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).
Specification details for the Japan 1 second half 'T' series 25 HP cars, covering frames, crankshafts, and cylinders.
| Identifier | Morton\M13.2\ img045 | |
| Date | 8th May 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} . By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} ORIGINAL Hs.{Lord Ernest Hives - Chair}5/M.J.8.5.31. X5440. X4554. JAPAN 1 SECOND HALF 'T' SERIES. Replying to R1/M7.5.31. It is very important that the specification for the 25 HP. cars on the second half 'T' Series should be completed at once. The time for ordering material is already overdue. We should be taking a certain amount of risk if we ordered the material before we either see or try a car similar to what is to be produced, but as we are so far behind there does not appear any other alternative but to take that risk. As regards ordering the material, the first point to be considered is whether any of the alterations will effect the bodies which are in stock. This point is raised by the mention of the 3" longer bonnet and universal dashboard, which so far we have not seen. FRAMES. It is proposed in future to use cold pressed side members made in manganese steel. We are at present running such a frame on the bumper test. The point still to be settled on the frame is the alteration of the front cross members to allow for the deeper radiator and diamond engine mounting modifications to standard handle - which, if it is carried out the same as P.2 will alter the dumb irons. In view of this, it would appear that at the moment it is only safe to order the side channels themselves. CRANKSHAFTS. I think we should assume that any extra power will go into increased acceleration, the rear axle ratio remaining the same. On the 25 HP. we should definitely have balance weights. So far the only crankshaft we have run is with twelve balance weights. We believe the proposal is to use eight. The question of balance weights should be decided before crankshaft forgings are ordered. CONNECTING RODS. The crankshaft will be the large pin type which will mean new connecting rod forgings. These, on 'Japan', are also slightly longer. CRANKCHAMBERS. We know of no alteration of this except what will be called for by the new engine mounting. CYLINDER. 'Japan' type, the same as we have run. The cylinder head - instructions have been issued to the Pattern Shop to produce a 'Japan' head in cast iron. | ||