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 distribution, valve temperature, and the effect of dual ignition on a Hispano engine.
| Identifier | Morton\M4.1\ img039 | |
| Date | 11th March 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 4214 9770 REF: HS{Lord Ernest Hives - Chair}/ACL/HIV/ER DISTRIBUTION: Good - with slight tendency for central cylinders to richen as speed increases. Valve temperature appears equal to that of EAC. No stretch of valves occurred during the tests. Valves leave their seats at 2800 to 3000 R.P.M. EFFECT OF DUAL IGNITION ON HISPANO. The two plugs are located facing each other at the opposite sides of the combustion chamber. The distributors are so arranged that they cause a spark to occur simultaneously at each plug. With one plug only, audible detonation takes place up to approx. 1000 R.P.M. full load but does not occur when using both plugs. PISTON From attached curves it is seen that greater advance is required when using one ignition only. Although no audible detonation takes place above 1000 R.P.M. with one plug its presence is clearly shown on the indicator diagram but by using two plugs this is entirely eliminated. | ||