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).
Issues with car cooling systems, specifically radiator obstructions and hydraulic restrictions on S.S. versus V series models.
| Identifier | ExFiles\Box 15\1\ Scan143 | |
| Date | 21th August 1929 | |
| X 7250 To E.{Mr Elliott - Chief Engineer} from He/Rm.{William Robotham - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/MJ/21.8.29. X7250 X766 COOLING SYSTEMS. There are one or two facts in connection with the car cooling systems which have not been circulated. (1) The obstruction that blocks radiators always seems to collect in the top row of tubes. We are worse off with our top tube gap area to be blocked on the S.S. than we have been before. The length of top tube space on the S.S. is 25% less than it was on V series. The top water tank flange obstructs these tubes more than it used to. (2) on the S.S. radiator the hydraulic restriction across the matrix is, even with the 7/5½ mm. tubes, greater than on V series. (3) If there is a considerable depression on the suction side of a water pump, its delivery falls off very rapidly with increasing water temperature. Thus on the S.S. system with 7/6 mm. tubes, the circulation at high speeds with an inlet water temperature of 90°C. is only half that with an inlet temperature of 16°C. It will be seen that with the present epidemic of choked radiators, where the hydraulic restriction of the matrix is increased as much as five or six times, the circulation of the car virtually ceases even before the top water temperature reaches 100°C. | ||