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).
Troubleshooting leaking plunger valves on self-adjusting tappets.
| Identifier | ExFiles\Box 106\5\ scan0073 | |
| Date | 27th October 1932 | |
| RHC.{R. H. Coverley - Production Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/KT.27.10.32. SELF-ADJUSTING TAPPETS ON J.III. (Lec.3213). We have experienced trouble with the Plunger Valves leaking on three of the Plungers of the self-adjusting tappets to Lec.3213. It has been found necessary to lap the valves to the seats to prevent oil leaking past, but we have not met with any success with the three causing trouble. We should like to try new valves in the place of the leaking ones and suggest the valves are made with a very smooth and polished finish on the seating area and then should be lapped to their respective seats if found necessary. The valves can be tested for leakage by filling the plunger casing with oil and then pressing heavily on the top of the plunger, should the valve leak, oil will be seen rise up the centre of the plunger, should the plunger sink appreciably without oil showing in the centre of the plunger then there is too much clearance between the plunger and the casing. Too much importance cannot be attached to the necessity of good seating valves as the whole success of the scheme depends upon it. The clearance between the plungers and their casings should not be greater than that stated on Lec.3213. We have found that after running for some time several of the plungers showed hard marks on the lower edge and to overcome this trouble suggest that the lower edge should have a small radius. The finish of the plungers and the bore of the casing should be exceptionally smooth and polished. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} (R.Matthews) | ||