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).
Cylinder head EB.2050 detailing service failure risks and standardization decisions.
| Identifier | ExFiles\Box 86\1\ scan0132 | |
| Date | 23th February 1935 | |
| - 2 - E.1/HP.23.2.35. EB.2050 cylinder head itself in addition has certain features involving risk of failure in service, as follows:- (1) The thickness of metal between the valve seats which we have increased by .062 on LeC.4319 and 4348. The 9 to 1 head cracked at this point, but this is thought to be due to a faulty jacket core. (2) The roof of head and oil feed boss to the rocking gear is too close to the central exhaust bend leading to restriction of flow along top of jacket if steaming and possibly to overheating oil feed to rockers. (3) Sparking plugs .2 lower than standard causing front plug to foul leads on distributor. The difference in weight between EB.2050 and LeC.3662 is accidental, and probably to be accounted for by the fact that the latter was made by rubbing away the sand from standard cores for the alteration. There is no design difference to account for it, and it would not apply on production. I am, therefore, signing standardisation X.219 with the proviso that the overall depth of the head is to remain standard which will reduce the alteration required for applying the higher compression to merely that of changing the head and valves. E.{Mr Elliott - Chief Engineer} | ||