1936 Hispano Suiza J-12

The Hispano-Suiza was the definitive form of transportation for the well-heeled, discerning clientele of the day. Sometimes called the Type 68, the J12 was introduced in 1931 and offered solely as a rolling chassis in four-wheelbase sizes. The stately coachwork and extensive list of accouterments required a potent twelve-cylinder engine, initially displacing 9.4 liters. The J12 sold well into 1938 until the company returned to aircraft production and armaments.

Magnificently built and magnificently priced, it was among the most expensive French cars built, second only to the Bugatti Royale (of which only seven were built between 1927 and 1933). During the J12 production lifespan, approximately 114 (as many as 120) examples were built. It was the largest and most expensive car ever built by Hispano-Suiza.

Company Origins
Although the J12 was produced in the Bois-Colombes, the northwestern suburbs of Paris, France, Hispano-Suiza was a cosmopolitan marque with Swiss and Spanish origins. Marc Birkigt was a Swiss engineer who designed the Barcelona-built Castro, which became the basis for the first Hispano-Suiza of 1904. As the years progressed, the company produced everything from T-head fours, a water-cooled V-8, and overhead-cam engines. As displacement sizes and the number of cylinders continued to increase during the late 1920s and early 1930s, Mr. Birkigt was determined to build one of his own. Work began in 1929 on what would become the J-12, announced in the Fall of 1931.

The J-12 Engine
The engine powering the Hispano-Suiza J-12 began life as a single 700 lb billet that was machined into a 'square' V12 ('square' due to its bore and stroke size). It used a new design with a bore and stroke of 100mm, convex pistons, and pushrod-operated overhead valves. The twin alloy cylinder blocks were mounted on a common crankcase, and a seven-main-bearing crankshaft with side-by-side connecting rods. The 60-degree V-12 had a compression ratio of 5.0:1, twin Solex downdraft carburetors, a displacement size of 574 cubic inches (9.4 liters), and delivered 220 horsepower at 3,000 RPM. Rubber engine mounts were adopted for the first time. It used a three-speed synchromesh manual gearbox, and Servo-assisted mechanical drum brakes resided behind each wheel.

Two J-12 vehicles were fitted with long-stroke engines with an 11.3-liter displacement size and delivering 250 horsepower. Several J12s were later upgraded with this larger engine.

The suspension was comprised of semi-elliptical leaf springs all around, with a solid front and live rear axle. Wheelbase sizes included 135-, 146-, 150, and 158-inch options.

All Hispano-Suizas were coachbuilt by the finest European carrosseries, including Vanvooren, Fernandez and Darrin, Saoutchik, Binder, deVilalrs, Kellner, D'Ieteren, and Letourner et Marchand.

by Daniel Vaughan | Oct 2023