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).
Data sheet and discussion on carburettor specifications, acceleration figures, and the effect of throttle bore diameter.
| Identifier | ExFiles\Box 123\1\ scan0047 | |
| Date | 24th April 1940 | |
| - 2 - DATA SHEET (Continued) Main carburettor body type AA.{D. Abbot-Anderson}1. Throttle body type for 30 m/m throttles - AA.{D. Abbot-Anderson}1. for 36 m/m " - AAV.25. Plugs - AC.K.11 at .030" Ignition set at T.D.C. Delco-Remy distributor. Axle Ratio 9/37. Overdrive ratio .836. Rear tyres - Dunlop 7.00 x 16 - 1/3 worn. Tyre pressures - rear - 36 lbs per sq.inch warm. " " - front- 30 " " " " Rolling circumference of rear wheels - 90 3/4". Acceleration figures with large and small throttle bodies. 10 to 20 MPH in 4.0 secs 10 " 30 " " 7.3 " 10 " 40 " " 10.3 " 10 " 50 " " 13.85 " 10 " 60 " " 17.70 " 10 " 70 " " 22.15 " Handwritten notes: Rm{William Robotham - Chief Engineer}'s note. Overdrive or direct? Direct gear JAS. EIGHT CYLINDER CARBURATION. Final Stromberg carburettor specification for the eight cylinder engine is still held up by the induction pipe. It was, therefore, decided to study some fundamentals which would not be affected by actual setting of the main metering jets. The work may roughly be placed under two headings - throttle bodies, and idle systems. The same main carburettor body was retained through all the tests, i.e. main jets, by-pass jet and choke size remained the same throughout. THE EFFECT OF THROTTLE BORE DIAMETER. The amount by which the throttle bore may be reduced must ultimately be governed by top speed performance. If one is willing to sacrifice some of this top speed, very interesting economy is obtained. In the following tests dual Stromberg carburettors identical in every way save throttle bore, were used. It is important to note that this degree of sameness includes the idle systems. | ||