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).
Issues with a countersunk screw, tappet guides, and engine vibration.
| Identifier | WestWitteringFiles\K\October1923\ Scan27 | |
| Date | 4th October 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} -2- EXPERIMENTAL REPORT Expl. No. 9770 REF: HGS/L.C4.10.23. with the cheese-head screw because of the difficulty of making the joints in the countersunk screw. The large retaining nut in the water pump drive is locked by means of a spring wire. We found that the hole for the wire had been drilled through and oil leaked out. We recommend that the wire is replaced by a locking plate fixed from the crankcase. Later - Tappet Guides. We have been unable to start the engine owing to the tappet guides becoming so stiff as to hold the valves open. We suggest the trouble is due to the fact that when the aluminium crankcase gets hot and expands the tappet guides go further down into the crankcase. When the engine cools down the crankcase contracts and squeezes the tappet guide. This is proved by the fact that the tappets are very stiff with a cold engine but become free if the engine can be warmed up. Vibration. We have run the engine without the slipper wheels on the friction damper. Under this condition we get crankshaft periods at :- 1100 to 1200 r.p.m. - distinct. 1600 " 1700 r.p.m. - bad. 2200 " 2300 r.p.m. - distinct.- after that up to 3000 r.p.m. we cannot feel any other torsional vibrations. With the slipper wheels fixed and adjusted, the engine appears to be quite smooth up to 2600 r.p.m., above that contd:- | ||