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).
Preliminary test report on the 20 HP Lorraine car, evaluating the power unit, carburation, and crankshaft vibration.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan083 | |
| Date | 6th November 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c.c. to BJ. Wor.{Arthur Wormald - General Works Manager} c.c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c.c. to DA.{Bernard Day - Chassis Design} EY. c.c. to CW BAPN. c.c. to Hm.{Capt. W. Hallam - Head Repairs} ORIGINAL Hs{Lord Ernest Hives - Chair}/ Rm{William Robotham - Chief Engineer}1/LG6.11.26. 20 HP. LORRAINE. X3588 With reference to RL/M2.11.26. we have carried out some preliminary tests on the 20 HP. Lorraine car. The only feature in which we are interested is the power unit and possibly the clutch. The brakes, steering and suspension are unquestionably inferior to our present practice. The best feature of the power unit is its flexibility. The carburation is also superior to anything we have previously tried incorporating Zenith carburetters. This is particularly good when the car is cold, as is also the distribution. There is a pronounced crankshaft period on the car we have purchased at 1850 r.p.m. This seems so much more marked than anything we noticed on the car tried in France, that we are interested to see if a damping device is fitted which is not functioning in this particular case. We believe that this is not the main crankshaft period. Above 1950 r.p.m. the engine is remarkably smooth up to 3600 r.p.m. At speeds in excess of 3700 r.p.m. a period commences which we believe is the three per revolution or main crankshaft period but valve clatter somewhat masks its exact limits. In any case this speed can only be reached conveniently on English roads on bottom gear and is therefore a somewhat unreasonable test. contd :- | ||