Cummins railton takes on the Kop Hill Climb

18 September 2015 – FIVE years in the making, the Cummins-Railton is now ready to race, with its first outing the infamous Kop Hill Climb.

The 1936 6.7ltr Cummins-Railton was designed and created by engineer Terry Clarke and is an exact replica of the famous Napier Railton Special racing car.  The car is not only dimensionally accurate, but features a high pressure charged commercial diesel engine, in place of the original Napier Aero engine, which is no-longer available.

The Cummins 6.7ltr diesel engine installed in the car has been developed by Clarke and Cummins engineers to give the same power as the Napier’s original 24 litre.  The engine also has a similar weight, to replicate the speed and performance of the historic car as accurately as possible.

Now ready for its first public-run, the Cummins-Railton, will take on the infamous Kop Hill Climb at Princes Risborough, Buckinghamshire on 19th and 20th September, joining a line-up of more than 400 historic cars and motorcycles taking on the famous hill.  

Restorer Terry Clarke believes the car is more than up for the challenge:  “Kop hill is the perfect setting to show fans what the car can do and we can’t wait to take on the hill.  The original Napier Railton is now limited to 1,800 rpm, so the replica offers fans a unique chance to appreciate the power and speed of the original, and we believe they will be impressed by its performance.”

The original car was first raced in August 1933 by John Cobb, and broke the Brooklands outer circuit lap record of 143.44mph in 1935.  It set the 24 hour record of 150.6mph at the Bonneville Salt Flats in 1936.  Now based in the Brooklands Museum (Surrey, UK), the car is powered by a Napier Lion XI gasoline aero engine, with 12 cylinders in three banks of four arranged in a ‘W’ configuration.  It has a displacement of 24 litres with a rated power of 530 hp at 2,350 rpm.  

Clarke said: “Having access to the original Napier at Brookland Museum, was key to making sure our car was built as a dimensionally-accurate replica, using the same Gurney Nutting construction features as found on the original.”

The replica is powered by a Cummins’ ISBe, an in-line 6 cylinder, 6.7 litre engine.  Designed and built in the UK, it is normally available for up to 310 hp commercial applications with tough duty cycles such as double deck city buses, rigid trucks and military vehicles.  To push the engine power capability, a number of high specification components have been added including the block, cylinder head, camshaft, pistons, fuel injectors and turbocharger.

Steve Nendick, Cummins Communications Director said this has been no-mean feat for the engineers who have been working with Clarke from the outset.  “This project is an excellent opportunity for Cummins to promote diesel power in areas outside our usual sectors. Enabling us to highlight the key product developments that have made our modern diesel engines into an efficient and ultra clean form of power.”

Clarke and the Cummins team used the latest components, coupled with engine development and electronic controls expertise as well as some minor configuration changes to increase power,  achieving close to 500 hp.

Nendick added: “Although this is not destined for full production, it highlights the capabilities of our diesel engines and engineers to push the envelope in challenging projects - we can’t wait to see it in action.”

Cummins has a strong history in racing, using it to test product durability as far back as the 1930s.  In fact, the 1931 No. 8 Duesenberg Indianapolis 500 car, built around the same time as the Railton, was also driven at Brooklands during a European tour organised by the company founder Clessie Cummins.  This car still runs and is displayed in the Indianapolis Motor Speedway Museum.

About the Kop Hill Climb

The annual Kop Hill Climb sees 400 historic cars and motorcycles taking on the famous hill, and many more displaying in the Paddock.  Vehicles range in age from the early 1900’s to modern day exotics, with 15,000 visitors attending over the two days, raising money for a wealth of charities.  See for more information.

About Cummins

Cummins, a global power leader, is a corporation of complementary business units that design, manufacture, distribute and service diesel and natural gas engines and related technologies, including fuel systems, controls, air handling, filtration, emission solutions and electrical power generation systems.

Headquartered in Columbus, Indiana, (USA) Cummins currently employs approximately 54,600 people worldwide and serves customers in approximately 190 countries and territories through a network of approximately 600 company-owned and independent distributor locations and approximately 7,200 dealer locations. Cummins earned $1.65 billion on sales of $19.2 billion in 2014.  In the UK Cummins employs over 5,000 people and manufactures engines, components and power generation solutions.  More information can be found on  Follow us @cumminseurope.


Steven Nendick
Cummins Ltd, Darlington, UK
Tel:  +44 (0)1325 556717

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