From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
17,000-mile test report in France for a 6.B.IV.Bentley, focusing on engine performance.
| Identifier | ExFiles\Box 83\1\ scan0240 | |
| Date | 10th October 1936 | |
| R 20ad Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/I/JAB.10.10.36 Noted by R H Lin Tester Hs{Lord Ernest Hives - Chair}/5/m To. Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}/IMW.{Ivan M. Waller - Head of Chateauroux} c.c. Wor.{Arthur Wormald - General Works Manager} (Strikethrough) c.c. E.{Mr Elliott - Chief Engineer} c.c. By.{R.W. Bailey - Chief Engineer} c.c. Da.{Bernard Day - Chassis Design} c.c. EP.{G. Eric Platford - Chief Quality Engineer} (Strikethrough) c.c. Mx.{John H Maddocks - Chief Proving Officer} c.c. Cx.{Major Len W. Cox - Advertising Manager} c.c. RHC.{R. H. Coverley - Production Engineer} c.c. Hs.{Lord Ernest Hives - Chair} SPECIFICATION OF 6.B.IV.BENTLEY. To. RHC{R. H. Coverley - Production Engineer}/CP. 20.4.36 & 2.5.36 RHC{R. H. Coverley - Production Engineer}/WSC.{W. S. Cassel} 4-5-& 6.8.36 RHC{R. H. Coverley - Production Engineer}/RC.{R. Childs} 6.8.36 17,000 MILES TEST REPORT IN FRANCE. Including 3,284 Miles Continental Touring by E.{Mr Elliott - Chief Engineer} ENGINE UNIT B.22. Apart from the bearing trouble referred to under separate headings, this has been a most satisfactory unit. Idling has been above standard throughout. The flexible engine mounting, new exhaust system and dashboard insulation, have provided a degree of smoothness and silence superior to previous Bentley standards but the tappets were somewhat noisy throughout. Starting was very good at all times both when hot and cold. Power and acceleration were normal and were maintained throughout the mileage. It was observed that no advantage was gained by going beyond 3,800 rpm. in third gear, performance being better in top beyond this speed. This point should be emphasised to avoid futile reving of the engine. The maximum speed was approximately 90 MPH. at which the rev-counter showed 4,500 rpm. From 10 MPH. in top gear, 4,000 rpm. could be attained in 40 seconds, and as the car is exception-ally easy to drive right up to its maximum speed, it follows that it is very easily over-driven. It is to this fact that we attribute the bearing troubles experienced. We are paying the price of catering to the very real demand for an abnormal top gear acceleration at lower speeds. Unless more reliable bearings can be provided, engine speeds will need to be reduced. The engine was free from detonation using "Azur" petrol. Varying degrees of detonation were experienced with "Esso" and with ordinary "Tourisme", the engine was almost unusable. There were no misfires and the pick-up was smooth. Pulling hard in top gear between 30 and 40 MPH. the engine was particularly smooth and steady. | ||