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).
Tests conducted on an exhaust down-pipe baffle to determine its effect on an over-heating problem.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan139 | |
| Date | 25th September 1924 | |
| R.R. 493a (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF. Hg/Ra/LCSO.4.25 EXHAUST DOWN-PIPE BAFFLE. We have carried out a number of experiments on the car, both on the dynamometer and on the road to determine the extent to which the baffle in the down pipe can affect the over-heating problem. (A) The first test carried out was conducted on the road with an independent control to the exhaust baffle. A known test hill was climbed with the exhaust baffle set in the fully open position, the speed of the car being maintained at 25 m.p.h. on full throttle by means of the brakes. The exhaust baffle was then fully closed and the climb repeated. On this occasion the power had fallen off so considerably that practically no brake application was necessary to maintain a speed of 25 m.p.h. The temperature of the cooling system was accurately adjusted at the beginning of each run to a fixed number of degrees above atmospheric, and the rise in temperature during the climb was noted at fixed intervals. It was found that the rise in temperature in each case was identical, shewing that the heat given to the cooling water was the same for each condition; though the power at the road wheels fell off considerably when the baffle was closed. In these tests it will be observed that the road wheel resistance was varied to give a fixed engine speed, the throttle opening being constant. (B) The second series of tests were carried out in exactly the same manner, only the speed of contd :- | ||