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).
Details on using Cadillac-type automatic tappets and associated components for the Phantom II model.
| Identifier | ExFiles\Box 17\6\ Scan237 | |
| Date | 12th June 1934 | |
| COPY. X7060 12.6.34. Cadillac Type of Automatic Tappets for Ph.II. The best results obtained to date with regard to overcoming valves being held off their seats at the high speeds is by using the following combination, which enables running up to 3400 R.P.M. before trouble occurs. (1) E.80070 camshaft .429 lift (original std. Ph.II). (2) E.82458 inlet valves, Hs.{Lord Ernest Hives - Chair}1270 Exhaust Valves used in the cylinder head E.84568, 5.25:1 comp. ratio. (3) Hs.{Lord Ernest Hives - Chair}1301 valve springs (single) with .150 packings between the bottom spring cup and the spring, the length of the spring in the valve closed position being 1.850 and 1.420 in the full open position. The load exerted by the springs in these positions is 85 lbs. and 165 lbs. respectively, giving a rating of 186 lbs/inch, other details being - Single Parallel Springs. Internal dia. 1.110 + 10. Dia. of wire .192 6 SWG. 5 working coils and 3/4 of a coil ground square at each end, making a total of 6 1/2 coils. Free length 2.430. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. Corrected max stress = 95,800 lbs/sq.in. Hs{Lord Ernest Hives - Chair}/F.ll.Smith. | ||