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).
Brief summary of road tests conducted on various 6-port induction manifolds.
| Identifier | ExFiles\Box 104\2\ scan0137 | |
| Date | 29th June 1935 | |
| 4523 To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation} Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}4/KW.29.6.35. 18-G-IV. Brief Summary of Road Tests on 6-Port Induction Manifolds. (1) Standard Bentley manifold with two SpectreCodename for Phantom III carburetters; even slow running at 4 m.p.h. .015" tappet clearance. (2) Sheet metal manifold (Hs.{Lord Ernest Hives - Chair}1914 dimensions) with downdraught Stromberg carburetter. Even slow running at 3 m.p.h. .015" tappet clearance. V.1743 water heated extension made no appreciable difference. (3) Hs.{Lord Ernest Hives - Chair}1818 manifold with twin Solex carburetter. Slow running uneven and lumpy (Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}14/KW.7.5.35). (4) Ex.18310 manifold with Stromberg carburetter (Hs.{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}14/KW.16.5.35) & (Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}9/KW.27.5.35). Very good slow running at 3 m.p.h. .015" tappet clearance. This is the best manifold for dead slow running. Extension deflectors make no appreciable difference. Worst feature is loading up part throttle. Reducing the central capacity spoils the good slow running but practically cures loading up. Drain and constant leak made no difference. (5) Hs.{Lord Ernest Hives - Chair}1914 cast manifold inclined 17° with Stromberg carburetter. This is worse than Ex.18310. Slow running uneven and lumpy. Distribution bad at low speeds full throttle. Hs{Lord Ernest Hives - Chair}/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Ratcliffe. | ||