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).
Fuel deposit issues in a carburetter from different fuel types and mixtures.
| Identifier | ExFiles\Box 103\5\ scan0173 | |
| Date | 16th December 1938 | |
| GWH.{George W. Hancock - Head Chateauroux} (K). c. H1/Mr. Whitehead BY.12/G.16.12.38. Referring to Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}23/N.14.12.38. and Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}24/N.14.12.38. I note that you have returned the body of the S.U. carburetter showing a gummed up throttle. I will directly interest myself in this matter, as it certainly contains unusual features with which I myself am well acquainted. For instance, I have done 15,000 miles on National Benzole and a further 20,000 miles on Discol. I have not had the slightest trouble from the continuous use of either fuel. With regard to Coaline, this I am inclined to think if used may cause deposit. I have heard rumours of it, but whilst I have done one or two long runs on Coaline I have certainly not had a sufficiently long experience with this fuel to give it a clean sheet, as I can in the case of National Benzol and Discol. My experience with Coaline is limited to using two complete tanks full of this fuel. In both instances I ran from south of London to Derby. In one case I had previously used National Benzol and had about 3 gallons in the tank, the balance being 10 gallons of Coaline which was added. In the second case, I had about 2 gallons of Discol in the tank, and filled up to 16 gallons with Coaline, but I experienced no trouble. In regard to your suggestion that it is the mixing of Discol and Coaline which causes the trouble, I would like to investigate this particular point, and if you could bring some Coaline up with you, say 2 gallons, I would arrange for the Laboratory to make intensive tests on mixtures of :- (a). Discol and Coaline. (b). National Benzol and Coaline. (c). Discol, Coaline and National Benzol. From an examination of the carburetter, there is obviously a stiff varnish deposit, which sticks up the throttle very thoroughly. I am showing this to the Laboratory to see whether they can dissolve it and explain what it consists of. I will then, after dissolving the gum return the carburetter body to you. BY.{R.W. Bailey - Chief Engineer} | ||