The failed Indy “nitro ban” 

Nowadays, the use of nitromethane to boost the horsepower output of racing engines is well known, but such was not the case in the nineteen fifties.  Produced by the treatment of sodium chloroacetate with sodium nitrite to create the chemical compound CH3NO2, an colorless oily liquid that is very effective as a power adder because carries its own oxygen.  Nitromethane is 52-1/2 percent oxygen by weight, so it needs much less atmospheric oxygen to burn and release its massive energy.

The theoretical stoichiometric air/fuel ratio of nitromethane ne is 1.7:1, which means it takes 1.7 pounds of air are needed to burn 1 pound of nitromethane. By comparison the stoichiometric air/fuel ratio of gasoline is 14.7:1 and methanol commonly used in Indianapolis racing engines has a stoichiometric air/fuel ratio of 6.45:1.

As far back as 1919 Arthur A Backhaus of Baltimore Maryland patented a fuel mixture of gasoline, alcohol and nitro benzol, but Backhaus did not make any claims of increased power output. In the nineteen thirties, Carleton Ellis, Standard Oil’s pioneering automotive chemist, patented several mixtures of nitro-hydrocarbons as ‘anti-knock” additives for lower octane gasoline.

Prior to the outbreak of World War 2, the Mercedes and Auto-Union racing teams both used nitro compounds to boost horsepower; the German teams used a mixture of 85-percent methanol, 10-pecent nitromethane and five-percent acetone. While the mixture increased horsepower, nitromethane was also corrosive to the internal components in the engines and fuel system which required a strict program of draining a flushing the fuel system between races.  

In 1949, Southern California hot rodder Vic Edelbrock was introduced to nitromethane by midget racer Eddie Haddad, who had been given a gallon of nitromethane by the trio of pioneering tether car builders the Dooling brothers. Edelbrock experimented with the use of nitromethane in his Ford flathead V-8 60 engine to keep up with the purpose-built Offenhauser four-cylinder racing engine which had a significant power advantage over the Ford V-8 60 cubic inch power plant.

Through trial and error Vic learned that the use of nitromethane required the metal portions of the fuel system to be nickel-plated and the use of spark plugs with a cooler spark tip.  Edelbrock's late-night work paid off as on the evening of August 10, 1950, Vic’s midget the seventh Kurtis-Kraft car built driven by Rodger Ward to victory at the famous Gilmore Stadium with a 20% blend of nitromethane in the tank, then Edelbrock and Ward followed up the next night with another URA midget race win at Orange Show Stadium in San Bernardino.   

The growth of the use of nitromethane in American open-wheel racing paralleled the wide-spread use of fuel injection as both spread east from the West Coast. Following his service in World War 2, Jim Travers partnered with Stuart Hilborn to develop and sell fuel-injection systems, but that venture failed.  Hilborn returned to working at night in his home garage to perfect his system while Travers fulfilled his promise to his war-time buddy Elinor “Swede” Lindskog to go midget racing full-time.

Lindskog from “backwoods Washington” was a pre-war midget racing standout, and with the “Swede” driving and Travers on the wrenches, the pair were very successful, but their partnership was tragically short-lived.  On the evening June 27, 1946, “Swede” set a new track record of 14.78 seconds on his first timed lap on Gilmore’s quarter-mile track, but on his second lap, Lindskog’s midget crashed into the outside retaining wall and rolled over three times. Just 29 years old, “Swede” died enroute to the Hollywood hospital and Jim Travers swore to quit racing.    

Eddie Haddad soon persuaded Travers to join his team which was owned by Southern California garage owner John Balch. Shortly afterward, Balch sold the team to Superior Oil Company tycoon Howard Keck and before long Keck wanted to add a second mechanic to the team and Jim Travers suggested his dry lakes competitor, Frank Coon.

In 1948, with Keck’s backing, Travers and Coon ordered a new front wheel drive chassis from Los Angeles metalsmith Emil Diedt to try to conquer Indianapolis. During the 1948 Indianapolis ‘500’ driver Jimmy Jackson ran just outside the top five for most of the race, but a good finish was spoiled when a wheel spindle broke on the sleek maroon machine with seven laps to go and Jackson spun into the infield and was placed tenth.

Early in 1949 Stuart Hilborn left his day job to devote himself full time to the manufacture of his injectors, with the first production run for the 105-cubic inch Offenhauser midget engine with Eddie Haddad as one of the salesmen and pioneers of the use of the fuel injection system. Hilborn then advanced into building injectors for the 270-cubic inch Offenhauser engines for Indianapolis cars.  

The prototype Offenhauser 270 injector system was fitted to the Keck machine and Jimmy Jackson qualified with the first Hilborn fuel injectors at the Indianapolis Motor Speedway, but the team switched back to carburetors for the 500-mile race.

By 1950 there were seven Hilborn injection set ups at the Indianapolis Motor Speedway and some of the qualified teams rented their set-ups to other teams for qualifying. Car owner Howard Keck and his mechanics, “the Whiz Kids” Travers and Coon hired three-time Indianapolis 500 winner Mauri Rose who liked the Hilborn injection system. 

