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).
Tests using a small vacuum pump to improve petrol supply efficiency.
| Identifier | ExFiles\Box 40\4\ Scan158 | |
| Date | 3rd December 1925 | |
| H.R. 493A (70 H.P.) (D.H. 176-5) J.H.L. EXPERIMENTAL REPORT. -2- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/AJL/LG3.12.25 the compression space was reduced to 1/3 its original volume viz. from 28 c.c. to 8 c.c. The suction port of the pump was then connected up to the suction elbow of the Autovac and similar series of tests carried out to those in Table 1. In this system the petrol supply is constant for one particular engine speed and does not vary with throttle conditions. The supply increases with engine speed, i.e., the greatest amount of petrol is available when it is needed which is exactly the reverse of the conditions prevalent when employing the induction pipe depression. The results in Table 11. show a very marked decrease in the number of conditions under which the petrol supply will not cope with the engine demands, when compared with Table 1. These tests were carried out with a view to exploring the possibilities of the use of a small vacuum pump used in conjunction with a vacuum tank in order to produce a more efficient petrol supply and to do away with the ill-affects on the slow speed running of an engine due to connecting the vacuum tank to the induction pipe. contd :- | ||