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 performance and detonation issues of a Large Bore Bentley with a Van Vooren Body.
| Identifier | ExFiles\Box 90\1\ Scan172 | |
| Date | 18th November 1935 | |
| S/W X-63 To Rm.{William Robotham - Chief Engineer} from Sg.{Arthur F. Sidgreaves - MD} Copy to Crawford. Large Bore Bentley - Van Vooren Body. Sg{Arthur F. Sidgreaves - MD}7/E18.11.35 Thanks for Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}11/KW.16.11.35. I have given instructions relative to London traffic driving. It will be carried out by one of the men accustomed to the standard Bentley and, whilst we have no figures of the rate of wear of the present standard clutch, the driver should be able to give us a useful report as to how the clutch behaves generally in comparison with the standard. I had a long run on the car on Saturday. Generally speaking, it performed extraordinarily well. I was, however, rather disconcerted to note that it detonated rather readily, - and this on Ethyl fuel. I should be interested to know what is the difference in compression ratio compared with the standard Bentley and the higher compression head which I tried before - (I think like the one Lp.{Mr Lappin} has). It seemed to me that it detonated more easily than one would like on a car one wished to sell, especially bearing in mind that it was running on Ethyl. We had to put in 5 or 6 gallons of standard petrol on the way back and, curiously enough, it seemed, if anything, to detonate less. I told Kennett to fill it up on getting back with standard petrol but, in view of the appalling weather yesterday did not take the car out, so cannot at the moment say any more. I am sending the car down to Brooklands to-morrow to make some comparative tests with the standard Bentley. Sg.{Arthur F. Sidgreaves - MD} | ||