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).
Technical comparison of silent tappet specifications for various engines.
| Identifier | ExFiles\Box 17\6\ Scan169 | |
| Date | 29th November 1933 | |
| FILES: X7060 SILENT TAPPET COMPARISONS: Spring Load Only (Cadillac & Pierce Arrow, spring load taken at the same figure as J.III) Eccentric Eccentric Pierce Arrow Phantom Cadillac .47: 1 J.III .267: 1 Direct Acting. Direct Acting Dia. Of Plunger. .6234 .5245 .4995 ø .4995 Clearance between Plunger and Case. .0016 .00075 .002 .0005 Clearance Area A.{Mr Adams} sq.in. .00313 .00120 .00314 .00079 Effective length of Plunger. .932 .650 .750 .545 Max. load on Plunger (lbs.) 58.8 33.45 125 149 Max. Press of oil beneath plunger (P.lbs/sq.in) 192.8 155 637 760 (Max) Leakage Factor PA{Mr Paterson}/L. .647 .286 2.67 1.103 Lift of Ball Valve. .015 .005 ø Plunger return spring : Free length = .95 - Load = 0 Fully compressed = .527 - " - 7 lbs. Taper Spring (Rectangular Section Wire. Inner Dia. (Small .467 (Depth .080 Thickness .040 (Large .600 Total 5 coils | ||