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 valve timing, performance comparisons between J.A.P. and Austin engines, and development targets.
| Identifier | ExFiles\Box 134\1\ scan0077 | |
| Date | 24th January 1938 guessed | |
| 4. These were taken with the J.A.P. engine & others were taken with the Austin & showed the same effect. In that case the timing was altered by increasing the valve clearance. The actual opening at T.D.C. was about 1/32". The Austin's slow running was perfect, & I see no possible objection to having the exhst valve slightly open at T.D.C., while I have a strong objection to its being closed, namely, that [strikethrough]they[/strikethrough] having it closed, does not allow benefit to be obtained from the low exhaust pressure which I hope to get for you. Will you please go into this matter & let me know what you propose to do about it? We must get 40 BHP. per litre out of this engine or I'll sell the Alvis & buy a pony! I've got the Alvis engine in position now & should have it running in a week, but there are always so many small fittings to be made that the finished job [strikethrough]always[/strikethrough] takes longer than one expects. | ||