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).
The causes of explosions in the exhaust manifold and silencer.
| Identifier | ExFiles\Box 1\3\ B001_X 93-page59 | |
| Date | 23th August 1926 guessed | |
| contd :- -5- the exhaust dilution as in the other cases. A certain amount of fuel will line the induction system, particularly so if fairly wide throttle and low speed has been used previously. Closing of the throttle will result in a high induction pipe vacuum which would evaporate the fuel in the system and in all probability when added to the cylinder and manifold contents would produce a combustible mixture and explode the 'missed' charges in the exhaust manifold. We have proved that the supply of charge does not come from the carburetter once the throttle is shut properly, by stopping off both jets immediately the throttle is closed. The number of explosions after the throttle is closed is seldom more than two and with a properly fitting throttle we have found it quite impossible to obtain continuous explosions in the silencer with a shut throttle. It is usually assumed that the silencer explosions are worse with the cutout open. We have taken careful note of this and are of the opinion that there is no difference in the actual explosions, and with the cutout closed it is only the silencing effect of the silencer which allows only the more vigorous explosions to be audible in the car. Although there are possibly other factors influencing the trouble, the above notes briefly outline the work we have up to the present complete. Hs{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||