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).
Test results for the Phantom III induction drain scheme under various petrol flow conditions.
| Identifier | ExFiles\Box 93\2\ scan0136 | |
| Date | 20th February 1936 | |
| X 308 To E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} HS{Lord Ernest Hives - Chair}/Ewdl.8/JH.20.2.36. Phantom III Induction Drain. We have tested the drain scheme to Lec.4937 with the following results. Under the most extreme condition, in the case of a punctured float and a full petrol flow through the needle orifice from the pumps, the 3/16 pipe and banjo from the float-chamber lid{A. J. Lidsey} is not large enough to release the amount of petrol flowing into the float-chamber without creating a back pressure in the latter. The back pressure increases the flow from the discharge jets from 15 pts/hr to 45 pts/hr. With the throttle in the open position the ball valve drains in the well of the hot box will cope with 52 pts/hr. even on a gradient of 1 in 5 without overflowing the well. If the throttle be in the slow running position when the discharge jets are overflowing at the rate of 45 pts/hr. as shown under the worst condition, petrol builds up on the throttle up to the point of overflowing the air intake. If the throttles in this condition are quickly opened the quantity of petrol which has built up swills down into the well and overflows into the induction pipe branches as it is impossible for the drains to cope with such a momentary rush of petrol. By increasing the pipe from the floatchamber cover to 5/16" dia. with the corresponding size of banjo connection on the cover, the pressure from the float chamber is released to such an extent that the flow from the discharge jets is a negligible amount, and flows past the throttles in the slow running position without any building up. | ||