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).
The design and specifications for the Bentley 50 crankcase and crankshaft.
| Identifier | ExFiles\Box 132\3\ scan0092 | |
| Date | 10th March 1938 | |
| BT{Capt. J. S. Burt - Engineer}/NS.{Norman Scott} c. Rm.{William Robotham - Chief Engineer} c. Da{Bernard Day - Chassis Design}/IND. c. Da{Bernard Day - Chassis Design}/Jnr.{Charles L. Jenner} 816. DA.{Bernard Day - Chassis Design}10/G.10.3.38. BENTLEY 50 - CRANKCASE & CRANKSHAFT. Please receive herewith :- E.CD.436 Top Half Crankcase, Crankshaft etc. Bentley 50. This design is for use in conjunction with those made by the project office, for the engine with overhead inlet and side exhaust valves. The crankcase and cylinders are in cast iron monobloc construction with the main oil gallery as part of the casting, the main bearing caps are also in cast iron. The crankshaft is similar to Wraith lll with "Packard" type balance weights, as shown on E.CD.412, with modified front and rear ends, and the crankshaft thrust has been transferred from the rear bearing to the centre. The connecting rod and piston for this engine are the same as used for the Bentley lll engine. The thickness of cylinder barrels is as fixed up by Project, and in order to obtain a reasonable thickness for core sand between the barrels, we have asked for the barrels to be flatted between cylinders 1 and 2, 2 and 3, 4 and 5, and 5 and 6. It should be possible to commence the detail of the crankcase from this design, and we shall be sending further particulars of crankcase almost immediately. DA.{Bernard Day - Chassis Design} | ||