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 features and failures of engine unit PH II 22 after 5000 miles of testing.
| Identifier | ExFiles\Box 182\M18\ img053 | |
| Date | 14th July 1932 | |
| To Hs.{Lord Ernest Hives - Chair} From G.W.H. Hotel de France, Chateauroux, FRANCE. 14.7.32. REPORT ON 19-BX AT 5000 MILES. ENGINE UNIT NO. PH II 22. The following features and failures have occurred during this mileage. The half crankshaft period was first noticed after a mileage of 1,900. It has since gradually increased and at 4,500 miles would be considered a complaint. It was then dismantled - Low Inertia Damper to LOP.E.79915. LeC.3104 Strengthened Friction Plate to LeC.3104 LX.8680 Rabestos Friction Discs. E.79729 Damper Wheel modified to M.8679 E.76620/1 Driving dogs " " M.8681/2 E.77394 Pressure plate " " M.8683. E.76618 Friction ring " " M.8684. Driving spring load 32 lbs at 17.5" rad. Damping spring load 20 lbs at 17.5" rad. The characteristics of the damper had altered when examined. The damping spring load had increased to 27 lbs before the plates would move, when this load was broken down a friction load of 12 lbs remained, instead of 20 lbs. The stickiness is due to the polishing of the friction surfaces and the breaking down of the oil film between the friction surfaces. As it was useless to continue to run in this condition, we grooved one Rabestos disc and drilled a number of holes in the other to obtain the most satisfactory solution, the idea being to prevent the breaking down of the oil film. The damping spring load was made an even 19 lbs. The strengthened friction plate to LeC.3104 showed no signs of failure. It had also taken care of the thrust as there was no sign of the driving springs having bent, as was found previously. At a mileage of 3100 the engine misfired upon starting up from cold and continued to do so up to a speed of 20 m.p.h. It became worse and the car returned to the garage with the exhaust blowing past No.6 piston into the crankchamber. There was no sign of any compression in this cylinder. The engine was dismantled and No.6 piston taken out first. | ||