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).
Cold starting tests performed on a Bentley chassis.
| Identifier | ExFiles\Box 62\1\ scan0215 | |
| Date | 25th November 1933 | |
| x6027 Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Wst. c. to R.{Sir Henry Royce} c. to Ry. c. to Wor.{Arthur Wormald - General Works Manager} c. to Rn.{Mr Robinson} c. to EF. Hs{Lord Ernest Hives - Chair}/Wst.6/MA. 25.11.33. COLD STARTING TESTS ON BENTLEY CHASSIS. We took Experimental chassis Z.R.IV. to Messrs Lucas, Birmingham, on Thursday night in order to place the car in their refrigerator for cold starting tests on the following morning. On Friday morning the temperature was -2°C. which was approximately also the temperature of the engine oil. The equipment on the car electrically was entirely representative of standard with the exception of the battery, which was an eleven plate battery instead of the standard nine plate, i.e. the plates were thinner giving a better starting performance. The engine modification from standard consisted of the fitting of Aerolite pistons. Mobiloil Grade D.{John DeLooze - Company Secretary} oil was used. The engine turned over very slowly, about 40 R.P.M. but eventually a start was effected. It was found helpful to short circuit the ballast resistance on the ignition to help the ignition in this extreme starting condition, but this is not a policy to be recommended. The reason we shorted the ballast was because the volt drop between the battery and the motor reduced the voltage applied to the coil, the supply for the coil being tapped off from the starter switch instead of direct from the battery in order to save length of cable etc. We have previously decided to try and get in a larger gauge of starter cable, and also tap the ignition direct from the battery instead of through the starter switch, this will considerably help the ignition under extreme starting conditions. | ||