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).
Unit test report for the Vulture (1) engine, detailing initial issues and modifications for the automatic adjusting tappets.
| Identifier | ExFiles\Box 123\3\ scan0100 | |
| Date | 17th January 1934 | |
| To Sg.{Arthur F. Sidgreaves - MD} From Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} X4704 Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}1/KW17.1.34. c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} UNIT TEST OF VULTURE (1). --------------------- This engine being urgently required for the chassis it was only possible to note any results of the special features incorporated without "getting down to the job". Alum. Cylinder Blocks (E.84222/3). Cylinder Liners (E.84226). There were no audible piston knocks either starting from cold or when hot, and the pistons were perfectly free throughout the run. This was verified by injection of extra oil to the cylinders at high speeds full throttle without the slightest power increase. Automatic Adjusting Tappets. R.R.Sch.466. At the commencement of the run the tappets would not function due to (1) Insufficient end play allowed by the distance pieces to enable the eccentrics to work freely. By collection of the drawing limits this can vary from .001 to .024" between eccentrics, so that the assembly drawings should state that the end play is not to be less than say .010", the distance pieces being made accordingly. (2) The eccentrics with white metal bearings were too good a fit on the rocker shafts and necessitated easing to be absolutely free. (3) Ball valves in the plunger not seating properly and without definite clearance. The ball valve lift should be .005 - .010" and when assembled perfectly dry it should be possible to hear the ball rattle lightly. After carrying out the above modification the tappets functioned very well up to 3000 r.p.m. it being necessary to prime the plunger before they started to work; i.e. hold the ball off its seat by a piece of wire, thus releasing the air from the under side of the plunger which is replaced by oil. The oil feed to the plungers was very uneven, some being flooded with oil and others starved. In the case of those with excess oil it was found that the oil hole in the pedestal came slightly above the top face of the plunger, this being cured by increasing the oil cushion clearance, the plunger assuming a higher level and so covering the oil hole. Cont'd.{John DeLooze - Company Secretary} | ||