Thursday, May 5, 2016

Persistence - the Rudolph Wehr story 
part two 

Throughout the long history of American automobile racing, few men have personified persistence as did Rudolph K. B. Wehr. The previous chapter dealt with Wehr’s efforts through 1932;  this chapter will pick up with his entries for the 1934 Indianapolis 500 and carry through his last Indianapolis attempt in 1940.   

1934 Indianapolis 500 

Sometime after the running of the 1933 Indianapolis ‘500’ Wehr purchased the two quasi-factory Hudson entries built by former driver Russell G. “Buddy” Marr, an employee of the Hudson factory experimental department. In 1928, Marr successfully qualified the #35 supercharged Miller owned by B.W. Cooke owner of the Chicago based Coyne Electrical School for the ‘500’ field at 109.685 MPH. Marr was scheduled to start 28th in the 1928 ‘500,’ but the day before the race, his designated relief driver, a 25-year old rookie driver named Clarence “Chet” Miller took the car out for practice and crashed which damaged the Miller beyond repair.  Marr evidently held no ill will towards Chet Miller, as Miller drove Marr’s Hudson entries in the 1931, 1932 and 1933 Indianapolis 500-mile races, the last two teamed with the unrelated Allen Miller. 

Willard Prentiss looks over the Wehr powerplant in 1934
photo courtesy of the Indianapolis Motor Speedway collection
IUPUI University Library Center for Digital Studies 

Denver driver Willard Prentiss was the nominated driver of the #64 ‘Wehr Rotary Valve Special’ for the 1934 Indianapolis 500 powered by a Wehr rotary valve engine the details of which are unknown to the author. After the Wehr car proved to be too slow, Prentiss replaced Lockbourne, Ohio’s Bill Chittum as the driver of the #59 “G & P Hudson Special.” Prentiss qualified on May 28th with a 107.797 MPH average for his 25-mile time trial run, initially good enough for the 30th starting position, but he was later bumped and wound up on Race Day as the first alternate.

 1937 Indianapolis 500

Three years passed before Rudolph Wehr made another Indianapolis attempt, when he posted two entries for the 25th running of the International 500-mile Sweepstakes.  The two Hudson chassis, fitted with new awkward-looking grille shells, were powered by all-new 4-cylinder two-cycle supercharged rotary valve engines. There had been previous experiments with two-cycle engines at the Indianapolis Motor Speedway first with Fred Duesenberg’s factory two-cycle entry for the 1926 ‘500’, followed by Leon Duray’s 1931 supercharged “U” (cylinder side-by-side) 16-cylinder monster, and Clessie Cummins’ 1934 oil-burning two-cycle experiment, all of which were later deemed failures by their builders.

The June 1937 issue of the Automotive Trade Journal provided technical details of the Wehr entries. Each cylinder of the Wehr engine measured a 4-inch bore while the piston had a 4 ¼-inch stroke for a total engine displacement of 213 cubic inches. The rear-mounted Roots supercharger was fed by a single Winfield down-draft carburetor, with the fuel mixture ignited by Champion Spark plugs supplied energy through Packard ignition cables from the Bosch magneto. Each wheel of the 1931 Hudson chassis was equipped a Hartford-Fageol friction disk shock absorber from Oakland California and mechanical brakes, and each car weighed 1986 pounds dry.     

A May 19, 1937 article in the Indianapolis Star explained the advantage of the unique rotary valve design as “it eliminates most of the up-and-down motion in the motor, except that of the pistons. The two-cycle engine is intended get twice the explosions that a four-cycle engine. The rotary valves, according to the inventor, do away with much of the intricate machinery of the engine and do not even require a camshaft in the motor. According to experts, the principle is perfect, but it merely doesn't function.” 

"When it does work," proclaimed Wehr, "I will have done away with all valve trouble not only in automobiles but also in airplanes. It will make plane travel safer than ever.” The Star article went on to state that Wehr’s “principal fear was that the motor will become overheated. Since bringing the two cars here several weeks ago he has spent hours in the garages trying to overcome his problem and has signed up two drivers to qualify them.”

