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).
Crankshaft road tests and material comparisons for chassis, aero, Merlin, and Exe engines.
Identifier | ExFiles\Box 132\1\ scan0042 | |
Date | 7th April 1938 | |
- 2 - HPS.{Horace Percy Smith - Experimental Factory Mgr}1/VS.{J. Vickers}7.4.38. B.24 Unit. - Crankshaft Ex.27885. 15,000 miles road test - not examined. As will be seen from the above figures, most of our experience with Hykro crankshafts has been gained in connection with chassis units, and a good deal of bench and road testing has been carried out with satisfactory results but only in conjunction with Whitemetal and Hall's Metal bearings. The longest individual running time for any aero shaft is 106 hours, after which the shaft in question was rejected on account of the poor condition of pins and journals; this, however, is attributed to a thin outer layer of unstable material on the nitrided surfaces not being completely removed in lapping finally to size. The other two Hykro crankshafts in Merlin and Exe engines respectively were both satisfactory when last examined, but a total of approximately 200 hours general development running does not constitute sufficient experience upon which to draw a conclusive comparison, and at this stage it can only be said there is no definite evidence of improvement in condition due to the higher surface Brinell of this material as compared with V.C.M. HPS.{Horace Percy Smith - Experimental Factory Mgr} | ||