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).
Two types of Autovac petrol feed units received for testing to improve supply on the Phantom engine.
| Identifier | ExFiles\Box 40\4\ Scan211 | |
| Date | 2nd February 1927 | |
| Autovac Petrol In view of the limitations of the present Autovac petrol feed system, on the Phantom, with regard to its ability to supply the full petrol demands of the engine, we have been in communication with the Autovac Co. in the hope that they could supply us with something better than at present. In reply we have received for testing purposes two types of Autovac units, differing slightly from the standard as follows:- 1) Autovac with a moving float. This is similar in construction to the standard unit with two exceptions a) The float instead of being permanently fixed to its spindle is a loose fit on it, allowing the float to move up and down the spindle; by this means the petrol drawn in per stroke is increased in proportion to the distance the float is allowed to slide up and down its spindle. On the unit supplied the float moves 1.20" relative to its spindle. b) The float chamber is made deeper than standard by the amount the float moves relative to the spindle i.e. 1.20". 2) Measuring Autovac. This is the Autovac unit which is designed for use with the Autovac Galometer. The working stroke is longer than the standard Autovac having been designed to supply .002 Galls per stroke which is approximately | ||