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).
Recommendations for adjusting valve and damper spring loads using distance washers.
| Identifier | ExFiles\Box 16\4\ Scan083 | |
| Date | 1st April 1929 guessed | |
| contd :- -2- valves. In order to obviate the necessity for using washers thicker than .150 under the valve cap, we recommend that the distance F.{Mr Friese} on the low pressure valve cap should be .130 less than on the high pressure valve cap. Then get any load we are likely to recommend, a reasonable thickness of distance washer can be used. The dimensions F.{Mr Friese} of the valve cap should be so arranged that with a .020 aluminium washer at W. the length of the spring with the valve closed should be : H.P. .910" L.P. 1.040" We shall then, by the insertion of distance washers, be able to get any load from 100 to 70 lbs. high pressure, and from 70 to 35 lbs. low pressure. The high pressure and low pressure valve caps should be clearly marked and similar marks made on the casing to prevent them being inserted in the wrong position. If this is done we think it will be sufficient as alterations in damper loading should only be carried out by Depots. We consider that all damper springs F.76548 after being checked for free length, should be tested for rating in a model rear damper. They should give a ball end load of 70 lbs. +- 4 in the low pressure valve with a working length of 1.040 i.e., with a .020 washer under the cap. Springs outside this limit should be discarded. contd :- | ||