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).
Confirming valve guide clearances for turbulent heads to eliminate valve clicking.
| Identifier | ExFiles\Box 66a\2\ scan0085 | |
| Date | 23th May 1928 | |
| N.75 an 24/5/28 Sft.{Mr Swift} [Struck through] c. Hs.{Lord Ernest Hives - Chair} c. BY/GS. [Struck through] X8060 BY18/G.23.5.28. TURBULENT HEAD - VALVE GUIDE CLEARANCES. I wish to confirm my conversation that the valve guide clearance should be :- Inlet = .0025" Exhaust = .003" These figures are being tried out by the Experimental Dept. with the object of eliminating valve clicking which occurs very badly for a short time during the interval when the tappet has not followed the heating up of the cylinder body, and therefore the tappet clearance is temporarily increased. We do not wish to alter our drawings for the moment until Hs.{Lord Ernest Hives - Chair} has confirmed his position, but all valve guides should be reamed to the above figures pending further instructions. [Handwritten Signature: By] BY.{R.W. Bailey - Chief Engineer} | ||