Ernest Henry (born 1885, Geneva, Switzerland – died 1950, Paris, France) was a mechanical engineer. He developed auto racing engines, and is especially well known for his work for Peugeot and Ballot, who dominated motor-racing 1912 to 1921. His design directly influenced Sunbeam Racing cars as early as 1914; the 1921 Grand Prix Sunbeams owe much to his work with Ballot and the 1922 Grand Prix Sunbeams were designed by him.

His engine architecture was the precursor of modern engines. One biographer called him “perhaps the most brilliant engine designer ever”; another described one of his designs as “so technically advanced it could have landed from outer space”. Henry’s “theory, design and execution” of twin-cam engines was to guide engine development in Europe and then around the world for the next century.

Early life and Education

After studying Applied Mechanics at Technicum (School of Engineering) in Geneva, Ernest Henry worked from 1906 on marine engines for Picker of Geneva, then moved to Paris in 1909, serving the Motos Labor manufacturing company (marine and aviation engines), before joining the ranks of Peugeot in 1911.

Peugeot

Henry became part of “Les Charlatans” (a name given by the Peugeot factory in Beaulieu who were opposed to the conception of race car along the Henry style) with Jules Goux, Georges Boillot and Paul Zuccarelli (who had left Hispano-Suiza). This group had convinced Robert Peugeot, whose firm Lion-Peugeot had, in 1910, merged with institutions Peugeot of Audincourt, to engage in the study and the financing of a project race car for the Grand Prix of the Automobile Club de France (ACF) and the Coupe de l’Auto of 1912.

Ernest Henry, who was then 27 years old, started in the racing department, in Suresnes (in Rossel’s former factory). The engine born in early 1912 featured double over head camshaft with a bevel at each end, inclined actuating four valves for each of the four cylinders and hemispherical combustion chambers. The chassis of this car was light and had good road manners and quickly became the car to beat; it could reach 190 km/h (120 mph).

These cars would be entered at the French Grand Prix: the type L76 (L for Lion) unlimited class, with a displacement of 7.6 liters, and the type L3 for three-liter restricted Coupe de l’Auto competition.

Peugeot L76 and L3 emerged as winners of the 1912 French Grand Prix in Dieppe, the Mont Ventoux Hill Climb, the Coupe de l’Auto, Circuit of Ardennes, and Coupe de la Sarthe.

With these engines, Ernest Henry may claim a paternity landmark in the history of the automobile. They are not the first “4 valves per cylinder” or the first “dual overhead cam head,” but they are the first in the world to combine the two techniques. All the most powerful racing engines, to the current Formula 1 recapitulate this formula, which is now becoming universal in production automobiles.

In 1913, the 5.6 liter and 3 liter engines were further developed with camshaft timing, previously carried by shaft and bevel, now carried out by a cascade of gears, and lubrication was amended by adding a dry sump.

 1913 May 30 Jules Goux driving a L76, won the 1913 Indianapolis 500, 804.5 km at an average 122.155 km/h. This was the first victory for a European car in the Indianapolis 500, and had a considerable impact on both sides of the Atlantic.

The new 5.6 liter took first and second place at the French Grand Prix, won at Mont Ventoux, and a streamlined L76 set a new world record speed of 170.94 km/h at Brooklands Motor Circuit and won several other records on the same circuit in the hands of Goux and Boillot.

In the 1914 Indianapolis 500, 2.5 liter and 4.5 liter engines were installed, while maintaining the same technical design. Peugeot took second and fourth place despite tyre problems; Arthur Duray in the 3 liter class and Jules Goux in the 5.6 liter class.

Georges Boillot in a Peugeot lead the Mercedes team with his 4.5 liter Henry engine until the last lap of the historic 1914 French Grand Prix run July 4, 1914, a month before the First World War. He dropped out, after taking serious risks, due to the many stops caused by defective tyres.

In the 1915 Indianapolis 500, Peugeot placed second with the same type vehicle as that of 1914, with the 4.5 l engine, driven by Dario Resta and won the 1916 Indianapolis 500 at an average speed of 133.994 km/h. Peugeot’s third victory at Indianapolis was won in 1919 when the glorious 1914 4.5lt driven by Howard Wilcox and Jules Goux took first and third place respectively. The L2.5 won the Targa Florio in 1919.