Rose averaged 132.319 mile per hour (MPH) to qualify on the outside of the front row as the highest qualifying injected machine, then Rose and five other cars raced in the 500-mile race with the revolutionary Hilborn injectors installed.

The use of nitromethane was first discussed publicly after the 1952 race - most railbirds figured that about half that teams used a mixture of 10-12% nitromethane for qualifying.  In 1952, on straight methanol the 270-cubic inch four-cylinder Offenhauser engine developed 345 horsepower but a dose of ‘pop’, as nitromethane became known, added at least 40 horsepower, and could add up to as much as 100 horsepower depending on the amount of nitromethane used. In addition to the cost - nitromethane cost $5.35 a gallon in 1952 ($50 a gallon today), too strong a dose of nitromethane could quickly destroy a racing engine.

A 1954 Society of Automotive Engineers (SAE) paper prepared by E.S. Starkman a University of California professor entitled “Nitromethane as a Piston Engine Fuel” found the when added to methanol, nitromethane increased power by 13 percent, but Starkman’s experiments found that nitromethane percentages above 20% created unfavorable pre-ignition conditions in the cylinders.     

Jim Travers, left and Frank Coon, right are congratulated by 

Indianapolis Motor Speedway President Wilbur Shaw 

at the 1953 "500' Victory banquet as the mechanics on the winning car.

Photo courtesy of the IUPUI University Library 

Center for Digital Studies Indianapolis Motor Speedway Collection  

  

It was widely believed that in addition to adding the liquid for time trials, several teams added a small percentage of nitromethane for the running 1952 Indianapolis 500-mile race. Those teams included oilman Jack Hinkle’s team with driver/mechanic Jack McGrath, J.C. Agajanian’s team with chief mechanic Clay Smith and driver Troy Ruttman, the Granatelli brothers team from Chicago with driver Jim Rathmann, and Bill Vukovich, the new driver of the Keck “Fuel Injection Special” team. Those teams dominated the 1952 ‘500,’ and among them led all the laps of the race, which Ruttman won after Vukovich’s Kurtis-Kraft roadster broke a steering gear on lap 191.  

Tommy Milton, the first two-time winner of the Indianapolis 500-mile race and the race’s Chief Steward from 1949 through 1952 gave a provocative interview published in the May 1953 issue of Popular Mechanics magazine. that discussed among other subjects, the use of nitromethane.  In the article entitled “The 500 as the Experts See It” Milton and his long-time friend C.W. Van Ranst revealed the details of “the so-called nitro fuel” a product most racing fans knew nothing about in 1953.

Milton explained that nitromethane was added to the base methanol fuel, and stated that the fuel was dangerous, because “the bravest guy will win - the driver who is willing to put the highest percentage of nitro in his fuel will go the fastest until the engine flies apart.” Milton stated that “they” wanted to eliminate nitro, but that “they” would “have a hard time trying to police the ban. No matter how they change the rules the minute the rules are out, everybody goes to work to find out how to beat them.”   

In early 1953, the National Championship Car Owners Association (NCCOA) a group comprised of car owners on the AAA (American Automobile Association) championship circuit led by Ed Walsh started a movement to ban “high explosives in fuel” for the 1953 Indianapolis 500-mile race. The NCCOA sought to ban the use nitromethane, nitrobenzene, nitropropane or “any other liquid explosive” (the powerful Novis used acetone, propylene oxide, benzene, and hydrazine fuel additives) because they thought they were dangerous, but the ban had been not included on the entry blanks sent out for the 1953 International 500-mile Sweepstakes.  

Although three-time ‘500’ winner and Indianapolis Motor Speedway president Wilbur Shaw said that a chemist had told him that nitromethane “in proper hands was not too dangerous,” the Speedway wanted to go along with the car owners group.  Shaw forwarded an agreement to ban the fuel additives to all 83 entrants; acceptance had to be unanimous for the agreement to become effective.

An Associated Press wire story reported on April 30, 1953 that only 73 car owners had signed and returned the agreement, then on May 4 the Indianapolis News sportswriter J. E. O’Brien reported that NCCOA President Walsh of St. Louis, a car owner and partner with Frank Kurtis in Kurtis-Kraft, Incorporated had told the writer that there was one holdout that killed the proposed ban.  

During the 1953 race run on the second-hottest day in race history to that time, fourteen drivers sought relief, sickened by the heat and exhaust fumes and driver Carl Scarborough died of hyperthermia.  The day following the 1953 race, Indianapolis Motor Speedway officials announced their intention to ban “nitro” based on the belief that the fumes from the “nitro” fuel was what had sickened many drivers during the running of the ‘500.’

The 1954 nitromethane ban never came to fruition and nitromethane or nitro compounds continued to be used by many teams that raced at Indianapolis particularly in time trials. It was the advent of turbocharging in the later nineteen sixties that brought the end to use of nitromethane and other exotic fuel additives. With turbocharged engines, mechanics could “turn the screw” on the turbocharger wastegate to increase the turbocharger boost level and create more horsepower with straight methanol.