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).
Secret internal memorandum outlining the 20HP car programme, detailing specifications for G.4, G.5, and G.6 series models.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan109 | |
| Date | 30th April 1929 | |
| SG.{Arthur F. Sidgreaves - MD} BY.{R.W. Bailey - Chief Engineer} } FROM R.{Sir Henry Royce} C. to WCR. HS.{Lord Ernest Hives - Chair} CX.{Major Len W. Cox - Advertising Manager} FN. R.{Sir Henry Royce} DA.{Bernard Day - Chassis Design} SECRET ORIGINAL 20HP. PROGRAMME. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 4, G.5., (= INCREASED BORE) & G.6. G.5. & 6. ARE 25HP. RATING. To avoid any delay or waste of time and money I give you the above in a few words as I understand will suit everyone best under the circumstances, and with which I agree. (1) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 4. (SERIES 'O'.) The 150 are G.4. as present standard, but smaller wheels, central lubrication, etc. at present being made (i.e. not the new head or the increased bore.) same power, 4% lower gear (equals 4% more torque.) Rather disturbing to Sales. (2) G.5. (SERIES 'P'.) Materials to be ordered for the following 100. as last mentioned, but with increased bore - 3.25", slightly longer chassis (3"), but no 'B' steering, i.e. my idea of only lower seats and roof, and always longer scuttle, resulting in better appearance, and all cars suitable for owner driver; also meets Major Cox's desire for more comfort in front seats. 10% to 15% more power at all speeds over (1). Not disturbing to Sales. (3) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 6. (SERIES 'Q'.) The final and complete move at present contemplated. Same as (1) and (2) but with new head and better induction, (cold distribution), less firing in exhaust, SS.{S. Smith} tappets running in oil, improved engine mounting (4 feet and rubber), new crankchamber, probably tubular connecting rods rather longer, and may include some axle work. 30% more maximum power at maximum speed, or say 15% more than (2). Altered appearance of engine somewhat disturbing to Sales. This work will leave WW. for Derby during May 1929. The G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 6. at WW. is not RR. quality - bad riding, noisy exhaust, feel too much engine and noise. Explanations later. I think a code word should be used for (3) and (4). India has been satisfactory, and 'China'and 'Japan'could be used, but other suggestions might be made. R.{Sir Henry Royce} | ||