A Brief History of the Marque
In 1912 Ronald Charteris founded the All British Engine Company in Hersham, Surrey with Granville Bradshaw as chief engineer, and later changed the name to A.B.C. Motors, Ltd. During the Great War they produced horizontally opposed twins for Sopwith, and used a development of this engine in a motorcycle in 1918, pre-empting the BMW design by several years. (Bradshaw was not amused by BMW's use of his design and took them to task in 1926. This would not be the last time BMW "acquired" a British inventor's design.)
The Sopwith Aviation-built ABC flat-twin was a 398cc ohv with wet sump lubrication and a four speed gearbox. It was a very advanced motorcycle which sported a duplex cradle frame, front and rear suspension and internal expanding drum brakes. Gnome & Rhone produced an improved 493cc version of this machine under license until 1925.
In the same period they produced some of the earliest scooters, the Skootamota, powered by an OHV 125cc engine which sat above the rear wheel delivering its power by chain. Bradshaw's ABC company built motorcycles in Britain until 1923, and also in Germany until 1925. They were not related to the Birmingham based ABC company which produced belt-driven Villiers-powered machines from 1922 to 1924.
Reports on machines at the 1926 Olympia Show
The new Bradshaw effort is, of course, referred to, and as is usual with this gentleman's productions, a furore of excitement and interest is anticipated. As is well known, this is a 250 c.c. V twin with 4 speeds, arranged somewhat on the lines of the late lamented A.B.C. Further to add to its interest is the price, which will be in the neighbourhood of ...
From Motor Sport Magazine of that year.
Inclined over-head valves and oil-cooling are distinctly modern items in the 500 c.c. Bradshaw flat twin engine. Oil spray supplied by a mechanical pump is continually splashing on to the enclosed cylinder barrels, the under-sides of the pistons, the valve-gear, etc. The inlet manifold cast with the crank case is also indicated.
The Motor Cycle March 16th, 1922. Page 324.
More on the Bradshaw Engine
Bradshaw engines included oil-cooled singles and HO twins, and the Omega rotary.
There is an article by Roy Bacon on the very unconventional Omega here:
micapeak.com/winona/strange/omega.html, and a fairly humorous account by Patrick Head about testing one of
these engines here:
www.grandprix.com/ft/ft00203.html
Bradshaw engines were used in many vintage motorcycles including OK-Supreme, Omega, Orbit, Sparkbrook and Zenith.
Sources: Motor Sport Magazine, et al
Fri Oct 05 2012
noelkerrigan<at>hotmail.co.uk
bradshaw engine.
76543 34567
have a friend with complete engine. it turns over. is it worth much. think
it is the oil cooled 350..
gb
Tue Feb 06 2007
pflowbikes at worldonline.co.za
Engine spares
Bradshaw 350cc oil-cooled
I have been given a 1920-era Bradshaw 350cc oil-cooled engine.
It has unfortunately broken a con-rod and damaged the engine casings.
It is therefore missing a con-rod, and it's also missing the tappets and
pushrods. Otherwise, everything is there. I would like to know if you could
put me in touch with anyone who may have a spare Bradshaw engine casing
or any other parts from an engine they are breaking up.
Durban, South Africa
.........
Thanks for your prompt response - something we're not used to in South Africa!
I do have some pix and have attached them.
A little bit of tech info. - I don't know if you keep records such as this, but I have noticed that a few websites state that the Bradshaw oil-cooled engine had a pressure-fed big-end and that the sleeve was cooled by splash-feed from the crankshaft. In fact, the exact opposite is true - the engine has a splash-fed plain bearing big-end (white metal bearing) with a scoop in the con-rod, and the oil pump exists only to pump oil from the sump into an annular groove which runs around the top of the sleeve. The engine being a wet-sleeve design, the oil simply ran uniformly down the outside of the sleeve and dripped back into the sump.
I appreciate your help in the matter - thank you!
Regards
Brett Clark
