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).
Throttle valve diameter and venturi passageway for a 20 HP carburetter.
| Identifier | ExFiles\Box 103\4\ scan0051 | |
| Date | 2nd May 1929 | |
| Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to SG.{Arthur F. Sidgreaves - MD} +5050 E2/M2.5.29. 20 HP. CARBURETTER. X.5080 X.5050 Referring to the throttle valve diameter on the above, R.{Sir Henry Royce} thinks we should return to the 1.5" instead of the 1.375" at present standard, especially in view of the larger cyl. bore. The venturi passageway through the cyl. block should therefore start at 1.5" dia. at the carburetter end. This refers to 'P' series, and as far as we know requires no drgs. from us, as 1.5" dia. was used once before on the original 20s. E.{Mr Elliott - Chief Engineer} | ||