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 and arrangement of exhaust rockers for a new engine.
| Identifier | ExFiles\Box 43\3\ Scan104 | |
| Date | 1st January 1927 | |
| 4003 To E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} RL/M1.1.27. c. to BJ. Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} RR & F.10. EXHAUST ROCKERS. X.3822 E.4011 X.4003 It looks to me as if the inlet rocker shaft should be the same distance from the valves and the camshaft as the exhaust, or the exhaust reduced to inlet dimensions. This would get over many difficulties, or would it be any advantage if the inlet valve springs were 1.4" and the exhaust double and 1.3" dia., or both double 1.3" dia. It is also possible to cut the boss of the inlet rocker to clear the spring. I make it that this boss should come ¼" beyond the centre of the spring. The bush would have wide collar, thus - SEE ORIGINAL FOR SKETCH. Your bosses are under 1"; mine would be 1¼", and in a better position, for the double reason of cam pressure and thrust. No special features on cap needed. This memo. seems valuable because it makes these parts better and cleaner, and simpler than previous schemes and very definitely better than the original double arrangement. It seems possible to have rollers if found better, or RG.{Mr Rowledge} suggested solid rollerless rockers, or Mercedes pattern pin-less roller. As in my previous memo. I suggest two rockers, only one right hand, and one left hand, throughout the engine, if the two rocker shafts can be made equal. This scheme seems so good: it is the best we know for the new RR.25. or whatever our 6" X 7" Vee engine is to be called. It seems good to keep the exhaust valves further apart than the inlet, to allow of water cooling. If so this is probably the best scheme we shall find in the time available for the 6" X 7". (long 2) R.{Sir Henry Royce} | ||