The Riley Imp Story

Several months ago I was sent a great deal of information about Riley Imps from David Evans of England.  This was a wonderful treasure trove above these cars.  What follows below is almost all information provided by David, who is obviously quite knowledgeable about these cars.

Riley is an iconic name in the history of the British motor industry. William Riley had started his bicycle manufacturing business in 1870 and by the early 1900s the company was experimenting with fitting petrol engines to its products. The subsequent move into motorised power was led by William’s three sons, Percy, Victor, and Allan. In 1905 Riley produced their first Tricar and in 1907 their first Riley four-wheeled production car. This was a light-car driven by a V Twin engine and was produced in various forms up to the beginning of WW1.

Riley Ulster Imp ADU303 driven by Beth Topliss at the Chateau Impney Hill Climb in July 2017

After WW1 Riley went on to produce cars with side valve engines and the next major step forward was in 1926 when the famous 1087cc four-cylinder Riley 9 model was introduced, this having a highly efficient design with overhead valves, hemispherical combustion chambers, and twin cam shafts located high in the block. Between 1926 and 1938 this model was produced in large numbers and became the bedrock of the company, in 1933 alone there were eleven different coachwork types in the Riley catalog including saloons, coupe’s and tourers. Although the Riley 9 could not be called revolutionary the exceptional attention to engineering detail and reliability set it apart and it became popular due to a recognition of it’s intrinsic quality.

The first entry into the sporting market by Riley was in 1927 when the Brooklands model was introduced, this being a lightweight sports car using a tuned version of the 9 engine. Riley sales value passed a million pounds in 1930 and the company survived the Great Depression remarkably well. The models produced at that time were successful in various forms of competition and thus established a strong sporting reputation for the marque. By 1933 the demand for sports cars had grown significantly and the next purely sporting Riley was introduced in 1934, it was to be called the Imp and this is where our story really begins.

Riley Ulster Imp ADU303 driven by James Topliss at the Chateau Impney Hill Climb in July 2015


The Standard Riley Imp

The standard Riley Imp was produced during 1934 and 1935 and the cars were assembled in the Competition Department at the Riley Works in Dunbar Avenue in Coventry. Total production was about 120. The Imp can be seen as a direct successor to the Brooklands but it was not until the Ulster Imp was announced was there to be a true completion car. The standard Imp was based on a Riley 9 and had the same mechanical specification but with a shortened wheelbase of 7 feet 6 inches and a lightweight occasional four seat open touring body. The engine was of 1087cc and had twin carburetors and a higher compression ratio than the standard production cars. This car was intended to have an extra “snappy” performance. The gearbox was described in the sales brochure as, “of a helical pattern giving four silent speeds”. The list price was quoted as £289.

Riley Ulster Imp ADU303 driven by Jim Evans at VSCC Prescott Hill Climb August 2009

A prototype competition Imp had been displayed at the 1933 Motor Show, but the first four production cars were radically different to it especially in the chassis design, this being a boxed channel with riveted tubular cross-members and so was far more rigid. This prototype plus the first four production cars were entered in the extremely demanding 1934 RSAC Scottish Rally that involved a 1000 miles of high speed touring from three starting points, Harrogate, Edinburgh and Glasgow and concluding with acceleration and braking rests. The Imps finished 1st, 4th, 6th, 7th and 10th in class, and won both the Team and the Ladies prizes, the latter having been won by Dorothy Champney and Kay Petre in the prototype competition Imp AYK597. These two intrepid ladies went on to finish 13th overall in the 1934 Le Mans 24hr race in the same car. The publicity gained from such great success in two very different types of very demanding competitive events significantly enhanced the sporting reputation of the marque.

The Riley Ulster Imp

The term Ulster Imp is generally associated with the competition versions that have a boat-tailed body, but AYK597 was still in almost standard trim. Two other two Imp’s were also entered at Le Mans that year and were described as “special bodied Imps” and when several more of this model were produced for the Ards TT in the September, then the name Ulster Imp was adopted.

Alan Lomas With His Very Original Standard Riley Imp AKV216 At The Hampton Court Palace Concourse D’Elegance In August 2017 

The chassis of the Ulster follows that of the standard Imp, but with two main differences. The fuel tank is large and oval and is mounted on a cradle on an additional rear cross member and is held in place by two large spring-steel straps and the other and more significant difference is the mounting of the front springs.

