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).
Modifications to an engine and chassis, including a Knavs Carburetter, clutch, and braking system.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan115 | |
| Date | 12th July 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 9680 REF:Hal/LGL.2.24. This engine has the improved oil retainer at the flywheel end and so far has given no trouble. Owing to the proper carburetter only just being instructed, we have built up a further Knavs Carb. with the butterfly throttle incorporated. The size of the throats is .6" and 1.1" dia. We are using an aluminium induction pipe and exhaust heated bend. There is no butterfly valve in the exhaust system. We have fitted nozzles to the inlet and outlet exhaust pipes in order to get as much exhaust as possible to flow through the exhaust heated bend. With the present arrangement the bend does not warm up very quickly. We think it will be better when we have a butterfly. The controls are temporary ones which we have rigged up to suit the job. We are using a std. 40/50 silencer and cut-out. The top of the radiator is the same height as the standard 40/50 HP. but we have had to remove 1" of the matrix at the bottom in order to make room for the cross member to support the front end of the engine. We are using a sheet metal cross member for this car similar to the first one we fitted. The proper scheme was not ready in time. The starting handle arrangements were also fixed up at Derby. The clutch is a std. EAC. clutch with Ferodo linings. We had difficulty with the clutch stopping so we removed the first take-up springs. The clutch worked very well without these but we are testing them again on the next engine. The undershield was arranged by Derby. It is similar to the 20 HP. and encloses engine and gearbox. It was arranged also with the idea that the new features on the engine could not be seen from underneath. The gearbox is a standard 40/50. The rear axle is a 15-tooth - std. 40/50. The brakes have standard shoes alround. We arranged the leverages to the best of our knowledge at the time the car was built. The servo is lined with Ferodo. A set of shoes with cast iron liners is carried on the car as spare. Light springs are fitted to the pull off on the front axle. | ||