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).
Tyre wear and engine performance of a Cadillac, with comparisons to other models.
| Identifier | ExFiles\Box 125\2\ scan0162 | |
| Date | 24th November 1934 | |
| x1729a Hotel de France, Chateauroux, Indre. France. To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From GWH.{George W. Hancock - Head Chateauroux} 24th November 1934. Re tyres on the Cadillac. We have been running 7.50 x 17 Dunlop Buttress Tread tyres, with 35 lbs. pressure as was fitted in Derby. After those had worn out we have been running on 7.50 x 17 Dunlop "90" type. We take it that you meant in your memo, independant front wheel springing, not rear. We have already sent you photos of a front tyre. The wear is similar to the first time out of 28 EX. We hope the photos will enable you to see this clearly. The wear is even, and the mileage of the rear tyres has worked out equal to our Phantoms. The front are scrubbing, but the mileage is approximately the same as 28 EX. The "90" type have not run sufficient mileage to show up any peculiarities. I am afraid that the test will have to stop without we are able to procure new bushes and gudgeon pins for the connecting rods. We have built the engine up again, and shall take the car up to Paris for Hs{Lord Ernest Hives - Chair}' comments. It runs alright at medium speeds, but it would be fatal to thrash the engine as we have been doing during the high speeds. The chain drive on the Cadillac is definitely quieter than the 21 G 1V timing gears. Whether it will retain it or not is a matter of time, but considering the car had run 6500 before we started our test, mileage now 12,750, we should say the result is promising. The engine in the CADILLAC, before tappets became noisy and the water pump intermediate drive started to rattle, was dead quiet in listening in the driving seat. One did not know whether the engine was running or not. 21 G 1V. One can hear the dry metallic sound of the timing gears, one distinct tappet, but the worst feature is, one can feel the pulsations of the engine in both front seats. This is with the clutch out and taking no notice of the noisy Petrol pump. With the clutch in, the side shaft gears are very distinctive and uneven. We have learnt from Sr. that Hs.{Lord Ernest Hives - Chair} was coming to Paris, and our programme had been set out. We leave today with 21 G 1V, meet Sr. Sunday morning, and try out a 25 car, that a customer is turning down for poor acceleration and general performance. We are comparing it with 21 G 1V, also endeavouring to obtain an old 20 HP. car and compare results. We are taking the bumper bar and front cross member for the Bentley, fitting that and trying the car before and after. The Cadillac is following on Monday for Hs.{Lord Ernest Hives - Chair} to try comparisons. I have learnt that the car will not be ready for Leslie until later in the week, we, therefore, may not be able to try it. G.W.H. | ||