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).
Performance issues with the 'SS' vacuum pump and recommending modifications.
| Identifier | ExFiles\Box 14\6\ Scan043 | |
| Date | 1st January 1929 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} X7230 Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}6/LG4.1.29. 'SS{S. Smith}' VACUUM PUMP. X7510 We have been going over the points which must have attention before the SS.{S. Smith} can be considered a saleable proposition. The exhaust system and the exhaust heated throttle are both up to the Expl: Dept: A feature that we have tested however and found wanting is the vacuum pump. This fails to supply the engine requirements in two particulars :- (1) At max. speeds the delivery is insufficient for the engine requirements. (2) When the autovac has been run dry, the pump will not draw petrol to the autovac when the engine is turned over by the starter motor. Both these features are affected by the autovac which we have found xarkex vary in their delivery some 30%. Our tests however were taken on autovacs which are above the average. We shall however be able to reduce the discrepancy by instituting a production test for maximum efficiency. We recommend that the dimensions of the suction pump is increased somewhat. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||