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).
Specifications for back axle, valve timing, valve contours, and radiator weight.
| Identifier | ExFiles\Box 124\3\ scan0010 | |
| Date | 26th April 1917 | |
| -2- Back Axle - Helical Gears. Cantilever springs anchored at both ends - brackets supporting springs on axle tube have a limited movement. "U" type of torque tube suspension, with two diagonal stays - side brake internal, foot brake external - both on back axle (star differential). 2 qrts. of amber gear oil put in back axle. Weight of Radiator 44 lbs. 2 ozs. full of water 59½ lbs. Centre Bracket broken - supporting front end of engine. Valve Timing - .015" clearance. I.O. 13° P.T.D.C. E.O. 48° B.B.D.C. I.C. 25° P.B.D.C. E.C. 2° P.T.D.C. Valve Contours. No clearance in tappets. Degrees on Camshaft. Inlet. Degrees on Camshaft. Exhaust. 0° .969 0° .929 5 .969 5 .928 10 .969 10 .926 15 .964 15 .908 20 .944 20 .886 25 .916 25 .857 30 .878 30 .811 35 .8375 35 .767 40 .797 40 .729 45 .758 45 .700 50 .730 50 .676 55 .711 55 .662 60 .701 60 .658 65 .706 65 .6585 70 .718 70 .658 75 .739 75 .658 80 .764 80 .659 85 .800 85 .668 90 .845 90 .685 95 .887 95 .708 100 .922 100 .747 105 .949 105 .785 110 .963 110 .830 115 .968 115 .871 120 .969 120 .892 125 .909 130 .928 135 .929 R.R. 235A (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. | ||