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).
Technical note discussing engine cold starting performance, comparing different car models, fuel types, and carburetter pilot jets.
| Identifier | ExFiles\Box 74\2\ scan0059 | |
| Date | 16th December 1921 | |
| Contd. -2- Hsl/LG16.12.21. ---------- car is left out all night in a frost so that the starter will only creep the engine over in the morning, the operation of the primer is an assistance. We find that 4.EX Car which is fitted with the Bijur Generator and Motor and 90 ampere hour Willard Battery, starts much more readily than our 40/50 H.P., because of the fact that the engine is turned faster and we can get a more vigorous suction on the pilot jet. The flow through the jet we are using on our pilot jet carburetters is 27 to 30 pts. per hour when measured in the way described by Mr. Olley, this compared with there 50 pts. per hour obtained at Springfield. We know that the petrol we are using with 20% paraffin should be very much worse than the American fuel for starting. One reason why Springfield is using a larger jet may be because larger quantities of petrol are being collected in the vaporizer. This points to the necessity of having a high velocity in the pilot jet. hs.{Lord Ernest Hives - Chair} | ||