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).
The performance and failures of an ignition distributor and sparking plugs during testing.
| Identifier | ExFiles\Box 82\5\ scan0156 | |
| Date | 2nd June 1937 guessed | |
| ( 5 ) received from Works. This was again replaced by a new Wraith type fan which ran the last 3,500 miles. No trouble experienced with any of these fans. IGNITION DISTRIBUTOR. Delco-Remy Distributor. Chevrolet Suction Ignition Control fitted during last 13,000 miles. The retaining clip on one of the contact breaker arms pivot pins came off during the running after 13,000 miles, due to wear of the groove in which it fits. The fibre block broke off one contact breaker arm at 14,734 miles. With the suction ignition control fitted, the ignition was permanently set 4° B.T.D.C., the normal full advance position with the Delco unit. The hand control was deleted. The suction control further advanced the ignition, beyond the normal full advance setting, on light throttle opening, i.e. when the inlet pipe depression was light, and the demands on the engine slight. Its object was to improve the petrol consumption at low average speeds, and under gentle driving conditions. No improvement was noted or expected under the running conditions of these tests. The presence of the device could not be detected by the driver and it gave no trouble. At no time was the absence of the hand control felt, and with the Delco-Remy governor, it is quite unnecessary with the petrol used, i.e. Esso Ethyl. SPARKING PLUGS. K.L.G. FLB.50.X. The gaps increased from .020" to .028" during the first 2,320 miles running and were re-set .020" a further increase from .020" to .040" occurred in 7,100 miles. The plugs were returned to Derby for inspection as the points had burnt very thin, the total distance run being 9,420 miles. | ||