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).
Report page detailing engine performance, including speed, gearing, carburation, temperature and detonation.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan117 | |
| Date | 21th January 1928 guessed | |
| contd :- -4- running; the most noticeable one is at 37 m.p.h. 1900 r.p.m. on top gear when pulling. The period is of very short duration and it was definitely more pronounced when the car arrived, possibly due to the bearings not being tightened up so much as previously. This period is also noticeable on 2nd. gear at 22 m.p.h. The second period which is definitely worse occurs at exactly double the engine speed i.e. at 44 m.p.h. in 2nd. gear (3800 r.p.m.) - we have once been able to reach this speed on top gear down-hill, 74 m.p.h. (corrected speed approximately 80 by speedometer) and under this condition it was very bad. The carburation appears good, it is possible to accelerate suddenly from any speed above 8 m.p.h. with good results - accelerating suddenly from below 8 m.p.h. is not possible, it is necessary to use the accelerator pedal gently from the very low speeds. The carburation is good from stone cold; very little warming up is necessary to obtain the best results. The hot-spot, as can be expected from the design, does not heat up quickly, it heats up very slightly quicker than the water temperature, to approx. 75°C but its normal temperature is considerably higher than the water temperature. The oil rectifier being bolted to the exhaust manifold heats up quicker than the hot-spot and also reaches a higher maximum temperature. Although the car is very low geared one does not receive an impression of 'fussiness' owing to its general smoothness. Detonations are noticeable even with a perfectly clean engine, when using Shell-Mex, when the engine is slightly carboned they are bad. contd :- | ||