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).
Visit to Coventry Climax Engine Co. regarding high power cylinder head design.
| Identifier | ExFiles\Box 134\2\ scan0095 | |
| Date | 11th November 1936 | |
| 8129 To E.{Mr Elliott - Chief Engineer} Copy to Hs.{Lord Ernest Hives - Chair} Rm.{William Robotham - Chief Engineer} Dr. BY Rm{William Robotham - Chief Engineer}/Edwards. E/PSN.2/MN.11.11.36. Visit to Messrs.Coventry Climax Engine Co., Coventry on Nov. 5th..1936. FIRM The writer and Rm{William Robotham - Chief Engineer}/Edwards paid a visit to the above with the object of obtaining information on the behaviour of the car engines built by this firm which have the High Power type of cylinder head with overhead inlet and side exhaust valves. A small firm as they are, has not the facilities for much experimental work but in overcoming troubles which have been experienced, they have gained some knowledge of this type of cylinder head. They emphasised the importance of keeping the exhaust valve seat away from the cylinder bore, a point which we have already appreciated and incorporated in our design. They were also emphatic that the exhaust valve on this type of head ran cooler than on the corresponding side valve as long as the combustion was right. If, however, the combustion characteristics of the head were wrong, then it was stated that the exhaust valve ran considerably hotter as indicated by the exhaust pipe temperature. Their experience was that this type of head was very prone to swirling in the combustion chamber which completely upset combustion resulting in increased consumption, uneven running at certain speeds and higher exhaust valve temperatures. They had run into this trouble on a cylinder head with the throat between the cylinder and the combustion chamber slightly offset, and by removing this offset the exhaust valve temperature was reduced and the head behaved in a normal manner. They also had similar trouble on a Ricardo design of head in which the throat was formed by a straight inclined wall and not swept round on each side of the inlet valve as in their own Whatmough type of design. They explained at some length the difficulties they had had with the patent position. It would appear that none of the patents are particularly strong but their hands are tied by an agreement to take out a licence from Whatmough for his engine. | ||