Lister 5/1 Diesel

Sir Harry Ricardo

Information on the prominent British Engineer


Information, pictures and site link by kind permission of, and © Ricardo Consulting Engineers Ltd


Sir Harry Ricardo

Harry Ricardo was one of the all-time great engine development engineers, founding the company which still bears his name, Ricardo Consulting Engineers Ltd. Born in 1885, he went to Rugby, Cambridge and then Trinity College. His interest in engines was to form into a long career, which led to his company becoming one of the worlds best-known development companies in both petrol and diesel technology.

At the age of 17, he started a small engine production company: 'The Two-Stroke Engine Company' to manufacture and sell a car which used an engine that he had designed. The Dolphin engine became very popular with marine users, and found its way into most of the of the local boats in the Shoreham area (South Coast of Britain, west of Brighton) where Sir Harry was based.

Dolphin Engine
The Ricardo Dolphin Two-Stroke Engine

Work followed for the Royal Naval Air Service (RNAS) on various projects, and a new design of engine for one of the army tanks of the day led to further recognition within the UK engine industry, and Sir Harry bought the site of the present headquarters out of the proceeds of the tank contract in 1919.

Medium Mk B Tank
The Ricardo Engined Medium Mark B Tank. (Harry Ricardo is third from the left)

He is probably best know for the Ricardo 'Comet' diesel injection pre-chamber, of which millions have been produced under licence and by copying. The work and patent was to have a huge impact on the emergent diesel engine technology, and was to be a significant development both in Europe and the USA. The Citroën 'Rosalie' car was the world's first production diesel car, with the engine featuring a design incorporating the Ricardo 'Comet' MkIII combustion chamber.

Comet Patent
Copy of the Patent for the Comet combustion chamber

1935 Citroën 'Rosalie' Car
1935 Citroën 'Rosalie' Car

He also worked on the problems of pre-ignition in petrol engines, so called 'knocking' or 'pinking', and this led to the establishment of a unique test facility, with variable compression test engine and dynamometer rig, the fore-runner of every test-cell in use today. The establishment of the octane rating number system enabled further work to be carried out on fuels for both aviation and vehicle engines which led to vast strides in fuel and engine performance in the 1930's and just before and during WW2.

Early Ricardo Engine Test rig
Early Ricardo Engine Test rig

Further developments in combustion chamber design for petrol engines led to a number of designs for companies such as Harley-Davidson, Triumph and Vauxhall, leading to a number of interesting designs. The 'Turbulent' combustion chamber was designed by Sir Harry in the winter of 1918-1919, and went on to be used by many manufacturers of air and water-cooled engines. Harley-Davidson used it in the engine of the VFD model.

1934 Harley-Davidson VFD Motorcycle
1934 Harley-Davidson VFD Motorcycle

One of Sir Harry's colleagues, Major Halford (who was to achieve fame in later years by his involvement in aero engines) was a motorcycle racing enthusiast, and after experiments with fuel mixtures in the major's Triumph 500cc motorcycle, a new cylinder head, cylinder and piston was designed and produced, enabling Halford to achieve greater success in his racing events. The result of this development was a contract from Triumph that used some of these features in a new machine, the Triumph-Ricardo motorcycle. The machine was a great success and is much sought-after by collectors.

Triumph-Ricardo Motorcycle
Triumph-Ricardo Motorcycle

Vauxhall Motors asked Sir Harry to design a luxury touring motorcycle following on from his work on the Vauxhall TT racing car. The motorcycle had a four-cylinder 960cc engine and shaft drive to the rear wheel. It was very advanced for the time and is another collector's machine, although very few were actually produced.

Vauxhall Motorcycle and TT Car
Vauxhall Motorcycle and TT Car

Record-breaking attempts enabled a lot of development work to be tried and tested, with resultant publicity for both the driver/pilot/owner and the engineer behind the original work, and Captain George Eyston was able to break the existing World Speed Record for Diesel Engined Vehicles at Bonneville Salt Flats, Utah, USA in 1936. The car achieved 159 mph using a special Rolls-Royce diesel engine which was designed by Sir Harry for Rolls-Royce. The car was called 'Flying Spray'.

R-R Ricardo Diesel Engine
Rolls-Royce Ricardo Diesel Engine

Aero engine design was one of Sir Harry's specialities and interests, and the sleeve valve was one of his 'babies' that he spent enormous amounts of time and money working on both single and double sleeve engines to try and get a reliable working engine arrangement. This was to become a major effort during the war years, and Bristol, in particular, was to achieve great success with its big radial aero engines. Rolls-Royce went down the in-line road with their own work, and the 'Crecy' was a major war effort engine that never reached production, despite having Govt backing. The engine was produced in both petrol and diesel versions, and despite achieving over 200bhp per litre was cancelled after the war end and as gas turbines became to be accepted as the future in aero propulsion. The Rolls-Royce Heritage Trust has an interesting book available on the Crecy, go to the link on the main menu for the Trust.

Rolls-Royce Crecy Sleeve-Valve Engine
Rolls-Royce Crecy Sleeve-Valve Engine

The Stirling engine is another project that the Ricardo company were involved in towards the end of the 1980's and after the death of Sir Harry. The US Govt commissioned the Company to participate in a project to develop a Stirling engine for passenger car use. While the resultant engine performed well and gave excellent emission performance, the operating requirements for road use compromised the design to the point where it was not a usable design.

Stirling Development Engine
Stirling Development Engine

Sir Harry also designed a car, he had designed almost everything else, so a car was a logical step. The Le Zèbre car was designed in 1923 and a picture of the vehicle is produced below. The engine is 2 litre capacity.

2 Litre Le Zèbre Car
2 Litre Le Zèbre Car

There are not many engine projects that Ricardo did not have a hand in, and more recent projects by the Company include work for various car makers and also original work on the Teledyne engine for the 1986 Voyager 'round the world' record breaking aircraft. Sir Harry was made a Fellow of the Royal Society in 1929, and was knighted in recognition of his services to the internal combustion engine industry in 1948. Sir Harry died in 1974 aged 89.


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