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).
Performance graph for a 1 5/8' SU carburettor on a 20/25 HP engine head, comparing two different induction pipes.
| Identifier | ExFiles\Box 103\4\ scan0113 | |
| Date | 7th March 1934 | |
| No1. UNIT CXIII SPEC. RHL/WSK K/AP. 5.12.33. 1 5/8" SU CARBURETTOR ON PORT SIDE OF 20/25 HP TYPE CYL. HEAD COMP. RATIO 5.7 : 1 CAMSHAFT OPEN EXHAUST (1) INDUCTION PIPE LEC 8657 (2) INDUCTION PIPE HS{Lord Ernest Hives - Chair} 1529 B.H.P. R.P.M. BMEP - LBS/SQ' | ||