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).
Comparison of the Goshawk and Dorris schemes for self-draining induction pipes.
| Identifier | ExFiles\Box 48\4\ Scan029 | |
| Date | 16th December 1921 | |
| X4227 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to GJ. c. to E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to FN. c. to HST. for R.R. Inc. X4305 X4227 for attention of OY. Hs{Lord Ernest Hives - Chair}3/LG16.12.21. INDUCTION PIPES. X4390 X1449 "We do not find that the self-draining pipes similar to those fitted to the Goshawk act in the same way as the Dorris scheme. The point in the "Dorris" scheme is that the petrol is drained down a channel or pipes in which there is no velocity of air passing to hold the petrol in suspension. For instance, if an engine is run with an uptake induction pipe, we still get liquid petrol creeping up the walls of this pipe. It is not until the engine stops that the liquid petrol runs back into the carburetter; so long as the engine is running, that petrol clings to the side of the pipe. If we insert a trap scheme similar to the "Dorris", we can then collect the petrol which clings to the side of the pipe, the whole time the engine is running. We have tried fitting a Dorris trap just above the throttle on our engine so that we trapped all the liquid at one point instead of six, and then drain it into a vaporizer. We find that with this, when starting up cold, we could not get enough petrol to run the engine because practically the whole of the petrol was collected in this trap. With the usual hot spot schemes, there is not sufficient time when the petrol is travelling over the hot spot for it to be completely vaporized - the Dorris scheme does not have this fault. Then, of course, there is the other advantage that the charge is heated up less, which prevents loss of power and reduces the tendency to detonate. At present the Goshawk pipe is not as good as the latest 40/50 H.P. contd:. | ||