The drivers were identified in the Star as Frank Wearne and Thomas Cosman, described as “two newcomers to Indianapolis who have been racing on the Pacific Coast for several years. Both are inclined mechanically and are working with Wehr in ironing out his problems.”  "I don't expect to set any speed records with my cars," Wehr said, "All I want to do is make them run fast enough to qualify, say around 114 miles an hour. I want my rotary valve and two-cycle engine to run in the race."

The May 19 1937 Indianapolis Star article wrapped up with a depressing recounting of Wehr’s history with rotary valves at the Speedway which began “in 1916 when Wehr built his first rotary valve motor for a racing automobile. It failed.” After the historical recap, the article closed by stating that “these are the one hundred and seventh (107) and one hundred and eighth (108) engines that Wehr has built with rotary valves. Not one has worked.”  Rudolph Wehr was persistent if nothing else.

According to the author’s friend and fellow racing historian Jim Thurman, Thomas Charles “Tommy” Cosman, born on May 13 1908 in Pennsylvania, had a decent racing career in California, twice finishing in the top 30 (28th in 1933) (35 in 1934) in AAA Pacific Coast points, and apparently finished 11th in the 1933 Legion Ascot "Class B" classification. When not racing, Cosman ran a car wrecking business, and after he failed to qualify the #63 ‘Wehr 2-cycle Rotary Valve Special’ for the 1937 ‘500,’ he never returned to the Speedway. Cosman passed away in 1973 and is buried in Whittier California.

Frank Wearne in 1939 
photo courtesy of the Indianapolis Motor Speedway collection
IUPUI University Library Center for Digital Studies 

Frank Wearne was another Legion Ascot veteran who for a period drove the Frank Kurtis-bodied ‘Atlas Chrome Special,’ one of the top rides on the AAA Pacific Coast ‘big car’ circuit. After his #64 ‘Wehr 2-cycle Rotary Valve Special’ was withdrawn during the month of May with terminal engine problems, Wearne picked up the ride in Leon Duray’s Miller-powered Stevens chassis for his first Indianapolis ‘500’ start.  Wearne went on to race in seven consecutive Indianapolis 500-mile races, with his best finish of seventh in the “Boyle Valve Special” Stevens-Miller in 1940.  

While the author does not profess to be expert on the theories of the operation of an internal combustion engine, it appears as though a rotary valve design could have several significant advantages over a conventional poppet valve train. The rotary valve assembly is less complex and more compact than a conventional pushrod system, which would result in a lighter weight cylinder head.

The rotary valve engine would have the potential for a higher compression ratio and without the weak point of valve springs, the engine could turn more revolutions per minutes (RPM) than a conventional design. However, the rotary valves cylinder head design would require special attention to valve lubrication and cooling to prevent the valve from overheating.  Valve overheating was apparently the problem with which Wehr most struggled, the failure of which newspapers referred to as “frozen valves” and catastrophic engine failures.  

1939 Indianapolis 500 

For his fifth Indianapolis entry in 1939, Rudolph Wehr and his new partner, Edwin Anderson entered the #23 “Wehr-Anderson Rotary Valve Special” powered by a supercharged four-cylinder four-stoke rotary valve 181 cubic inch engine without a driver named. The 1939 chassis which weighed a hefty 2021 pounds, rode on 18-inch wheels, and carried 4-wheel hydraulic brakes and Delco shock absorbers with the engine fed by a single “Speed” side-draft carburetor and the Roots-type centrifugal supercharger.    

