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 to increase the speed of chassis 39.TW for Mr. Geoffrey Summers, focusing on ignition, engine power, and aerodynamics.
| Identifier | ExFiles\Box 47\1\ Scan056 | |
| Date | 11th October 1921 | |
| To BJ. from R.{Sir Henry Royce} c. to CJ. c. to Wor.{Arthur Wormald - General Works Manager} c. to Hs.{Lord Ernest Hives - Chair} c. to EP.{G. Eric Platford - Chief Quality Engineer} X4117 R4/G11.10.21. X. 2565 - RE CHASSIS 39.TW - MR. GEOFFREY SUMMERS. BJ/PY7/D7.10.21. Although we think the Bosch Magneto quite good enough and probably the Bosch plugs also, we do not believe that it will make a m.p.h. difference in the speed over another good ignition. Mr. Hives should investigate this to prove that there is no difference in the B.H.P. at the speed attained. Possibly the Bosch magneto had an increased advance over the original magneto fitted. This would be better for a speed of 2700. The best form of magneto for a big range of speed is the sleeve type that we have lately arranged to fit. This gives equally good sparking in all positions of the magneto, and a length of spark suitable for ignition plugs set with long air gaps, equal to that of the larger and heavier Bosch pattern. Most of the trouble with ignition is defective plugs, much more often than any fault of the magneto. Regarding the rest of Mr. Summers' letter to Captain Strong, unless we are able to offer some change in the gear ratio than that obtained by using larger wheels, I think it would be quite a good thing if Mr. Hives could see what can be done to meet Mr. Summers' wishes as regards increasing the speed of a fully equipped car. In addition to getting more power out of the engine at a speed of between 2750 and 3000 revs. which could be done simply, something could be done by investigating, say, the form of the splashers, the style of windscreen, and the position of the spare wheels, etc. or a body after the style of our L. and E.{Mr Elliott - Chief Engineer} or my | ||