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).
Engine breathing, valve timing, and potential efficiency gains without deteriorating quality.
| Identifier | ExFiles\Box 133\1\ scan0205 | |
| Date | 13th May 1937 | |
| -6- worth the quality loss which would of necessity accompany it in the way of increased bearing and piston clearances, lower ring pressures, fewer bearings etc. A point which, however, would repay attention and which is receiving a considerable amount is the loss accounted for in breathing. As has been remarked before, the breathing system has been cleaned out considerably, but as, due to mechanical limitations, larger valves are more or less ruled out, and for power reasons the valve timing cannot be altered to any appreciable extent, it would appear that we are more or less limited in this direction to ensuring a free flow of air through passages as short as possible, both into and out of the cylinder. An incidental point in this is that the exhaust port might repay a little more attention. Taking it on the whole, however, it is very difficult to make any recommendations which will give a really appreciable power gain and whilst a little might be gained here and there, the units can be said to be just about as efficient as is possible without deterioration of quality. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} | ||