RACING TO THE FUTURE

The early 20th century’s most demanding touring-car competition – The Prinz Heinrich Trial – forced automakers to redefine performance and durability. Benz & Cie. was a leader in this race within a race

ARTICLE KARL LUDVIGSEN, STEPHAN MCKEOWN
IMAGES: DAIMLER ARCHIVES, KARL LUDVIGSEN

As you cast your eyes over the images of the car on these pages, suspend any attempt to assign a particular time frame to the automobile you see. Its sheer lines, rakish mini fenders and covered wheels hint at the mid-1920s when European automakers were streamlining their creations to outdo rivals in popular races for touring cars. But neither would it be out of place in the context of the 1930s in America, where rakish style was in demand as auto racing gained in appeal.

The Prinz Heinrich Trial

Actually, this car – made by Benz & Cie. in Mannheim – was one of 10 just like it built in 1910 to race in the world’s then-premier contest for touring cars, the Prinz Heinrich Fahrt (Prince Henry Trial), run through the heart of Europe. In 1908, Benz won the first trial, with its star, Fritz Erle, at the wheel. The firm had a reputation to uphold; in the same year, its racers had taken two of the podium places at the French Grand Prix behind a lone Daimler Mercedes.

Prinz Albert Wilhelm Heinrich of Prussia (Prince Henry to his English friends), an enthusiastic motorist and brother of the German kaiser, was credited with introducing motoring to the Prussian royal house, which by 1909 recorded an inventory of 24 automobiles and two trucks in service to the palace. In 1908, Henry put up the prize – a silver trophy of a motorcar – for the inaugural staging of the competition named in his honor. Overseen by the German Imperial Automobile Club, the event was contested over a demanding 1,390-mile route that began in Berlin and ended in Frankfurt. Included were two level sprints and one hill climb. Times set in these contests were rated against bogeys calculated from piston area to determine the number of points awarded, positive or negative. Heavy penalties were triggered by failures on the road sections.

Independent observers noted that the Trial’s results were heavily biased by its speed tests, one of which carried a doubled-points weighting and was used as a tiebreaker among cars with similar points totals. Two such tests were held during the 1910 run, one on a 3.4-mile stretch at Genthin, Germany, soon after departure from Berlin June 2. Competitors headed west to Braunschweig, then south to Kassel and Nürnberg. From there, they turned west toward Stuttgart and Strasbourg, after which a second speed test was held at Heiligkreuz, south of Colmar. The final legs traveled north once again through Metz to Homburg, close to Frankfurt. Entirely in Germany, the 1910 route covered 1,208 miles.

The shape of speed

Such was the importance of this race in promoting a marque’s excellence, that special cars were soon being built to perform well in the speed tests taking full advantage of engine and body design regulations. Narrow chassis were adopted to reduce frontal area, with the cockpit for the mandatory four passengers widened in what was called a “tulip” shape.

The Prince Henry Trial of 1910 marked the event’s apogee as an exploitation of speed. The design of the entries, said one observer, showed “sharply flowing lines, wedge-shaped radiators, lightening holes in hand levers and all other means of taking weight reduction to the limit, minimally sized and downright uncomfortable seats, wire wheels and the like,” showing that “with a few exceptions, these were touring cars in name only.”

Here, few matched Benz’s Georg Diehl and Hans Nibel. Although their entry’s chassis frame was a normal type with a 118-inch wheelbase, it was of unchanging width from front to rear to facilitate the tulip-style body. The Benz machine was shaped with exceptional care, including a drag-reducing tail, smooth flanks and a cowl with narrow aperture covering the standard radiator. Metal shrouds covered the artillery wheels to foil high-speed air turbulence.

An engine for racing

With bore diameter determining piston area and competitive class, six of the 10 special Benz Prinz Heinrich machines had 115 mm bores for 7.3 liters and four had 105 mm bores for 5.7 liters. Each cylinder had four overhead valves v-inclined at a 45-degree included-angle. Twin camshafts in the crankcase operated the valves through pushrods and rocker arms. With a compression ratio of only 4.7:1, the 7.3-liter Benz four produced 118 brake horsepower at 2,100 rpm and was still making 118 brake horsepower at 2,100 rpm.

