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).
Letter to The Autovac Mfg. Co. detailing experiments on two of their Autovac units and suggesting future modifications.
| Identifier | ExFiles\Box 40\4\ Scan222 | |
| Date | 7th February 1927 | |
| Y/3579. Expl: Dept: Hs{Lord Ernest Hives - Chair}/AJLL/LG. C. to Bq. 7th. Feb. 1927. Messrs. The Autovac Mfg. Co., Heaton Norris, Stockport. Dear Sirs, For the attention of S. Royle Esq., With reference to your letter of the 26th.ult. We have carried out some experiments on the two Autovac units received from you. The results we obtained agreed with those tabulated in your letter. We find the Measuring Autovac, although giving a better delivery than the standard unit at 3" mercury depression, falls below standard at depressions lower than 2" mercury; we have attributed this to the greater restriction in the petrol inlet port necessitated by the inclusion of the petrol valve - we have not done any investigation to prove this point. The results given by the unit with a moving float appear very promising, and as far as we have at present been able to find, there are no disadvantages. We are testing it out further on a car and will advise you at a later date on our opinion of it. With regard to the improvement in the standard unit resulting from opening out the suction and air holes. Tests we have made confirm your results. We have made considerable improvement by opening the suction hole out to .125" dia., we feel that all Autovac units supplied to us in future should have this hole opened out as much as is possible - .125" dia. is possible on the suction hole but not on the air hole. contd :- | ||