Bentley 4 Litre 1931-1934
The Bentley 4 Litre was a motor car built on rolling chassis made by Bentley Motors Limited.
| Production | 1931 50 produced |
|---|---|
| Assembly | Cricklewood, London |
| Designer | Walter Owen Bentley, Harry Ricardo |
| Body and chassis | |
| Class | Luxury car |
| Body style | as arranged with coachbuilder by customer |
| Chassis | Pressed steel parallel girder with large diameter tubular crossmembers, semi-elliptic springs front and rear. |
| Layout | FR layout |
| Powertrain | |
| Engine | 3.9 L Ricardo IOE I6 6 cylinder, in-line conformation, cast iron cylinder block, bore and stroke 85 x 115mm. engine capacity 3,915 cc |
| Performance | Max. speed 83 mph (134 km/h) |
| Transmission | ingle dry plate type clutch, 4 speed gearbox |
| Dimensions | |
| Wheelbase | 134 in (3,400 mm) 140 in (3,600 mm) |
| Chronology | |
| Predecessor | 6½ Litre & Speed Six |
| Successor | 3½ Litre |
The 4 litre chassis was conceived and built in a failed attempt to restore Bentley to a good financial state. Announced 15 May 1931, it used a modified four litre Ricardo IOE engine in a shortened 8 litre chassis at two-thirds of the price of the 8 Litre in an attempt to compete with the Rolls-Royce 20/25. Instead, Bentley went into receivership shortly afterward, from which it was purchased by Rolls-Royce Limited.
The conventional straight-6 engine used an 85 mm (3.3 in) bore and a 115 mm (4.5 in) stroke for a total displacement of 3.9 L (3,915 cc (238.9 cu in)) and a power output of 120 bhp (89 kW) at 4,000 rpm. The engine power was not suitable for the heavy chassis.
In a last-minute act of panic, when rational reflection might have advised the board to call in the receiver, Bentley's directors decided to fight on with a new model for shares in a new area of the market.
Disastrously, Bentley aimed the new model in direct competition with the Rolls-Royce 20/25. Bentley himself had viewed these plans sceptically. His advice, that the 4 Litre Bentley in respect of acceleration and top speed would not live up to the expectations of the Bentley clientele, was ignored.
He had no influence on the concept, because the 4 Litre Bentley was derived from the chassis of the 8 Litre Bentley with an engine designed by Harry Ricardo.
Observed from a distance of over 60 years, and without the jaundiced view of the Bentley's purists, who still share Bentley's opinion completely, the outcome of this combination of chassis and engine should be judged as competent, one which could justifiably be considered as in the same class as the 20/25 but offering superior power.
The engine's design broke with everything that had been typical for Bentley up to then. The inlet valves were arranged in a detachable cylinder head, the exhaust valves in the cylinder block. Crankcase and oil sump were made from the magnesium alloy, Elektron.The massively dimensioned crankshaft ran in seven main bearings. At 4,000 rpm the engine delivered 120 bhp.
With the exception of small details the chassis was identical in design with that of the 8 Litre Bentley. In fact all those chassis already produced for the 8 Litre - now no longer needed because of the depressed market - were modified for use in the 4 Litre models, so saving much needed cash.
For the small car the frames were shortened to wheelbases of 134 inches or 140 inches.
A novelty was the centralised chassis lubrication from Tecalemit which was operated by a foot pump. This limited the work of greasing to the lubrication points at the propeller shaft and the front axle.
The first 4 Litre Bentley was registered in May 1931. Up to the collapse of the company, exactly 50 cars were finished, 39 of these of short wheelbase, the other 11 of long wheelbase.Customers did not queue for this car.
The finished chassis were taken over with all the other Bentley assets by Rolls-Royce, but sold in one batch to Jack Barclay, the leading London dealer. He managed to sell them one by one. The last 4 Litre Bentley was not registered until June 1933.