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 required for 28-EX Silent Tappets from a BJ-55 unit.
| Identifier | ExFiles\Box 17\6\ Scan316 | |
| Date | 3rd November 1934 | |
| +7060 To RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Smth.1/KW.3.11.34. 28-EX - Silent Tappets. We are sending into the shop the cylinder head from BJ-55 unit. We should like this fitting to 28-EX after the following modifications have been made :- (1) Fit new plugs in the rocker ends, with oil holes .018" dia. (the present ones are .031" dia.). (2) The 10th and 11th hydraulic units have a plunger clearance of .00075" and belong to a different set from the others, which have .00125 clearance. Will you please replace these two units by those uniform with the rest. (3) We should like all the plunger valves testing for tightness. We suspect that the valve in No.10 unit leaks. (4) Remove the packing washers from under Nos. 10 & 11 valve springs. It appears that the tappets will be quite satisfactory with .00125 clearance, and would like you to hold up the third set you are making until we have confirmed this in the chassis. Hs{Lord Ernest Hives - Chair}/Smth. | ||