tanks to be leveled. Each tank had a bubble level permanently mounted, and a Weston thermometer with a 7-1/2 inch pickup installed. (The fuel temperature was recorded at both the tank and the fuel nozzle.) as part if the calculation.


The tank would be trunk mounted, secured to the floor of the trunk, at three points, by 3/8” eye bolts through the floor, with 2” washers, top and bottom, and lock nuts on each side of the floor. There was also a 3/8” hole drilled through the floor for the new fuel line, from the new tank to the existing fuel line that was disconnected from the stock tank. An inline fuel filter will also be installed at this time. The tank will be secured by 3 turnbuckles with lock nuts, with hooks at each end. One for the eye bolts in the floor, and one for a hole in the angle on the top of the tank. When the tank is to be fueled, the 3 turnbuckles will be loosened and remover from the tank. The 3 leveling screws will be adjusted to level the tank. Open top, add fuel to the small disk in the pipe. Secure top of tank, raise leveling legs, replace turnbuckles in tank and eyebolts and lock in place.

Chad Johnson

Wednesday, July 04, 2018

(ain't that incredible that Chad is 

1 comment:

  1. Man, this is information I haven't seen anywhere is all my years of reading car mags and engineering publications. Fantastic stuff, thank you.