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).
8-cylinder engine design, comparing Cadillac La Salle crankshaft dimensions and American crankcase stiffness with Bentley components.
| Identifier | ExFiles\Box 178\2\ img185 | |
| Date | 19th February 1934 | |
| -6- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}9/KW.19.2.34. Whatever the merits of their theory, the front end of the 320 cu. inch frame with a cross in it and without a bumper stabiliser is the steadiest I have seen for a long time. This confirms we should try the Chrysler mounting. LINE 8 CYL. ENGINE DESIGN. I have concentrated on finding out what I can about this. Details of the new Cadillac La{L. A. Archer} Salle straight eight crankshaft are - Main Journals Dia. Length Front 2.250 1.625 Front Inter 2.437 1.250 Centre 2.500 1.375 Rear Inter 2.562 1.250 Rear 2.625 1.562 Crank Pins 2.250 1.375 This stepping up of the journal dia. towards the flywheel I consider entirely logical. You will remember that we have repeatedly tried to do this on the Bentley flywheel bearing but have been frustrated by the oil flinger. I consider that we should make another attempt and at least try it on the road, even if we have to run without an oil flinger for the test. I am also encouraged that shortening of the pins enables one to step up the journal dia. again (and we might do it progressively as on the Cadillac) and so get a much stiffer shaft; also that Lincolns and Cadillacs are using a 1" wide big end with a steel rod, therefore on the Bentley shaft we should complete our test running the alum. rods with lead bronze strip bearings and 1.00" wide big ends. CRANKCASES. It is noticeable how very stiff the back wall of the American crankcase is, and how generous is the cap (usually secured by four bolts) that covers the flywheel bearing. (This and the crankshaft data indicates that the Americans have had our trouble of flywheel flutter). One would like to see something of the sort incorporated on the 20/25 and Bentley. | ||