Hot-Rod Derby on the Salt Flats (Aug, 1950)
Hot-Rod Derby on the Salt Flats
By Ewart Thomas
ON THE Bonneville Salt Flats in Utah late this month you’ll be able to see the oddest collection of fast automobiles ever assembled.
Some will be “competition coupes” with cabs which appear to be squashed flat, one or two may be “twin tank” jobs that resemble a wartime P-38 with the driver in one compartment and the engine in the other. Some will be flat streamliners not much more than knee high.
Each represents its builder’s ideas on how to design the world’s fastest car, in its class, with the funds available.
One of the cars is nicknamed the Ant-eater because it has a snout projecting in front. The driver sits over the front axle in the long snout because the conventional body is entirely filled with engine and supercharger. Another is a twin-engine “odd rod” with the driver in the middle and an engine over each axle.
Some of the cars sport Model-T bodies and appear to have been built 30 years ago but even these cars, beneath their hoods, have snarling, hopped-up engines.
All of the cars are classed as hot rods because they are home-built creations, but the hot rods have grown up. Amateur automobile testing has become a recognized sport and most of the rods are pure racing machines of advanced mechanical design.
The occasion for the meet is the second annual running of the Bonneville National Speed Trials and the dates are August 21 to 27. The place is the table-flat expanse of hard salt on which John Cobb set his automotive world record for the flying mile at 403 miles per hour.
Cobb’s record won’t be threatened, of course, for he had 2400 horsepower under the hood, and few of the home-built cars can develop more than 225 or 250 horsepower. The present hot-rod record of 193 miles per hour (or 189.78 miles per hour average for two runs in opposite directions) was set at the salt flats last summer by a streamliner with a Mercury engine which had been souped up to produce 225 horsepower.
Alex Xydias and Dean Batchelor of Burbank, Calif., who own the car, hadn’t expected that their Special would go that fast, and they first used tires that were guaranteed for speeds of no more than 175 miles per hour. Both front tires lost their treads at about 190 miles per hour and the bodywork was slightly damaged. The car was brought to a safe stop and later, using Indianapolis-type tires, set its present record. Two professional race cars that were clocked at the same meet last year made top speeds of only 136 and 144 miles per hour.
This year Xydias and several other owners of streamliners are hoping to do 200 miles per hour or better. A typical car that is being put together especially for Bonneville is a rear-engine streamliner from Pasadena, owned by Marvin Lee, that was clocked at 151 miles per hour, both ways, on the salt last year. This summer a new body was designed for it, and the Chevrolet-six engine that last year developed 243 horsepower at 4400 revolutions per minute has been additionally reworked to turn up 5000 revolutions per minute. Straight alcohol is used as fuel, metered through a high-pressure injection system.
Lee’s new and narrower body was designed with the help of an aerodynamicist friend who took special pains to obtain a minimum frontal area. To avoid building wheel Housings that might be larger than necessary, for instance, wheels and tires were whirled in a special test rig at 2800 revolutions per minute, roughly equal to 230 miles per hour, to learn the amount of centrifugal growth that occurs at that speed. Measurements showed that the tires expand 1-7/16 inches in diameter at that speed and the dimensions of the wheel covers were accordingly laid out to allow for that growth.
Hot rods fall into two broad groupsâ€”the street jobs or highway cars that are used for ordinary transportation as well as time trials, and the special racers that are used only for time trials and that are towed or trucked to the scene. Cars in the latter group usually have no starting mechanisms and must be pushed. In these cars the nose is completely cowled to reduce wind resistance. An oversize water tank replaces the radiator and no cooling fan is used. The engines don’t overheat because the cars are driven no more than five miles at a time.
The street jobs, too, usually dispense with the fan to reduce horsepower wastage and many of them use two radiators, one behind the other, to insure proper engine cooling in traffic. Many of the cars have quick-change rear ends or gearboxes so that a gear combination can be installed to fit a tire size that is being tested or for driving against a heavy wind.
Engines are completely reworked and the changes may include special ignition, special intake manifold with up to one carburetor per cylinder or a fuel-injection system, high-compression heads, enlarged cylinders to take oversize pistons, “stroked” crankshafts to permit the use of longer connecting rods, and superchargers. In southern California, center of the hot-rod sport, a number of speed shops cater to hot-rod owners, providing them with special equipment that adds to an engine’s power.
Special fuels and carburetion often add many miles to a car’s top speed; even the mixing of about 10 percent of water to the gasoline has been found a help. The trick here is to pour the water and gas into cans, shake the fuel vigorously, dump it into the tank and take off at once, before the two liquids have a chance to separate. More two sizes smaller to pull against the wind on the return. Every little bit helps, the drivers figure, and in some cases heavy cardboard and yards of masking tape are used to fill hollows in a body, to smooth its contours and increase its streamlining.
Classes of cars that will run at Bonneville are: roadsters equipped with stock bodies, radiators and shells, and with clutch and full transmission; modified roadsters; lakesters that may have specially built bodies not exceeding 36 inches maximum width; competition coupes, and streamliners with special bodies of any dimensions.
These classes are subdivided according to engine displacement into five engine groups ranging from less than 91 cubic inches to 350 cubic inches and over. Engines must be of American manufacture and of the internal-combustion reciprocating type.
All drivers must wear approved safety belts and goggles and cars must be equipped with fire extinguishers. No windshields of glass are permitted but glass head lamps need not be removed if they are suitably taped. Cars that are not designed to start under their own power must be equipped with a rear push-plate or bumper for push starting. There are various other equipment and safety rules and all cars that compete at Bonneville are subject to inspection.
The Bonneville time trials will be conducted by the Southern California Timing Association in cooperation with the Salt Lake City Chamber of Commerce. The trials are open to all fast cars that can meet the required safety rules. There is no limit to the number of changes that a participant may make to his car or engine nor is there a limit to the number of times that he may run the course. As soon as he finishes one run he may drive back to the starting end and get in line once more. Each run will be timed.
The course is a straightaway and is five miles long to allow plenty of room for accelerating to top speed and for slowing down again. Photoelectric timing devices that are accurate to one thousandth of a second will clock the cars over a 1/4-mile distance and a one-mile distance laid out along the middle of the course. The 1/4-mile trap will be used for timing all cars until the latter part of the afternoon of each day, after which the day’s fastest car in each class will have a chance to make a run both ways over the one-mile distance for an official record.
It’s hard to say how many cars will be tested this year but a guess is that some 200 cars from all parts of the United States will participate. Spectators may approach within 1/8 mile of the course during the trials. Bonneville is six miles from the small town of Wendover on the Nevada border where meals and some hotel accommodations are available. Many of the spectators and participants will camp out on the salt during the week.