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).
Modifications to the 40/50 standard induction pipe to improve petrol distribution and prevent misfiring.
| Identifier | ExFiles\Box 183\M22\ img161 | |
| Date | 5th October 1922 guessed | |
| -3- the engine in order that the weakest cylinder will fire regularly, is drained into the vessel and wasted. Once the petrol which has been measured out by the carburetter is in excess of the engine's requirements it can only be wasted. Very early on our tests showed the thing to strive for is good 'contour' distribution and not to make use of the vapouriser scheme in order to correct bad distribution. Our experiments in this direction proved that if we make the present 40/50 standard induction pipe so that all the branches are right angles, and the pipes which passes over the cylinder is made to project into the branch pipe, we can produce consistently improved distribution over the present standard pipe. We have tested a number of these pipes and we get definite improved results. We are recommending that this modification to the induction pipes shall be adopted as standard in conjunction with the exhaust heated throttle. When we fit the drain pipes from the induction pipe bends leading to each cylinder to a boiler, it is still necessary to have a vent pipe from the top of the boiler back into the induction pipe. If we do not have this vent pipe, the boiling of the petrol prevents any more liquid passing down. We found with this vent pipe fitted we could get bad missing fire under certain extreme conditions. This was caused by liquid petrol coming from the boiler and entering the induction pipe via the vent pipe. We were surprised that any petrol in the form of liquid could come from the | ||