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).
Design for 'dieselising' the S/C unit, including the cylinder head and piston arrangement.
| Identifier | ExFiles\Box 134\1\ scan0160 | |
| Date | 16th May 1939 | |
| 1129 To By/Ald.{F. Allwood - Experimental Design} Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}8/JH.16.5.39. DIESELISING THE S/C UNIT. We hand you herewith a cylinder head and piston arrangement designed for a two stroke engine. We should be glad if you would scheme out and instruct a similar combustion chamber arrangement adapted to the new 3.500" bore Bentley cylinder block. We do not know the best position for the hollow in the piston, but suggest you detail three pistons, with the piston recess opposite (a) inlet valve (b) exhaust valve (c) divided between the two valves. In so far as is possible the design sketched should be followed, but we suggest that a diversion be made in respect to the inlet valve. This, on the sketch, is shown recessed and we should like you to bring this flush fitting for an initial try-out. Provision should however be made to enable the valve to be recessed later, and to compensate for the reduced compression ratio, we suggest a larger valve head be designed. Two injector positions will be necessary for the alternative piston designs, and if possible a third could be incorporated. This will, of course, depend on the final layout of the design. The gudgeon pin should be left as at present, but to insure against possible failure in this respect, we should like a 30% larger pin designing, and a new connecting rod. Sufficient metal should be left on the piston bosses so that these may be machined out oversize if required. Any other details which may arise should be discussed with Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} With regard to injector equipment, we recommend that the pump scheme be as laid out by Da{Bernard Day - Chassis Design}/AM. The nozzle holder should be decided upon and ordered so this will give us a much better idea of how to fit this in to the best advantage. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} | ||