Today in Motorcycle History

Weslake Motorcycles

Harry Weslake was born in Exeter in 1897. His father Henry directed Willey and Co, an engineering company in Exeter which supplied gas meters to the industry - at the time, most of the heating and lighting was by coal gas.

At the age of 15 he blew his life savings on a pair of goggles, hired a motorcycle and puttered off into the blue yonder until stopped by Mr Plod, who waggled his finger and sent him home.

With the onset of war, against his family's wishes he joined the Royal Flying Corps.

Whilst still enlisted he took out a patent on a carburettor. The Wex carburettor by Weslake of Exeter may be something of a tongue twister, but it worked well. Harry was 18.

By the early 1920s he had his own workshop and became interested in why two seemingly identical engines would perform very differently, so he applied the skills he had learned whilst working with his father, a gas engineer, to discovering the secrets of induction. He gas-flowed the heads, in the process creating one of the most important engine development techniques.

Over the following decades and during the second war Harry worked with numerous companies in the automotive field including W. O. Bentley (a fellow motorcyclist, of Australian parentage), SS Cars and later Jaguar, Austin, Citroen, and Armstong Siddeley. He also worked with Riley, who did not have the good grace to appreciate him.

Postwar he formed Weslake and Co. Ltd. and provided cylinder heads for the Ford GT40 Le Mans cars which famously trounced Enzo's Ferraris in 1966, finishing first, second and third. [1]

In the 1970s his motorcycle speedway engines had become very successful, winning the 1976 world speedway championship. Two years later in the '78 championship Weslakes took 2nd, 3rd, 4th and 5th place, with a delighted Harry looking on. He collapsed that evening and died happy.

Weslake Timeline

1. Ford vs Ferrari is a 2019 film which scores 8.2 on IMDB and 92% on Rotten Tomatoes. The true story behind the film is related concisely by Time Magazine

Flylow at mtaonline.net
Westlake dual cam four valve
Is there a manual or illustration of this engine that I can purchase???
John Filo
Alaska United states

Nothing listed, but If you find a source, please share. Try this page: Books and Manuals
Flylow at mtaonline.net
A lot of unknowns. 500 cc 4 valve Engine. Engine numbers- 3986.1.L.P.A. Model B85 8 S 85 9. There are two valves at bottom of motor for oil drain into collector can but how do they work? an they be removed? Is there a shop manual for this motor ?
John Filo
Alaska - USA

Wed May 18 2016
ernest.healy at monash.edu
weslake 1976?
I need to replace a cracked piston in a 4 valve Weslake speedway motor. However, the distance between the centre of the gudgeon pin and the piston deck is greater than the Weslake replacement pistons that are currently readily available. Can you please tell me if Weslake changed their piston specifications at some point in time? I was told the engine was bought from Rickard Helsen in the late 1970s and has an unusual serial number: X 66. If I were to use the readily available Weslake replacement piston, the compression ration would be far too low because of the lower piston crown height.
Melbourne Australia

Tue Jul 07 2009
scroft9959 at hotmail dot com


Double Overhead Cam
Many variations incuding belt, chain and bevel drive

Looking for a DOHC Weslake for a private collection!

Wondered if you can help?
North West UK

Sat May 23 2009
johnnytt50033 at aol.com
weslake 500cc ID
weslake 275 6190MS B858 S859
Need help with engine ID re year made ....This pic is in california.
Calif U.S.A

If you have a query or information about Weslake motorcycles please contact us