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).
The performance, particle analysis, and road testing of a Zenith petrol filter.
| Identifier | ExFiles\Box 44\1\ Scan111 | |
| Date | 22th September 1929 | |
| contd :- -3- amount of foreign matter. No attempt was made to reproduce road vibration in these tests. It was found that, on an average, the Zenith filter choked up in one-tenth the time of the std. filter. A micro-analysis of the foreign matter passing each filter respectively shewed that a very definite benefit can be expected when the Zenith is employed. We found that hairs will pass the Zenith filter, but relatively few, and they do not exceed .001 in dia. being also shorten than those which pass through the gauze. Therefore on the whole we should not expect them to clog the jet. (f) Road test - Zenith filter. It will be apparent from previous tests that the Zenith petrol filter results are a definite improvement over our standard practice in every particular but one, i.e. the capacity before choking. However it appeared to us, and the makers claim, that under the car vibration conditions this filter might, to a certain extent, be self-cleaning. We therefore completely choked up a Zenith petrol filter on the testing rig, and having done so, fitted it to a car. The filter is cleaning itself and is now running satisfactorily for ordinary conditions. The restriction occasioned by this filter when clean under a delivery of 2.8 pts/min. or over double the approximate maximum requirements of the car is equivalent to a 2 ft. head of petrol. Therefore, though for normal requirements the autovac head will just about deal with the restriction resulting from this fitment when clean, there is not too large a margin for obstruction. RS{Sir Henry Royce's Secretary} contd :- | ||