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).
Specification document detailing design instructions for a new 6-cylinder aluminium B.60 engine.
| Identifier | ExFiles\Box 175\2\ img092 | |
| Date | 15th March 1941 | |
| Ev.{Ivan Evernden - coachwork} and Jnr.{Charles L. Jenner} from Rm.{William Robotham - Chief Engineer} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Em/Dt. C. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} Winch 2006 Em.7/H.18.15.3.41. SPECIFICATION OF ALUMINIUM B.60. ENGINE. We are about to instruct an 6-cylinder aluminium engine. This engine will be described as the R.A.F. winch unit, as it will form an alternative to the P.lll. engine at present specified. All drawings should be marked accordingly. There are a number of experimental features which we should like incorporating in this specification, some of which require design work. Dealing first with designs required :- 1. CYLINDER HEAD. When the intermediate head proved unsatisfactory, we decided that, to get the best results out of the high power engines, each bore would have to have its own combustion chamber, which will be made to give the best possible proportions, though the inlet valve and sparking plug positions would remain unaltered. This disposes of the original question of having one cylinder head casting and make it suitable for all the smaller bore engines by machining off the gasket face of the head. For the aluminium engine, we therefore require a combustion chamber design for a 3 1/4" bore. 2. CRANKSHAFT LIGHTENING. The crankshaft was put up from 3 1/4" to 3 1/2" journals to improve bearing life, and not to increase the crankshaft strength. We therefore consider that we should increase the size of the hole through the journals to bring the crankshaft strength back to where it was with the 3 1/4" main bearings. 3. CONNECTING RODS. The Senior Range rods really require re-designing, since they are unnecessarily heavy. This has come about through fitting bearings with a wall thickness of .078" into a conn. rod which was designed for a thickness of .125". - Continued - | ||