Author's copy of the 1939 AAA technical specifications sheet
 for the Wehr-Anderson Rotary Valve Special 

George Robson a rookie driver from Huntington Beach California took his rookie test in the “Wehr-Anderson Rotary Valve Special,” and then drove it in practice. Towards the end of the month of May the Indianapolis Star newspaper proclaimed that “if she (the car) manages to go all the way through the race, Robson will earn the undying gratitude of a man (Wehr) who has stuck with an idea despite obstacles which would have throttled the ordinary person years and years ago.” Alas, by the final day of qualifying, Robson abandoned Wehr’s rotary valve entry for a more competitive machine. 

George was the eldest of the three racing Robson brothers, born in Newcastle England in February 1909, before the Robson family relocated to Canada and eventually in Huntington Beach California around 1924. Harold Junior “Hal” was born in Canada in 1911, followed by James “Jimmy,” born in 1917, Albert, and the family’s youngest child, daughter Amy. All the brothers worked in their father Harold’s machine shop, Robson Engineering, and three of the brothers- George, Hall and Jimmy- raced. 

The two older Robson brothers both began racing in 1930 but eventually the Robson trio advanced to race “big cars” up and down the West Coast, particularly at the half-mile dirt Southern Ascot Speedway in South Gate, the third Los Angeles area “Ascot” track which operated from 1937 until the cessation of racing due to World War 2 in 1942.

George Robson 1941 Maserati 
photo courtesy of the Indianapolis Motor Speedway collection
IUPUI University Library Center for Digital Studies 

On the final day of 1939 Indianapolis ‘500’ time trials, George qualified Artha B “Deacon” Litz’ Maserati for the starting field with a 4-lap time trial run that averaged 116.305 MPH for the 28th spot but was the slowest car in the field. Litz’ Maserati Tipo V8RI, chassis # 4501, was powered by an unsupercharged 4 ½ liter (270 cubic inch) V-8 engine fed by four Linkert motorcycle-type carburetors. The 225-pound Litz (billed as the “biggest race car driver in the world”) had earlier abandoned his own entry in favor of Dick Wharton’s similar Maserati Tipo V8RI chassis #4502 powered by a supercharged 3-liter (182 cubic inch) engine that Litz qualified for the starting field at 117.979 MPH.

Louis Tomei easily qualified Frank Griswold’s supercharged 8-cylinder Alfa Romeo for the final starting spot with a run of 118.454 MPH and the field was filled. Billy Devore, the son of racer Earl Devore, in Leon Duray’s four-cylinder supercharged ‘Barbasol Special’ made a qualifying attempt, but during his run the brake handle broke and he coasted over the last lap and posted a four-lap average of 104 MPH, below the required 110 MPH minimum. Mechanics quickly repaired Devore’s car, but he stalled as he left the pit area for second attempt.

Duray’s mechanics pulled the car back, restarted it and Devore was pushed off just two minutes before the final gun sounded to end time trials. Devore’s first lap was too slow at 115.207 MPH, but over the next three laps Devore picked up his pace and completed his 10-mile time trial run with an average speed of 116.527 MPH, and “crowded out,” or bumped, George Robson out of the field. All this exciting action occurred while the “Wehr-Anderson Rotary Valve Special” sat in the dark inside garage #17 and once again in 1937 Rudolph Wehr’s creation missed “the big show.”

George Robson would qualify for the Indianapolis ‘500’ starting field again in 1940 and 1941, then he was joined in the 1946 ‘500’ by younger brother Hal.  Jimmy Robson never made it to Indianapolis, as he retired from race driving after he suffered severe injuries in an American Racing Association (ARA) “big car” crash in 1941 at the high-banked Oakland Speedway as he practiced for a Labor Day 500-lap race.

Hal Robson at Funk's Speedway in 1948
author's collection

George Robson, the surprising 1946 ‘500’ champion, was killed during a 100-lap race at Georgia’s dusty Lakewood Speedway on September 2 1946 in an accident that also killed George Barringer.  According to historian Norm Bogan, Hal Robson was originally scheduled to drive the #7 Wolfe Special in place of Barringer.