Riley Imp Engine In Car AKV216

The mechanical changes on the Ulster Imp are extensive. The engine is more rigidly mounted and the engine block has seven webs to strengthen the rear main bearing. The racing crank-shaft is fully machined and carries detachable balance weights with larger front, rear, and big-end bearings. Oil is supplied from a finned 14 pint electron alloy sump by a triple plunger pump. The compression ratio was set at eight and a half to one to meet the fuel regulations for the 1934 Ards TT. The camshafts, rockers, and timing sequence are all to a special specification and there is a BTH magneto below which sits a water pump. Induction is by two 30mm SU carburetors. Drive to the 19 inch wheels is through a centrifugal clutch to an ENV type 75 gear-box with its own special deep sump. The propeller shaft is supported in a torque tube and the rear axle nose-piece is made of electron alloy.

Rear semi-elliptic springs have nine leaves and are under-slung on electron alloy spacers thus lowering the rear of the car by just over two inches. The front springs have seven leaves and the Ulster has forged,­ rather than rolled, eyes. Haford shock-absorbers are used front and rear. The continuous cable braking system is common to both models but the Ulster has roller bearings in all the cable pulleys and there is other strengthening to the system. Steering is by worm and segment set in an electron steering box.

Standing beside the very famous ex-5th Earl Howe ERA R8C is the current 7th Earl Howe and next to him is Dave Evans with his Riley Ulster Imp ADU303, (The connection being that the ERA (English Racing Automobiles) were developed from Riley competition components) 

A 17 inch steering wheel is fitted and with levers in the boss to give both timing and throttle adjustment however ADU303 is currently fitted with a Scintilla magneto with automatic advance and retard so the lever for this function is currently redundant. Instrumentation consists of a large 6,000rpm rev-counter, ammeter, temperature, oil and fuel pressure gauges. Fuel is pressure fed by a hand pump. A Rotax panel provides magneto on-off, lighting, and starter controls, all as fitted to the Brooklands.

The body of the Ulster differs greatly from the standard Imp being a single alloy skinned tub onto a steamed slim ash frame and the rear tail section is detachable. The Ulster is considerably lighter than the standard model being 14.5 hundredweight compared to the standard 17 hundredweight. To comply with the regulations for the 1934 Ards TT a full fold-flat windscreen was fitted but at the start of the race it was folded forward and two small aero screens were slotted into the lower part of the screen frame. An under tray was fitted from the bulkhead to the tail, and the bonnet had an offset hinge to allow generous access to the engine from the offside and was secured by two leather straps.

World Drivers Champion Mike Hawthorn at the wheel of his first competition car, Riley Ulster Imp KV9475

A total of sixteen Ulster Imps were manufactured by the Riley Competition Department of which nine still survive. The advertised sale price was £450.

Five of the nine surviving Riley Ulster Imps at the 75th anniversary meeting of the introduction of the model in 1934, L to R, AVR718, ADU302, ADU303, KV9475, and ADU162

Those who have Riley Imps form a tightly knit community.  The current ownership of these cars is shown below.

Current Ulster Imp Ownership

Registration Chassis
Number Number Owner Comments
KV 8025 6024449 Dismanteld by works pre-war
KV 8026 6024450 Dismanteld by works pre-war
AYK597 6024755 Roland D’leteren
KV 8932 6024757 Nothing is known Probably dismantled pre-war
KV 8933 6024758 Destroyed in fire 1939
KV 9475 6024867 David Ely
KV 9476 6024868 Frank Hawke
KV 8990 6024870 Nothing is known Probably dismantled pre-war
Unknown 6024981 Nothing is known Probably dismantled pre-war
Australia 6024990 Ian Ruffley Supercharged 12/4 engine
ADU 162 6024992 Diane Weeks
ADU 300 6025034 Dismanted by works in 1935
ADU 301 6025035 Christian Meier Germany
ADU 302 6025038 Jim Cartwright
ADU 303 6025036 Dave Evans
AVR 718 6025037 Dan Geoghegan and Bob Meijer

If you have any questions or comments about this post or the Riley Imp cars, then leave a comment below or you can send me a private email message at the following address: shanna12 at comcast dot net

This entry was posted in Uncategorized and tagged , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s