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).
Engine trouble and seizure on the Chassis B.8.GA Paris Trials Car.
| Identifier | ExFiles\Box 146\2\ scan0070 | |
| Date | 18th January 1937 | |
| P. des Swell To Bentley Motors Ltd. Derby......... Rm.{William Robotham - Chief Engineer} Levallois Re: CHASSIS B.8.GA - PARIS TRIALS CAR I herewith give you details of the engine trouble that developed on the above car. This car, as you know, is fitted with RR.56 N°7 bearing and a set of RR.56 connecting rods, the latter fitted with .0025" clearances and the main bearings with the standard .003" clearance. As you already know, the engine was beautifully smooth and exceptionally free from any period. I took great care in running it in and ran 745 Kms. entirely in town and there-abouts, never exceeding 3400 r.p.m. on top gear. We also put in graphited oil. Having planned a run on Sunday with some possible customers, I thought that I had better take the car out on Satur-day, just to see that everything was O.K. I therefore left Paris and, after having covered 30 Kms. (18 miles), I came upon a straight stretch of road and started picking up speed on top gear. I at-tained 4300 r.p.m. The water temperature at that moment was 78° C. and the oil pressure 33 to 34 lbs. Having reached 4300 r.p.m., I had to apply the brakes preparatory to negotiating a bend. I should like to add that, when I say this, I mean that my braking was very slight. At the same moment as I took my foot off the accelerator and started to touch the brake pedal, I was aware of rather effective braking, which I judged to be other than due to the brakes. I immediately got into neutral, cut off and let the car coast off the main road and into the side road. Incidentally, at that moment, the water temperature went up to 96° and the oil pressure down to zero. I tried the starting handle to find out exactly to what extent the engine had seized up, but there was nothing doing as it had seized hard. Having done the necessary to bring the car back to the Works, we are now in a position to state that this seizure was due to N°6 connecting rod, which seems to have picked up and drawn, N°7 main bearing being in a good condition. The total mileage covered since the engine was modi-fied is 776 miles and, as above stated, the mileage covered under normal conditions being 18 miles. I got on to Grylls on the telephone as you were out, as I wanted to know what the next move is to be. I will ring you up tonight in any case at Duffield 94 to discuss the matter with you. h.{Arthur M. Hanbury - Head Complaints} | ||