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).
Programme update for high-power cylinder head development and testing on a Bentley T.T.
| Identifier | ExFiles\Box 90a\6\ Scan059 | |
| Date | 11th August 1936 | |
| x262 51 RHC.{R. H. Coverley - Production Engineer} From Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}14/MA.11.8.36. BENTLEY T.T. The programme for the high power cylinder heads is now as follows :- Cylinder head Ex.22594A to be removed from B.3 on the bed and fitted with new, similar to existing valves, Ex.23266/7. New Rm.{William Robotham - Chief Engineer}53 valve springs which should be carefully inspected for any marks or indentures of the wire. Retain existing grummets which have bedded down and give clearance from choc-a-bloc in the full lift position. Both the head and the valves to be carefully inspected before final assembly and fitted into B.21 unit in Hall's car. We are hoping that by the time this is ready for fitment, we shall have received some corrujoint cylinder gaskets made so as not to protrude into the bore when the head is tightened down. The first of the chill-cast seat heads to be finished and fitted to B.3 unit for endurance to see if the chilling improves valve pocketing. It is also the first endurance on the same type of valves as will be run in the T.T. Ex.23266/7, which makes the job very urgent. Measurement of the valves from the face of the cylinder head to be taken so that following the endurance we can measure for pocketing and valve stretch. If it will not delay the completion of the head we should like to run 3 of the exhaust valves not stellited on the seats. The second chill cast seat head to be progressed and finished. Another head we are anxious to get hold of, is following the chill cast seat heads, we instructed for the pattern to be altered to Rm.{William Robotham - Chief Engineer}161 whereby the compression ratio is brought down to the standard figure of 6.5:1. From calculations this head should give a considerable power improvement over the existing standard head running at the same ratio. Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} | ||