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).
Dynamometer tests of a hot throttle system for gas consumption, horsepower, and temperature.
| Identifier | ExFiles\Box 50\3\ Scan270 | |
| Date | 15th January 1924 | |
| To: Messrs. Olley / Nadin / Bagnall / Hulley / Southern / Harkness CC Mr. Belnap From: Mr. Caswell Handwritten Note: hurs C. +4305 Please send this in a personal envelope to Mr Hives at Muckleover by Jan 19. Dynamometer Tests of Hot Throttle The following tests for gas consumption, horse-power and induction pipe temperatures with the Derby Hot throttle plus Springfield modifications were made on a new chassis, No.149 JH. On the branch of the Derby induction pipe where it joins the main pipe a short copper tube was sweated and filled with mercury in which a thermometer was fitted. To keep the fan from cooling this several thicknesses of cloth were wrapped around the tube. The Derby induction pipe was equipped with Springfield vaporizers and boilers. The butterfly valve in rear exhaust stand pipe and connection from hot throttle to front silencer were both removed. The exhaust from the hot throttle was lead away thru a short length of pipe - about 24" - the end being fitted with a cock. 1st Test. This was made with everything standard. 2nd Test. Was made with Derby Hot throttle and Springfield modifications, as mentioned above, but the cock was open on end of exhaust pipe from throttle. 3rd Test. Same as No.2 only cock was closed at end of pipe from throttle. 2nd Test. Within about 20 seconds of starting the engine, the lower part of the hot throttle was slightly warm, the top remaining quite cold for two or three minutes. At this stage the engine appeared to run with more certainty than a standard job will do, as the water heated (or cooled) throttle remains cold for a considerable time. The throttle under test 2 conditions does not heat up anything like the standard Derby scheme, but appears to be midway between it and our standard Springfield arrangement. A considerable increase in power was obtained with varying results as to gas consumption. The highest induction pipe temperature reached with engine running during this test was 96°F. {Mr Friese} at 2000 R.P.M. With engine running light at a low speed induction pipe temperature has reached 140°F. {Mr Friese} All tests were made with the hood removed from the engine. | ||