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).
Investigation into cylinder water jacket pressures on Kestrel 'carb in Vee' engines with evaporative cooling systems.
| Identifier | ExFiles\Box 179\3\ img031 | |
| Date | 1st March 1932 | |
| Copy R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Glb. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Lr.{Mr Ellor} c. to By.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} c. to Mr. Jaques. K2965 K2444 Hs{Lord Ernest Hives - Chair}/Glb.4/MA.4. 3. 32. KESTREL ENGINES. CARB IN VEE EVAPORATIVE COOLING. CYL' WATER JACKET PRESSURE INVESTIGATION. Tests have been made to investigate the pressures in the cylinder water jackets of the "carb in the Vee" Kestrel engines on similar lines as those made on the s/c engine water system, when it was found necessary to enlarge the top water pipes in order to reduce the cyl block pressures, and as a result of the tests modifications are necessary on the "carb in the Vee" engines. The difference in the top water pipe arrangement on the s/c and carb in Vee engines is that on the former type each bank of cyls have a separate top water pipe whereas with the carb in Vee engine the top water pipe is common to both banks of cyls. The tests on the carb in Vee engine revealed the cyl block pressure to be high and left very little margin for the water pump (which is the latest type for evap cooling) to overcome the possibility of a reversal of flow. It was also found that the pressure in the main top water pipe was high at the front (propeller end) also high at a point just in front of where the rear outlets from the cyl blocks join the main pipe and then there was a sudden drop in pressure just behind these rear outlets at a point where the header tank connection is made. This is due to the position of the rear outlets joining the main pipe on the same circumference and the water from each converging thus producing the high pressure. On the s/c engine the rear outlet elbows have a nice sweep toward the rear which would not affect the rail pressure at the point of entry. METHOD ADOPTED FOR REDUCING THE PRESSURES. The pressure in the cyl blocks were reduced and made comparable with those on the s/c engine by fitting an extra pipe (3/4" dia) from the front end of each block, (using a union in place of a core plug,) and taking it direct to the header tank. The back pressure in the main pipe referred to in the previous paragraph was reduced by taking the rear outlets direct to the tank also. The attached chart shows the results step by step and the sketch, the layout of the top water pipes. | ||