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 and testing of Zenith and Auto Klean petrol filters.
| Identifier | WestWitteringFiles\Q\February1927-March1927\ 56 | |
| Date | 2nd February 1927 guessed | |
| contd :- -3- It was found that, on an average, the Zenith filter choked up in one-tenth the time of the standardfilter. 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 shorter 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. (g) Auto Klean Strainer. We have also been trying one of the latest models of this type of strainer. The main objection to it is that owing to the cleaning device incorporated, the distance contd :- | ||