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).
Faults with the Autovac system and vacuum windscreen wiper, including customer complaints and potential remedies.
| Identifier | ExFiles\Box 40\4\ Scan109 | |
| Date | 9th July 1925 | |
| Rm{William Robotham - Chief Engineer} Hilliar CJ. o/c to PN{Mr Northey} H.{Arthur M. Hanbury - Head Complaints} CWB4/LH{Mr Haworth}9.7.25. RE 'AUTOVAC'. I have read the attached report - Bs{A J. Barnes - Assistant Manager}2/LG4.7.25. This action of the Autovac is very noticeable and is receiving much unfavourable comment, from our customers. In some cases it altogether spoils the idling and slow running of the car. There is another fault which is possessed by practically every Autovac fitting and which appears to be peculiarly noticeable on the 'New PhantomCodename for PHANTOM I' chassis, possibly owing to the longitudinal disposition of the cylindrical Autovac tank, and that is a metallic rattle from the internal fittings, which appears to be inseparable from the article. Another instrument which is dependent on the induction pipe vacuum for operation, is the vacuum windscreen wiper, which, owing to the differences in vacuum under different conditions of running, works quite irregularly, and when pulling hard, particularly at slow speeds, stops completely. It may be considered to-day that the use of a windscreen is universal and it would be a distinct advantage if this could operate at a constant speed whatever the conditions under which the engine were running. With the exception of Item 2, which it may be possible to cure by improved design and construction, or by a different disposition or shape of the Autovac tank, a complete remedy could be found by the provision of a small vacuum pump driven from some auxiliary engine shaft or the gear box, and some such provision is considered desirable. We had for many years an air pressure pump of great reliability and no doubt this could be modified to serve the purpose required. It would always be possible to fit an emergency connection from the induction pipe to the Autovac for use in the very remote case of trouble with the little vacuum pump. CWB. --- | ||