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).
Experiments concerning explosions in the silencer of a Phantom model, focusing on the effect of admitting air to the induction pipe.
| Identifier | ExFiles\Box 1\3\ B001_X 93-page60 | |
| Date | 23th August 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to Ev.{Ivan Evernden - coachwork} Oy. X93 HS{Lord Ernest Hives - Chair}/ACL/T23.8.26. EXPLOSIONS IN SILENCER OF PHANTOM. X8230 We have continued experiments on explosions in the silencer and have determined the influence exerted by a number of factors which are described below. Effect of air admitted to the induction pipe. For a given throttle opening and motoring speed, which causes vigorous and continuous explosions in the silencer, the admission of air to the induction pipe will stop the explosions. The minimum quantity of air necessary for this increases as the throttle opening increases. The apparent reason is that the admitted air results in a very weak mixture entering the cylinders and is also sufficient to provide circulation through the exhaust system and thereby prevent "building up" of an explosive charge. More air is needed as the throttle opening is increased because the proportion of combustible mixture to the admitted air is increased and forms a generally richer mixture which is sufficiently rich to build up an explosive charge in the exhaust manifold. A simple spring loaded suction valve was tried in the induction pipe and in order not to interfere with the normal light load slow running which takes place at a high manifold depression - approx. 19" of mercury - it was necessary to adjust the valve to operate only after this max. slow running depression had been reached. Contd. | ||