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).
Disadvantages of high compression ratios, such as detonation and vibration, and proposing double battery ignition.
| Identifier | ExFiles\Box 19\7\ Scan078 | |
| Date | 10th March 1924 | |
| To E.{Mr Elliott - Chief Engineer} from R.{Sir Henry Royce} To HS.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} PN.{Mr Northey} BY.{R.W. Bailey - Chief Engineer} *790 S E C R E T. R3/M10.3.24. E.A.C. 2.3.5 & 5. X.790 X.9550 X.9780 High compression ratios and compression pressure have two diadvantages :- (a) Detonations. (b) Vibrations. Supposing we can get over (a) would (b) put us down below 4.5 - If not, we must get over (a). Our EAC. engine should be compared with others, (as well as Hispano) including the Hawk. In the case of the ignition we have no time to alter extensively at the moment, and if the engine runs as well with one ignition as with two, and supposing the un-used plugs do not get dirty can we not fit a switch to stop the ungoverned magneto always, unless definitely desired (because of failure or for test). I am proposing we use double battery ignition, and a magneto like Goshawk which would be standing until wanted, but I fear we cannot do this at the moment. Can E.{Mr Elliott - Chief Engineer} make a scheme of a better position for the second plug to get definite advantage of double ignition. I should propose this be between the tappets if it is possible. R.{Sir Henry Royce} | ||