1940 Indianapolis 500

Rudolph Wehr and partner Edwin Anderson’s entry of their #51 “Wehr & Anderson Special” for the 29th running of the International 500-Mile Sweepstakes was received in the Speedway offices on May 2.  The same machine as the 1939 entry, the entry blank arrived at the Speedway without a driver named, but the following day, Emrel Gene “Port” DeFraties, a one-time outlaw “big car” racer during the nineteen thirties on the Illinois and Kansas fairground circuits, was named as the driver. “Port” practiced the “Wehr & Anderson Special” but never made a qualifying attempt.   

Later after he retired from driving, DeFraties became a traveling announcer with the AAA Midwest midget circuit before he started his own hardtop sanctioning body in 1949. Through the nineteen fifties the “DeFraties Circuit” made weekly stops during the racing season at track located in Springfield, Farmer City, Macon, Lincoln, Mazon, and Peoria Illinois. 

Rudolph Wehr never returned to the Indianapolis Motor Speedway after his sixth failed attempt to qualify a car in 1940, but he had established a record of persistence in the face of adversity. 

Rotary valve development after Indy by Wehr and others 

The author found a reference to Rudolph Wehr in Paul Smith’s book Merchants of Speed which a stoty that in 1953 Chet Herbert found a Wehr 183-cubic inch rotary valve two-cycle four-cylinder engine in a junkyard that he planned to use a power plant for his Bonneville car.

Herbert found the engine had 14:1 compression ratio and used piston rings to seal the rotary valves a system which did not work (Wehr’s final patent #2368956 attempted to address the sealing issue).  Chet fitted the Wehr engine with a hydraulic-actuated tapered cone system of his own design to seal the rotary valves and fitted the engine with a GMC supercharger. During testing the revamped engine reportedly self-destructed on the dynamometer.

The book erroneously attributes to engine to an Wehr 1932 Indianapolis attempt, which of course did not occur.  Most likely what Herbert found was the 1932 Legion Ascot ‘big car’ engine although that engine was not described as a two-cycle engine. 

The Crosley rotary valve engine 
the author suspects this was Wehr's work 

According to Daniel Strohl’s article in the February 2016 issue of Hemmings’ Classic Car magazine after World War 2, Rudolph Wehr worked to develop a rotary valve cylinder head for the Crosley overhead valve four-cylinder engine for midget racing, an example of which the author believes  is on display at the Museum of American Speed.

Photo of Wehr patterns by Daniel Strohl 

Daniel Strohl also reported that a number of Wehr’s parts and wooden patterns were offered for sale by Wehr family members at the October 2015 Hershey, Pennsylvania Antique Automobile Club of America (AACA) swap meet.  The author would appreciate any leads to these sellers, as he would like to obtain one of these patterns - please contact the author at

Smith's rotary valve patent drawing

In the nineteen thirties San Angelo Texas inventor Thomas Noah Smith developed a rotary valve system which  received US patent 2336756 in 1943.  However this is not "true" rotary valve system, as the rotary valves work in concert with a center "master" poppet valve. Smith had a big car built by Harry Lewis (who also built Ted Horn's "Baby" big car) which reportedly raced only once before it was parked in a garage in San Antonio for 50 years. The restored Smith car resides in Ed Justice's museum.   

exploded view of Rotax 532 

In the modern era, Austrian engine manufacturer Rotax used rotary intake valves in their now out-of-production two-cylinder two-stroke 31 cubic inch engine design the 532 for ultralight aircraft and continues to use rotary intake valves in the 532's larger successor, the 36 cubic inch Rotax 582

Coates International Limited currently builds and markets the Coates C86GE engine-generator system which with a 855-cubic inch displacement Inline 6-cylinder engine which can run on natural gas, propane, digested land fill gas, hydrogen, and other fuels such as diesel which the manufacturer claims can develop up to 400 horsepower. The engine uses the” Coates Spherical Rotary Valve System” which replaces the poppet valve system with a pair of rotary valves (one intake and one outlet) operated by overhead shafts.  

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