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).
The performance and issues with harmonic crank dampers, carburation, and water systems on various car models.
| Identifier | ExFiles\Box 135\2\ scan0207 | |
| Date | 14th August 1940 | |
| - 2 - R.R. Harmonic type Crank Damper. The R.R. harmonic type crank damper failed on 11-B-V and 4-B-50 cars, these were replaced by R.R. Studebaker type dampers which are quite satisfactory. On 9-B-V car, we are running a Humber type damper, set at 50 lbs/ins. with four loading springs instead of three, and this also appears to be satisfactory. CARBURATION. We consider the set-up on 4-B-50 to be satisfactory. This consists of 1½" bore induction pipe, and 1.1/32" carburetter chokes. The camshaft has a 20° negative overlap with a tappet setting of .010" inlet and .012" exhaust. Further suggested improvements to this scheme are a square section induction pipe with buffer ends and 5" more of water jacketing. These conditions should give better part throttle economy and distribution, see Report Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden}1/JMS.2.6.40. 11-B-V car with three S.U. carburetters fitted, was quite satisfactory, both for performance and consumption. Further development work is required on the Air Silencer. 1-R-1 car loads up badly in the induction pipe, this is due to a horizontal baffle in the centre of the pipe. This was incorporated with a view to improving part throttle distribution but instead it made it worse. This car should be fitted with a Standard Wraith pipe 1.6" bore. S.U. carburetters have again given us a lot of trouble due to piston sticking, 11-B-V three times, B.22.AW. three times, and 9-B-V twice, in which instances the trouble has been cured by lapping the piston into the pot, and refacing the bottom of the pot. Some distortion seems to take place in service, as this trouble recurrs. WATER SYSTEM. Water pump bearings have been very troublesome, having failed on 9-B-V, 30-G-VII, 3-B-50 and 5-B-50. The bearings apparently will not stand up to the load of the fan. The Vauxhall water pump has never been fitted to any of our cars, and is at present at Park Leys. The latest B.80 scheme to SCD.1398 has now been fitted to 11-B-V and 9-B-V, At the moment both appear to be satisfactory. Belt squeaks. The fitting of cast iron pulleys has cured fan -continued- | ||