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).
Engine component issues, specifically tappet clearance and spark plug performance.
| Identifier | ExFiles\Box 11\4\ 04-page090 | |
| Date | 10th July 1932 | |
| x7941. To Hs.{Lord Ernest Hives - Chair} From G.W.H. Hotel de France, Chateauroux, FRANCE. 10.7.32. 19-EX. RE. TAPPETS. No.6 exhaust tappet has started to increase its clearance. The symptoms are wear of the tappet face. Push rods etc. are O.K. The clearance gained .006" during the day's run. We noticed, when we had the bottom half down, that the tappet faces showed scoring marks and did not look too good, but we have seen this condition before, and the actual depth of the score marks has been very small. It looks, however, that the strong valve springs are the cause of the trouble, as I have already reported upon the grooving of the valve spring washers. We are sending, as requested, two of the broken bolts taken from the side spare wheel carrier. H.D.C. LODGE PLUGS. These plugs have not shown any sign of preignition during the mileage to date. They started to misfire on the magneto side after approx 3,700 miles. They were found to have a gap of .025", (put in at Brooklands). They were reset to .020" (not cleaned) and the misfiring was cured. The electrodes show very little sign of burning. (The hexagon of the plugs are much smaller than standard. Our standard plug spanner is almost too large.) [Signature] G.W.H. | ||