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).
Modifications for a small universal single cylinder unit, specifically a 9:1 compression ratio Bentley cylinder head.
| Identifier | ExFiles\Box 133\2\ scan0127 | |
| Date | 12th December 1934 | |
| To BY.{R.W. Bailey - Chief Engineer} x1003 E/PSN.3/MN.12/12/34. H.{Arthur M. Hanbury - Head Complaints} Smith Copy to HHG. Hs{Lord Ernest Hives - Chair}/Hm.{Capt. W. Hallam - Head Repairs} Hs{Lord Ernest Hives - Chair}/Hm.{Capt. W. Hallam - Head Repairs} SMALL UNIVERSAL SINGLE CYLINDER UNIT. We send you herewith LeC 4249 showing a 9 : 1 compression ratio Bentley close centres cylinder head for the above unit. It should be noted that the combustion chamber roof has been left thick to simulate the conditions on 9 : 1 compression ratio head on the main engine. The exhaust valve guide has been extended further out into the port than is our usual practice in order to protect the increased length of exposed exhaust valve stem, the end of the guide being counterbored for approximately ¼" from its outer end. If burning is experienced with this extended guide it will have to be cut back. The turbulence ratio is 1.32 and as a result the inlet valve is very severely masked at full lift by the turbulent lips. The lips are also very thin and we shall be interested to see whether they will stand up without burning. E/PSN. Att: LeC.4249. | ||