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).
Letter from the American branch about explosions in the silencer when descending hills.
| Identifier | ExFiles\Box 1\3\ B001_X 93-page69 | |
| Date | 17th September 1926 | |
| ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. Oy8-E-91726 September 17, 1926 Mr. E.{Mr Elliott - Chief Engineer} W. Hives, Rolls-Royce, Ltd., Derby, England. Dear Mr. Hives: Re Explosions in Silencer Carburetter - Sec.5080 We have read with much interest your report on producing silencer explosions. The results are most interesting. We still feel however that the actual complaint on the road has to do with the fact that the governor does its best to close the throttle entirely in descending hills. The complaint is variable in different R.R. cars, and as far as we know is confined to the R.R. Other cars, which over here all leave the throttle a crack open, may in some cases "mutter" a little in the exhaust when coasting, but none of them have the R.R. habit of saving themselves up for several seconds and then giving one devastating crash which lifts the rear passengers and gives everyone heart failure. It is the latter complaint which is lodged against the R.R. cars in this country, and I think your tests go to show that this occasional and startling crash is due to a closed throttle. Probably it is rarer but more startling in proportion to the quality offit of the throttle. Working on this belief, we have cancelled the governor on our first O.H. valve test car, and arranged that the throttle shall always be slightly open (that is in a reasonable idling position) when the lever on the steering column is at the bottom. So far (1000 miles) we have had no crash from the exhaust in coasting, even down long hills with the car well warmed up. It is probable that the exhaust "mutters", but one cannot hear it in the car. MO/E Maurice Olley | ||