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).
Analysis of engine cooling system performance, focusing on water flow rates, restrictions, and pump delivery in Phantom and Spectre engines.
| Identifier | ExFiles\Box 149a\1\ scan0057 | |
| Date | 12th October 1934 | |
| -3- HS{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}24/KW.12.10.34. On Phantom it was necessary to restrict the flow in order to stop splashing in the radiator, resulting in loss of water down overflow pipes. The restriction LeC.3918 reduced the flow at 5500 RPM from 575 lbs/min. to 461 lbs/min. From this it would appear that approx. 500 lbs/min. would be the maximum flow necessary on SpectreCodename for Phantom III II now giving 321 lbs, at 4000 RPM, and only 231 lbs. SpectreCodename for Phantom III I. The existing pump would be quite capable of delivering sufficient water at high speeds if the restrictions through the engine were reduced. If the flow at 4000 RPM, in tests 1, 2 and 3 be plotted against the back pressure on the pump, it is found that if all the restrictions were removed giving no back pressure, the pump would deliver over 700 lbs/min. Of the 51 in.hg. back pressure at the pump, there is approx. 15" in the cross pipe, 9" through the oil cooler matrix, 9" from the oil cooler box into the cylinder head, 8" between cylinder head and the top water pipe, and finally 10" between the top pipe and the tank. The heat flow tests taken on SpectreCodename for Phantom III I (curve S.P.2) - the water temp. at the rear end of the cylinder head is 20oC. higher than at the front outlet end, which indicates that the outlet from the rear end of the cylinder head could be increased with advantage. The pump delivery at low speeds is insufficient; at 500 RPM, on No. 1 unit the delivery was 18 lbs/min. with a temperature rise of 65oC. across the engine; No. 2 unit has a flow of 21 lbs/min. giving a temp. rise of 56oC. Phantom at 500 RPM, delivers 75 lbs/min. with a temp. rise of 13o. HS{Lord Ernest Hives - Chair}/L.H.Swindall. | ||