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).
Twin carburettor tests and camshaft comparisons on the 'Japan' engine.
| Identifier | ExFiles\Box 122\1\ scan0058 | |
| Date | 23th May 1930 | |
| COPY. To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/ACL. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Rs.{Sir Henry Royce's Secretary} E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} By.{R.W. Bailey - Chief Engineer} X1053 Hs{Lord Ernest Hives - Chair}/ACL.1/MJ.23.5.30. X.5080 X.1053. X.5090 X.5070 X 5230 TWIN CARBURETTER TESTS & CAMSHAFT COMPARISONS ON "JAPAN" ENGINE. We have carried out a number of tests with a twin Zenith carburetter on the "Japan" engine with a double three port type of induction system similar to that used in conjunction with the Solex carburetter on Phantom ll. The object of these tests was to find a suitable induction manifold for the six port head when using a twin carburetter of this type and to see what improvement was possible with a twin carburetter compared with the Std. chassis carburetter. We appreciated the possibility of the influence cam duration and cam angles could have when used in combination with three port carburation and a ramming type induction system. Consequently we experimented with what camshafts we had on hand to find the most suitable to go with the twin carburetter system. The tests were carried out on the Std. 'Japan' with 5.25/1 compression ratio and all the curves taken were corrected to open exhaust equivalent. Two exhaust manifolds were tested - both of similar shape but one of 1.350 inside diameter and the other 1.250 inside diameter. The carburetter was placed as close as possible to the main distributing pipe as we found from Phantom ll | ||