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).
Advantages and feasibility of using dual ignition in 'India engines'.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan015 | |
| Date | 7th March 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LG7.3.28. INDIA ENGINES - DUAL & SINGLE IGNITIONS X5680 Referring to memo. E1/M25.2.28 on the subject of India engines, we note the remarks regarding the question of the number of spark plugs per cyl. and understand there is a possibility of providing plugs on the exhaust side which would enable us to take advantage of dual ignition. While we are fully aware of the advantages and desirability of igniting the charge from two distant points on large cylinders, as gathered from our experience with the standard and turbulent type Phantom cyl. heads, we admit the case is somewhat altered when considering the smaller cyls. of the 20 HP. and probably there is not such a strong demand for the extra complication of dual ignition. At the same time we think it worth while considering the advantage we may hope to obtain on the India engine by incorporating two opposed spark plugs in the new design, and therefore make reference to tests carried out on the Lorraine Dietrich engine which has approximately the same bore as the 20 HP. RR. and is provided with two opposed plugs per cylinder. The Lorraine engine we tested had a bore X stroke = 2.95" X 5.12" and the ignition was provided by the dual Delco coil system with the usual automatic advance. Two spark plugs were used, one on each side of the engine mx{John H Maddocks - Chief Proving Officer} and the time of ignition was synchronised. The synchronisation was not electrical but relied upon the setting of the contact makers in the same contd :- | ||