PLAYING the World’s Most Dangerous Game (Sep, 1931)
PLAYING the World’s Most Dangerous Game
by ROBERT M. ROOF
(Builder of cars for dirt track racing) It is danger in sport that fascinates both spectator and participant, which is the main reason why dirt track racing is gaining in popularity every year. In this article a man who has devoted his life to the development of this thrilling sport gives you some real inside information on the men and cars that burn up the ovals at the state and county fairs about this time of the year.
BOB CAREY, a lead foot king of the dirt tracks, put his leaden foot down on the accelerator in a race at Winchester, Ind., last Labor Day and took a little souped-up Chevrolet around a half mile track in 23 2/5 seconds.
On the wall of my shop, where the power parts for that car were built, hangs a faded photograph taken at that same Winchester track in 1922. Thirteen cars—unlucky number—are lined up for the start of a race run just eight years ago. Five of the thirteen drivers are dead today, killed on dirt tracks. Among them is Chance Kinsley, who that day in 1922 drove one of my double overhead cam shaft Fords to victory in every event on the program.
Five out of thirteen dead! The half mile dirt track race game has well earned its title of the world’s most dangerous sport.
Yet there are somewhere between 200 and 300 half, five-eighths and mile dirt tracks in the country staging automobile races, and more are being added every year, while orders for cars and parts are coming from all over the world.
From its initial stronghold—northern and central Indiana, western Ohio, eastern Illinois and southern Michigan—the lure of the dirt track racer is spreading wherever fast automobiles are loved.
The Frank Lockharts and the Billy Arnolds of the brick and board speedways came up from the dirt tracks. The boy that can drive a souped-up Ford or Chevrolet to victory on the half mile ovals can drive anywhere.
Yet dirt track racing is a thing apart, totally unlike racing on the Indianapolis speedway, or the big bowl at Altooria. Cars that can stand the grueling grind of 500 miles on the two and a half mile brick track at Indianapolis can’t begin to compete with some backyard garage built Ford or Chevy even on a mile dirt track at speeds of under 90 miles an hour. Sounds funny, doesn’t it? Yet only last year two of Fred Duesenberg’s fine big speedway racers were taken over to the mile state fair grounds track at Indian- apolis and on their time trials couldn’t get better position than second row, while our little rebuilt pleasure cars were in the front line.
The answer is the trick of racing on the small ovals. The driver who eases up on his gas pedal at the turn is out, and may be dead. The speed kings of the dirt ovals throw their cars around the banked turns in a skid and then give the motor more gas and depend on the power in the rear wheels to pull them out. Front wheel drive is no good on the small tracks—too light in the rear end. Four wheel brakes also are out, and a lot of the boys don’t use any brakes, for usually if you get in trouble there isn’t time nor place to use them. It’s easier to pull in your head, trust to luck, and let her roll. We’ve had cars somersault two or three times without damaging the driver.
Some 200 boys are racing on the dirt. Most of them break in at around 20 to 25. Older men, whose reflexes and reactions have begun to slow down, make poor beginners. Specially good drivers who get in early enough may last 15 or 20 years. Ira Hall is around 40 years old and has been in the game for 15 years. Dutch Bowman was about the same age and had about as many years of racing behind him when he was killed at Kankakee, 111., last fall. Most of the new boys are garage mechanics who hang around and make themselves useful until someone offers to risk a $3,000 car on their ability to drive it. It’s the lure of the speed and danger that brings most of them in, and keeps them racing for years. Financially, the rewards are far from in keeping with the risks. Three or four thousand dollars a year is a good income. But a lot of the boys would drive for nothing if they couldn’t get a mount on any other terms.
The risks are not only big and the pay small, but the work is hard. The average life of a motor between overhauls is 40 miles. Imagine tearing down an engine and rebuilding it every week, in order to compete in two or three 5-mile and one 20-mile race Sunday!
The speeds have been getting so high and the life of the engine between overhauls so correspondingly short that we may have to give up the rebuilt pleasure car engines altogether and use special racing jobs. In fact I’ve just turned out a marine type, four cylinder engine, that develops 175 horse power at 5,000 r.p.m., as compared to around 90 h.p. from a souped-up Chevy or Ford at around 5500 r.p.m. With the more powerful racing engine we will be able to turn them over at around 4000 r.p.m., prolonging their life considerably, and still have plenty of power. And the marine type, dry sump job, makes frequent overhauls almost a pleasure. Inspection plates on either side of the crankcase give quick access to the connecting rods and shaft, and—a real novelty—I’ve cast individual cylinders in square units, which are drawn together by bolts, with gaskets between the pairs, to form a block with a continuous water jacket. Yet I can take it down and have all four individual cylinders on the bench within an hour. The separate cylinder idea eliminates complicated coring in casting the cylinders and jackets, makes it easy to clean out the casting “fins” with a file, and if one cylinder goes bad it can be replaced, instead of buying a whole block. The economies in manufacture are so great that we will be able to sell the complete motor for about the price of a second hand Ford or Chevy engine plus the conversion parts needed to turn it into a race car motor.
The thing that makes dirt track racing so dangerous, that wears out engines so fast, and makes it impossible for the big race cars to compete in the game, is the constant acceleration and deceleration on the short stretches and turns. For the same reason supercharged engines can not be used, as a supercharged job will not build up power fast enough on the short stretches.
