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).
Race regulations concerning cylinder capacity tolerance and permitted fuel specifications.
| Identifier | ExFiles\Box 160\3\ scan0307 | |
| Date | 29th May 1935 guessed | |
| (5) b) Minus tolerance. - The car must remain within the category corresponding to that of the basic cylinder capacity (see art. 15). (handwritten) normal The fitting of cylinder liners is allowed, whether the standard type includes this arrangement or not. Should the minus tolerance be exceeded, the car will be admitted but will be considered as having the normal cylinder capacity as defined in the catalogue. 6. - Cars must comply both with the spirit and the letter of the present regulations. In the event of the bona fide or comfort of the bodies being challenged, the race Stewards shall be sole judges and their decision will be arrived at 24 hours before the start of the race at the latest. This decision shall be final. FUELS Art. 5 b. - Throughout the duration of the race each and every one of the competing cars is under the obligation of employing the same fuel which must be one of the following: a) " Standard " touring fuel b) Benzol c) " Super-Esso " supor motor-fuel d) Ternary fuel e) " Standard " Gasoil The definition of these fuels is as follows (I) : a) " Standard " touring fuel : Constituted by touring petrol complying with the specifications of the decree of the 14th. November 1935; said petrol must be limpid and neutral, free from sulphurous compounds detectable by the copper blade corrosion test, leaving no deposit and fulfilling the following conditions : The distillation test by the standard (A.F.N.O.R. B6 II Engler bulb) method should yield : At least 10 per cent in volume of products distilling below 65 degrees Cent., including Wastage; At least 50 per cent in volume of products distilling below 120 degrees Cent., including wastage; At least 95 per cent in volume of products distilling below 185 degrees Cent., including wastage. The Octane number, measured by the C.F.R. method (Motor Method) must be at least equal to 60 with a tolerance of minus I. ... (I) Should the above specifications be altered by Departmental Order prior to the 1939 Le Mans 24 hours race this would naturally be taken into account. | ||