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).
Letter from the Experimental Department responding to a list of technical queries about engine components and settings.
| Identifier | ExFiles\Box 89\3\ scan0019 | |
| Date | 24th August 1936 | |
| X261 spec Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}17/KW. 24th August, 1936. Briggs S. Cunningham Esq., Cortachy Castle, Kirriemuir, Angus, Scotland. Dear Mr. Cunningham, Many thanks for yours of August 20th. Answering your queries - (1) The standard gasket is used with this head. We have never had the least trouble with gaskets so you will not require more than the normal amount of spares. I will ask them to let you have two or three as you will be taking the head on and off to try different compression ratios. (2) The valve clearances are still .004" and .006". If you are going to carry out any sustained high speed work, they should be opened up to .006" and .008". There is no special valve timing. (3) The car will run satisfactorily on standard valve springs. Actually those fitted are slightly stronger than standard, but this is purely to give a larger margin of safety. (4) We do not use any cement when replacing the gasket. (5) There is no special order for tightening the head bolts other than standard. | ||