20-04-2019, 07:56 AM
(This post was last modified: 20-04-2019, 07:58 AM by Tony Press.)
The 'Austin Seven Companion' has a good article on the four cylinder Austin Seven engine 'Brough Superior Four' by G Gordon May 1969 starting on page 14.
It seems the original radiator design shown in the cutaway above was changed to a more open set up with a round tank and water pump following cooling problems.
They were apparently built from 1933 using a standard Seven engines bored to 800cc.
As shown the other earlier four cylinder Broughs were not fitted with Austin Seven engines.
Wikipedia has an entry broadly agreeing with this -
"George Brough considered the four-cylinder engine ideal for a motorcycle, given its smooth running and potential for greater horsepower than a single or twin-cylinder engine of the same capacity. Brough Superior had already revealed two prototype 4-cylinder machines before 1932, using an air-cooled sidevalve V-4 built in-house (1927), and an air-cooled inline sidevalve 4 developed by Motosacoche (1928).[3] While these prototypes were never built in series, they generated tremendous attention at shows and in the press . In 1930, George Brough considered using an engine already in production, in this case the well-developed Austin 4-cylinder sidevalve, water-cooled motor of 747cc. Brough increased the engine displacement by a 50 cc to 797 cc and added a light alloy 'sports' cylinder head for more horsepower. George Brough claimed a significant increase in the Austin's power output, but, as The Motor Cycle magazine observed, this was a luxury motorcycle intended for use with a sidecar, not a sports machine"
It seems the original radiator design shown in the cutaway above was changed to a more open set up with a round tank and water pump following cooling problems.
They were apparently built from 1933 using a standard Seven engines bored to 800cc.
As shown the other earlier four cylinder Broughs were not fitted with Austin Seven engines.
Wikipedia has an entry broadly agreeing with this -
"George Brough considered the four-cylinder engine ideal for a motorcycle, given its smooth running and potential for greater horsepower than a single or twin-cylinder engine of the same capacity. Brough Superior had already revealed two prototype 4-cylinder machines before 1932, using an air-cooled sidevalve V-4 built in-house (1927), and an air-cooled inline sidevalve 4 developed by Motosacoche (1928).[3] While these prototypes were never built in series, they generated tremendous attention at shows and in the press . In 1930, George Brough considered using an engine already in production, in this case the well-developed Austin 4-cylinder sidevalve, water-cooled motor of 747cc. Brough increased the engine displacement by a 50 cc to 797 cc and added a light alloy 'sports' cylinder head for more horsepower. George Brough claimed a significant increase in the Austin's power output, but, as The Motor Cycle magazine observed, this was a luxury motorcycle intended for use with a sidecar, not a sports machine"