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 testing, detailing issues and resolutions for rockers, plungers, and eccentrics.
| Identifier | ExFiles\Box 106\5\ scan0082 | |
| Date | 7th March 1933 | |
| -2- Hs{Lord Ernest Hives - Chair}/Std.1/KT.7.3.33. The rockers were then reassembled and run for half an hour at 3500 r.p.m. - the oiling trouble was entirely cured and the working of the tappets was improved - however, No.2 eccentric still shewed a tendency to tighten up; under load of valve spring, it being perfectly free when valve was not lifted - while No.6 plunger shewed signs of oil leakage - either at clearance or at plunger valve. Eccentrics etc. were stripped again and all high spots on shaft or eccentrics were again removed. No.6 plunger was checked for clearance and only found to differ by .0002 from stipulated clearance, so plunger valve was suspected. On examination this valve was found to be very badly pitted, and its machine finish was so bad that all the valves (plunger) were removed and examined. The finish was very rough, showing tool marks and was entirely unsatisfactory. They were returned to the shop and the finish improved, then re-fitted after being lightly lapped to seating. Also the plunger spring of No.6 plunger was replaced by a new one as it appeared to be very weak. Rockers were reassembled and run as before - this time for an hour at 3000 r.p.m. and 1/2 hour at 3500 r.p.m. - all the plungers were satisfactory and all the tappets were very quiet except No.2, which was very slightly noisy - again due to 'tightening up' under load of spring. The engine was then started up from cold and as soon as the circulating water was warm, while the oil was still cold, it was run at full throttle at 3000 r.p.m. until the oil was thoroughly hot - the brake reading being watched carefully all the time. Since the brake reading from cold to hot only shewed an increase of about 2 1/2 lbs. it was apparent that there was no tendency to hold the valves open. So that, except for the slight noise from No.2 tappet, the system may be said to be fairly satisfactory. It is proposed to attempt to cure this particular tappet by removal of high spots etc., but it is impossible to get rid of this 'picking up' tendency with the present combination of bearing metals for the eccentrics (nickel and case hardened steel). | ||