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).
Road test report detailing boiling issues, involuntary stops, and general performance on mountain roads.
| Identifier | ExFiles\Box 71\3\ scan0358 | |
| Date | 23th June 1926 | |
| COPY. Bt{Capt. J. S. Burt - Engineer}6/PD/23/6/26 - 3 - On the mountain roads the road surface was mostly good and speed not required. For these conditions we found 118-MC rather too long 12 ft. 6 inches wheelbase - and reversing on hairpins was necessary a good many times. Few very steep gradients were encountered and as the gear box was quiet, low gears were commonly used for descending hills. Neither brake required adjustment throughout the trip. BOILING. This was experiences once only in spite of the hot weather, and routes being selected to include the maximum of climbing. This one occasion was immediately upon stopping at the Monastery of the Grande Charteuse. Col du Galibier was closed by snow but the Lauteret was climbed. It was noticed on several occasions that after about 4000 ft. the temperature of the cooling water declined as a rule, though whether this was due to the cooler atmosphere when reaching the snow line, or to a decreased severity of the gradient, we did not establish - we thought the former. Although boiling was for the most part avoided, we only did so by observing very carefully the instructions which have been issued by R.{Sir Henry Royce} and circulated by W. of steps which may be taken to overcome severe boiling cases, and at the expense of using our gears far more than we should have chosen to, (for instance this car will negotiate a hill of one in twelve steadily on top gear but we found it advisable to resort to third whenever the gradient stiffened to one in 18 so as to avoid anything approaching full throttle). Moreover, we constantly had to drive with the mixture lever at strong instead of in the centre, and were surprised at the difference this made. We felt we should have liked another 15% or 20% cooling to enable us to drive as we liked. I am aware that it has been stated that boiling for several minutes does no harm to the car, but I am bound to record that as a private user of the car it requires a good deal of moral courage to feel perfectly content with a car which is boiling vigorously, when small French cars arrive at the same point without a sign of boiling, and their occupants have clearly seen that the Rolls-Royce is boiling, and are registering their interest and amusement. DETAILS OF INVOLUNTARY STOPS ON ROAD. The mechanical stops were due to the pin of the foot accelerator coming adrift and falling out so that the pedal no longer controlled the throttle. On two other occasions the platinum point contacts in the horn switch came adrift and shorted, so that the horn blew continuously. The electrical stops were probably all due to the same cause, though they manifested themselves differently twice by fuses Handwritten note: Note:- Car fitted with Tapley gradometer. | ||