While the big speedway cars are using a compression ratio of not more than 8V2 to 1 we are using up to 11 to 1 on the dirt tracks. The things that have been done with special power heads and other parts applied to the old Ford and Chevy fours are amazing. Bureau of Standards tests of the Ford Model T showed around 13 to 14 h.p. We get 90 h.p. out of the same engine. In the old days race drivers thought they had to have high gear ratios to get high speed. Now we know we need just the opposite. You couldn’t get the horse power out of an engine with high gears. Nowadays we get a high motor speed and then transmit the power with a lower ratio. It’s largely that high motor speed that enabled us to get 90 h. p. out of the old Model T motor—and the high speed, of course, required overhead camshafts and valves, power heads, special steel in the timing gears and other parts, full skirted nickel-aluminum alloy pistons, and special fly wheels which wouldn’t burst at speeds of 5000 r.p.m, or better. In souping-up the Chevy engine we used to take a 72-pound block of specially forged steel and machine out of it a fly wheel weighing 12^4 pounds. Now we use Lynite and get the same results from a 7-1/2 pound fly wheel.
Split skirt pistons are never used for racing. Fuel mixtures are very important, and vary with every compression ratio used. The fuel is usually ethyl gasoline and benzo1l in the proportions—for an 8-1/2 to 1 compression ratio, of two gallons of benzoil to five of ethyl gas. If we can get pure ethyl to add to gasoline, and so increase the ethyl percentage, we can eliminate the benzoil, but the mixture has to be carefully prepared, for too much ethyl is just as bad as not enough. , Lots of people have the idea, a hold over from a dozen years or so ago, that dirt track racing is a hippodrome game, with a lot of cars owned by one promoter and every race fixed to let a certain driver win. Nothing is farther from the truth. The promoters quit the game because the public lost interest in fixed races. Nowadays every driver is on his own, either trying to win for himself or the owner of the car, but it is rare to have more than one car owned by a single individual in any race. The dirt track game differs from the big speedways, however, in one important point. The track owners usually give a guarantee to get the car owner to bring his machine to the track, the guarantee being in addition to the purses, and protecting the owner against a complete loss in event mechanical trouble keeps him from placing in any race. The guarantee may range from $100 for an especially speedy car with a noted driver, down to $10 for a “jallopy.’ Jallopies, in the argot of the dirt tracks, are poorly built cars. Not exactly junk, for any car that can get around the dirt ovals at 50 m.p.h, or better is far from being a piece of junk, but just a car that hasn’t a reputation for winning.
The dirt drivers talk a language of their own. A “lead footed” driver “unwinds her” and takes the turns “floored,” meaning a pilot with a reputation for bearing down with his gas foot drives the car “all out” and takes his turns with the accelerator pedal down to the floor boards. Any car is a “piece of iron” unless it belongs to the “jallopy” class; connecting rods are the “galloping irons.” The opposite of a lead footed driver is one with a “balloon foot.” “Selling out” means to jump when a crash is about to happen. And last summer a driver asked me if I couldn’t put zippers on the crank case so he could get in for a quick overhaul!
I’ve been in the dirt track game as driver and builder of racing cars for fourteen years, having driven my first race at Winchester, Ind., in 1917. I had patented the first overhead valve gear for a Ford and that same year, on the old Sharonville track at Cincinnati, cars equipped with my overhead valves won the first four places in a field of 25 cars.
We’ve learned a lot about high speed engines since those days. For example, who would expect that the length of the connecting rod has an important bearing on speed? Yet it is a fact that the shorter the rods, and the closer the piston to the crankshaft, the faster you can run the engine. The reason lies in the inertia of the rod, and the long rod is apt to whip itself to pieces before a race is half run. Another trick we have learned in rebuilding pleasure cars into racers is to move the engine back about ten inches, at the same time we are shortening the wheel base from around 108 to 90 inches. Moving the motor gives a better distribution of weight and helps take the turns in high speed skids.
For a time narrow tread was tried, with the idea that the closer the wheels were together the easier they would take the turns. But that was dropped, and now we stick to standard tread as it proved best. We do do one thing to the front axle, and that is to straighten out the camber in the right wheel (all dirt races being run counter-clockwise around the track). Straightening up the outside wheel and leaving the inner one leaning, or with camber, helps considerably on the turns.
It probably will surprise many people to know that we only use 1/32 inch of babbitt metal in the connecting rod bearings, and that we no longer groove the bearing to distribute the oil. Instead of the bearing groove we turn a groove into the shaft, as we have found that gives better distribution of oil— which, of course, is supplied by force feed through the hollow shaft. The 1/32 inch of babbitt in the bearing is not just melted and poured in. Instead it is “thrown in” by centrifugal force from a feed member turning at around 5,000 r.p.m., and then ground down. By throwing the metal in we get better and more even distribution, and freedom from blow holes and other imperfections.
High compression and high turbulence are absolutely essential in a racing car. Various types of heads have been designed to increase these features in stock Ford and Chevie motors. One device known as the Hi-Turb head for Fords not only increases the compression but produces a churning or whirling motion in the combustion chamber which assures a perfect mixture of fuel and air.
The Chevrolet racers have been popular with the boys because you can get so many standard gear changes for them. Including Pontiac and other gears which can be used in the Chevrolet there are about seven gear sets which can be obtained for a few dollars each, whereas special gears would cost around $40 a set. With a full range of the standard gears a car is fixed for most any type of track or rules.
With cars of this type the dirt track boys are competing at times against some of the finest straight eights specially built for the speedways. The mile dirt track record of a living driver by the way, is held by one of Harry Miller’s creations, piloted by Louis Snyder, who did a mile on the fair grounds track at Springfield, 111., in 40.9 seconds. That was 1.98 seconds, however, slower than the all-time mile dirt track mark set by the late Frank Lockhart. Robert Carey, in one of our Chevies, did a mile in 43.9. The record for a % mile track is held by Mauri Rose, at 24 9/10 seconds, which compares well with Carey’s 23 2/5 for the half mile at Winchester last fall.