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 problem of gudgeon pin knocks in test cars and a recommendation for a solution.
| Identifier | ExFiles\Box 171\3\ img094 | |
| Date | 18th April 1921 | |
| XH190 Hs{Lord Ernest Hives - Chair}/LG18.4.21. X.4190 - GUDGEON PIN KNOCKS. We are having considerable trouble with gudgeon pin knocks with cars on test. In order to try and avoid these occurring whilst cars are on test, the gudgeon pins have to be fitted to .0001". The works are complaining that the limits are unreasonable. We are inclined to agree with them because as soon as the piston reaches its normal working temperature, there is about .002" slack. One suggestion is to fit the gudgeon pins tighter and to heat up the pistons with hot oil to put the gudgeon pin in or take it out! This is not a very straight-forward job and we think it will cause a lot of trouble when the cars go into service. We have, up to the present, made and fitted about 20 sets of gudgeon pins fitted with the locking screws which expand the ends. The Test Department have used these on cars which they have had a lot of trouble with gudgeon pin knocks, and so far, they have not had any complaints. We recommend that these gudgeon pins are adopted as standard. Although this arrangement is open to criticism, it should be remembered that the present standard locking screw distorts the pin equally as much only it is in the opposite direction. Hs.{Lord Ernest Hives - Chair} | ||