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).
Valve lift diagram formulas and proposing different extra clearance amounts for car versus aero engines.
| Identifier | ExFiles\Box 23\5\ Scan049 | |
| Date | 17th January 1928 | |
| E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to BJ. Wor.{Arthur Wormald - General Works Manager} X4336 R6/M17.1.28. X.4214 X.3616 X.4336 X.8060 VALVE LIFT DIAGRAMS FORMULA. The results from the latest Condor valve lift suggest that we should not depart from our standard practice and quantities, but that we ought to try adding a quick extra clearance part - Hispano, Stutz etc. - to the present foot of about .010" to .020" for aero engine practice, but I fear it would not do for our car practice because of noise, but it could be tried in the smaller amount: therefore add :- extra clearance &toe rapid of .010" for car and .020" for aero, when next we are designing valve lift cams. Diagram text: SAFETY CLEARANCE SILENT PERIOD R.{Sir Henry Royce} WORKING CLEARANCE | ||