The technical advances of Henry’s engine designs allowed them to win races five years after their creation. These performances were not to remain without notice in the United States. Peugeot’s engine design had a lasting influence on U.S. engineers for many years. Cars from previous campaigns remained in the United States, and were sold to American drivers, among them Harry Arminius Miller who would soon copy this exceptional mechanical architecture, then after the bankruptcy of Miller, Fred Offenhauser who was one of Miller’s employees in the 1930s continued the use of this design. This type of engine in 4 cylinders form was used until the end of the 1970s, with the final win at Indy by an Offenhauser in 1976.

Ernest Henry left Peugeot in February 1915, replaced by the engineer Marcel Grémillon who developed a 1-liter, five valve per cylinder, triple overhead cam engine in 1920-1921.

Looking back at Henry’s time at Peugeot, a writer in 1921 said his cars “won practically all races in which they were entered”.

Post-WWI

At the end of the World War I in December 1918, the pilot René Thomas and Ernest Henry offer to Ernest Maurice Ballot study racecar Ernest Henry made during the war. The latter accepted aiming to participate in the 1919 Indianapolis 500, the first post-war Indianapolis race.

Ernest Henry had 101 days (it was in fact necessary to leave Paris no later than April 26, 1919 in order not to miss the boat) to finalize its design and create 4 complete cars for this event.

These four Ballot cars, which were designed in the utmost secrecy, resembled pre-war Peugeots but improved to a straight-eight engine capable of 2900 RPM and giving 150 hp for a top speed of nearly 200 kilometers per hour (120 mph). The straight-eight engine architecture was quickly adopted in the world of motor sport (in 1921 more than half of Indianapolis contestants were straight-eights).

However, during the 1919 race, repeated tyre and wheel problems did not allow the high expectations set in testing. Albert Guyot finished in fourth place behind two Henry engined Peugeots and a Stutz.

The formula used for the 1920 Indianapolis 500 limited the displacement to 3 liters, so Ernest Henry conceived, according to the same architecture, a new straight-eight engine of 2.97 liter displacement. The maximum speed of the car was slightly reduced to 180 kilometres per hour (110 mph), but the usability further improved, and this time the Ballot entries finished second, fifth and seventh.

Ballot was the only French marque to represent France at the 1921 French Grand Prix at Le Mans in July, with three eight-cylinder cars and a new four-cylinder 2 liter engine designed by Ernest Henry. De Palma finished second behind the Duesenberg driven by the American Jimmy Murphy. The British STD Combine was represented by two Talbot and two Talbot Darracq- all four were in fact, Sunbeam Grand Prix the design of which was largely Henry’s.

After this exploit Ballot, dubbed by Charles Faroux, ‘the father of two liters’, decided to build the series which was to be the LS type 2, with a 2 liter four-cylinder engine with a two-camshaft, 8-valve head, which he continued manufacturing until 1924, despite its high price due to its refined design and careful construction.

Also in 1921, the 8-cylinders distinguished themselves at the Italian Grand Prix at Brescia and won by Jules Goux on a Ballot 3 l.

Ernest Henry left for Sunbeam-Talbot-Darracq in December 1921, following an offer of Louis Coatalen to design the Sunbeam 2-liter Grand Prix in 1922. He directed the racing team group, in Suresnes. He then moved to the automaker Omega, it appears he left in 1924.

Later Life

Henry’s later life is less well known. He worked as a craftsman at home, and it seems that he did no more engine design. At the time of his death in 1950 at the age of sixty-five years, he worked in an engineering company Levallois near Paris.

Motorcycle Engine

In 1914 Henry designed a 500 cc straight-twin engine for the Peugeot 500 M racing motorcycle department, derived from two 250 cc cylinders of his auto engine design. It had the following technical characteristics: double overhead cam head, actuated by a cascade of gears, 4 valves per cylinder. The engine was very sophisticated for the time and proved to be fragile in use, but very powerful.

Edited from the Ernest Henry Wikipedia Article