The fuel mixture came from an updraft carburetor through a well-shaped tubular inlet manifold. The exhaust pipe was carried within the bodywork to minimize drag. Chiefly for reliability, two magnetos fired twin spark plugs, one at the chamber center and one at the side. Coolant circulated only over the upper half of the cylinders, which were cast in pairs with integral heads. Three main bearings carried the crankshaft, driving through a cone clutch to a close-ratio 4-speed gearbox and torque-tube rear axle.

Results and aftermath

Although outmatched in the end by Ferdinand Porsche’s overhead-cam Austro Daimlers, the Benz machines did well in the arduous contest, with seven of the Mannheim entries placing among the top-20 finishers in the highly competitive field. From the Benz team, Erle placed fifth and Arthur Henney finished eighth. In 11th place was Karl Neumaier, who also won the prize given by the city of Braunschweig for the fastest time in the sprints, with a recorded speed of 85.8 miles per hour.

Neumaier’s car – the vehicle seen on these pages –  is one of only two survivors still extant from the original 10 Prinz Heinrich cars, now restored by Mercedes-Benz Classic Center to its original race configuration.

With 1910 as the last year for such exotic entries, the Prince Henry Trials did much to advance state-of-the-art German cars. Said Daimler-Mercedes director Gustav Vischer: “One can say that the type of touring car developed in the Prinz Heinrich Trials has become exemplary for all other nations. Also, even if a marque doesn’t win, the Trial has great value for trade and industry. One can’t exaggerate the value of the publicity that such a great automotive event offers.”

Professor Alois Riedler of the Royal Technical University at Berlin-Charlottenburg had the chance to analyze one of the Prince Henry Benzes in depth. Among his conclusions were the following:

“Under investigation, the Benz car revealed most excellent qualities. The Benz racing motor gives mean specific working pressures … unexcelled even by the highest-class, stationary internal-combustion engines, such as diesel engines for instance. Moreover, the working efficiency is also very high, such as is otherwise only attained by high-powered stationary engines. On the basis of its extensive racing experience, the Benz works has gone almost to the limit of the attainable and has, in particular, reduced the actual [friction] loss to the minimum attainable for the present stage of development of motor construction.”

Added Riedler: “Full account has been taken of the special purpose of the racing-car motor. This, of course, is no longer a motor for ordinary use but adheres closely to the conditions for the cars competing in the Prince Henry competition and is built as a highly developed special motor for short races with the object of attaining the highest output for a brief period.”

Birth of the sports car

For many enthusiasts, the Prinz Heinrich Benz is the very definition of a sports car. Indeed, knowledgeable observers regard 1910 as the year of the sports car’s creation. An initial trio of sporting machines of this new type included the Prinz Heinrich Benz, as well as Porsche’s Austro Daimler, and the Hispano-Suiza T15, introduced around the same time. Based on a racing model, it was best known as the “Alfonso” after Alfonso XIII, the car-mad Spanish king. They were all cars of the future.

The Prinz Heinrich Trial, Europe’s greatest competition for touring cars, led automakers to stretch their minds and skills. Benz & Cie. ace Fritz Erle won the event in 1908.

Car No. 38 at the time of the race.

Car No. 38 today.

Specially prepared Benz touring car No. 38 was driven by Karl Neumaier in the legendary long-distance race in June 1910.

Benz & Cie. entered 10 touring cars in the all-important 1910 Prinz Heinrich Trials, all of which exhibited the firm’s accumulated knowledge in weight reduction and early efforts at streamlining.

The 4-valve, 5.7-liter 4-cylinder engine developed 80 horsepower.

Hand brake and gear lever on outside of sleek body.

Fuel filler hidden under flap.

Snug front cockpit.

Rear cockpit could be covered with a canvas tonneau except when running in the Prinz Heinrich Trial, which required four passengers to be in their seats at all times, one of them an official observer.

Every effort was made to shape a wind-cheating form.

SPECIFICATIONS

1910 Benz "Prinz Heinrich Trial" Special

TYPE: Four-seat roadster

ENGINE: 7,271cc twin camshaft, four 4-valve cylinders in pairs,
single updraft carburetor, dual ignition

TRANSMISSION: Four speeds with gear-selector lever outside cockpit
HORSEPOWER: 118 bhp at 2,100 rpm

BRAKES: Drums on rear axle and transmission brake

SUSPENSION: Solid axles with semi-elliptic springs and torque tube

WHEELBASE: 118 in  CURB WEIGHT: 2,955 lb

TOP SPEED: 84 mph