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).
Review of design faults on the 25 HP car, specifically addressing issues with exhaust pipes and slipper wheels.
| Identifier | Morton\M13.2\ img029 | |
| Date | 26th January 1931 | |
| ORIGINAL. To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c.c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c.c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c.c. to Hy.{Tom Haldenby - Plant Engineer} Hs.{Lord Ernest Hives - Chair}4/MJ.26.1.31. x5770. JAPAN 111 25 HP. We consider that it will be useful to review the troubles we have with the present 25 HP. car so that in 'Japan 111' the design, wherever possible, can be schemed to eliminate these faults. The first complaints of importance are those shewn on the Quarterly Complaints List, because they are the users complaints. Exhaust Pipes. This is a very serious complaint in the hands of customers and we have no real solution for it. On the last car which ran 10,000 miles in France the exhaust manifold broke and the studs holding the manifold stretched badly. If we carry the exhaust pipe down the front end of the engine the most satisfactory scheme we have had of this type of exhaust is on the Silver Ghost with four wheel brakes. That scheme, which consisted of a manifold with a sliding joint in the centre, gave no trouble. In six months we have had 125 complaints of the 25 HP. exhaust system. Slipper Wheels. These wheels give far too much trouble. The adjustment is too delicate and not consistent. Quite a lot of trouble shows up by its affect on the engine gears. We are thoroughly in agreement to fix in the engine gears at the rear end. There is plenty of evidence to shew that with this arrangement we shall be able to eliminate the spring dive with all its troubles and expense. It should leave us with a simple damper on the front end. We see no reason why this damper should not be fixed outside the crankcase and work dry. It would have one great advantage of being easily accessible and it may help the design of the engine mounting and radiator mounting. The majority of engines are made with external slipper wheels. We do not anticipate that there will be any difficulty in getting the simple train of engine gears quiet. RIC. agrees with this. If we can by design eliminate engine gear and slipper wheel troubles we shall have made some good progress. | ||