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).
Progress memo on the development of an overhead inlet side valve exhaust unit, detailing issues and findings.
| Identifier | ExFiles\Box 134\2\ scan0104 | |
| Date | 16th February 1937 | |
| 1129. Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Hs.{Lord Ernest Hives - Chair} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} OVERHEAD INLET SIDE VALVE EXHAUST UNIT. Since Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}25/KW.1.9.36. work has been continuing on this unit. Taking the four faults enumerated in the previous memo:- (a) Cylinder distortion. On our first endurance run we did experience a certain amount of distortion which caused gumming of the piston rings on the exhaust valve side. Jet control of the water, however, eliminated the trouble, and we have run 100 endurance hours perfectly satisfactory at 4,000 revs., the equivalent of a main engine horse-power of about 150. (b) Width of Unit. The fact that the unit is wider than the conventional job we believe to be more than compensated for by the improved Foundry proposition that this unit represents. (c) Aluminium Cyl. Block Construction. At the moment we think this engine should be considered as a cast iron cylinder block and crankcase unit construction. The dry liner alum. block is not out of the question. (d) Limitations of Valve Gear. Even with the big inlet valves we are using the valve gear does not seem to limit the speed at which the engine runs. We have had some difficulty in making the single cylinder unit repeat its original power output, but in no case has it given less power than the standard Bentley single cylinder unit. The attached curves shew the latest figures obtained. We are of the opinion that the maximum power output of this unit is, in any case, of secondary importance; its primary virtues appear to us to be:- continued | ||