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).
Summary of results from a 15,000-mile test on a Bentley 6.B.IV car, detailing the performance of special features.
| Identifier | ExFiles\Box 83\2\ scan0295 | |
| Date | 13th March 1938 | |
| To Sg.{Arthur F. Sidgreaves - MD} G.Hs.{Lord Ernest Hives - Chair} C.By. G.Ds. C.Rm.{William Robotham - Chief Engineer} G.Mk. G.GnH. G.HPS.{Horace Percy Smith - Experimental Factory Mgr} 200 CHATEAUROUX 1/.13.3.38. 6.B.IV - BENTLEY. 15,000 MILES TEST CAR. Summary of Results of Test of Special Features described in List Circulated on 8.12.37. The car covered 10,561 miles in France. The mileage given after each feature includes the preliminary running in England. The car has returned to England for further running and final proving of experimental features by Mx.{John H Maddocks - Chief Proving Officer} --------------------------------------------- Parts. Result of Test. Centricast A.C.6 Main and big end bearings. 13,268 miles. No trouble experienced and not disturbed during mileage. Condition not considered satisfactory for standardisation after examination. Hykro crankshaft. 19,320 miles. Satisfactory, subject to strip report. Silent Camshaft EB.3240 13,268 miles. This quietened considerably a valve gear which was particularly noisy before it was fitted and the standard of quietness was maintained throughout. The tappet adjustment necessary during the mileage was negligible. Oil Filler LOP EB.153 LeC.4460 with crankcase breather in place of rocker cover breather. 19,320 miles. Satisfactory in all respects. Recommended for production in line with present standard 25/30 practice. Deturbulated Cylinder Head with increased inlet ports and 7 : 1 comp. ratio. Discarded on account of detonation and material situation. French mileage running on standard deturbulated cylinder head. | ||