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).
Increase in throttle valve diameter for the 20HP carburetter.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan115 | |
| Date | 2nd May 1929 | |
| [Stamped: ORIGINAL] HS.{Lord Ernest Hives - Chair} ) FROM E.{Mr Elliott - Chief Engineer} [Crossed out: BY.{R.W. Bailey - Chief Engineer} )] Copy to SG.{Arthur F. Sidgreaves - MD} SECRET. E2/M2.5.29. 20HP. CARBURETTER. [Handwritten: X5080] [Handwritten, crossed out: X5050] 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 cylinder bore. The venturi passageway through the cylinder block should therefore start at 1.5" diameter at the carburetter end. This refers to 'P' series, and as far as we know requires no drawings from us, as 1.5" diameter was used once before on the original 'twentys'. E.{Mr Elliott - Chief Engineer} [Signature] | ||