Hispano-Suiza H6

Hispano-Suiza H6
Hispano-Suiza 1924 H6B Million-Guiet Dual-Cowl Phaeton.
Overview
Manufacturer	Hispano-Suiza
Production	1919–1933
Designer	Marc Birkigt
Body and chassis
Class	Luxury car
Layout	FMR layout
Powertrain
Engine	6597 cc straight-6 7983 cc straight-6
Transmission	3-speed manual
Chronology
Successor	Hispano-Suiza J12

The Hispano-Suiza H6 is a luxury car that was produced by Hispano-Suiza, mostly in France. Introduced at the 1919 Paris Motor Show, the H6 was produced until 1933. Roughly 2,350 H6, H6B, and H6C cars were produced in total.

The H6 engine featured a straight-six engine inspired by designer Marc Birkigt's work on aircraft engines. It was an all-aluminium engine displacing 6,597 cubic centimetres (403 cu in). Apart from the new overhead camshaft, it was essentially half of Birkigt's aviation V12 design. The seven-bearingcrankshaft was milled from a 600 lb (272 kg) steel billet to become a sturdy 35 lb (16 kg) unit, while the block used screwed-in steel liners, and the water passages were enamelled to prevent corrosion.

One of the most notable features of the H6 was its brakes. They were light-alloy drums on all four wheels with power-assistthe first in the industry, driven with a special shaft from the transmission. When the car was decelerating, its own momentum drove the brake servo to provide additional power. This technology was later licensed to other manufacturers, including arch-rival Rolls-Royce.

The 1922 H6B was slightly more powerful. An 8.0 litres (488 cu in) (110 by 140 mm (4.3 by 5.5 in)) engine was used in 1924's H6C.

The H6 series was replaced in 1933 by the J12, which initially used a 9.5 litres (580 cu in) V12 pushrod engine.

A series of five racing H6Bs with short wheelbases and slightly enlarged engines was built in 1922. These were referred to as "Boulogne", to celebrate the H6's triple victory at the sports car race at Boulogne by pilots Dubonnet, Garnier & Boyriven in 1923 (Journal des debats, July 27, 1923).Woolf Barnato piloted a Boulogne to eight international records, including a 92 mph (148 km/h) average over 300 mi (480 km), at Brooklands in 1924.