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).
Crankcase pressure tests and ignition timing adjustments.
| Identifier | ExFiles\Box 5a\4\ 04-page196 | |
| Date | 19th December 1934 guessed | |
| - 2 - We also drilled a number of holes in the flange, to try and get the oil away. The result however, has not shown much improvement. We have therefore, taken the crankcase pressure at various speeds with the following results:- 20 MPH. 3/32" Water pressure. 40 " 3/32" " " 60 " 1/4" " " 70 " 3/8" " " With the cap taken off the oil filler we had the following:- 20 MPH. 3/32" Water pressure. 40 " 1/16" " " 60 " 3/32" " " 70 " 1/8" " " We have suspected that the breather is not sufficient since being fitted in the top rocker cover. Re the Ignition Timing 21 G 1V. We have repeated the tests. The results are still hardly satisfactory, but the following is what is obtained:- 10 to 40 MPH. Top gear. Ignition advanced 1 inch on fly-wheel, i.e.- 8.75° With standard timing, retarding the ignition lever, the time is 19.1 seconds. With the ignition lever further advanced, i.e.- 4° more than standard, the time is 19.25 seconds. With full advance 8.75° more than standard, the time is 18.8 seconds. This is approximately the same result as we obtained during the previous test. W.H.Hancock W.J.H. | ||