CAVITATION—EROSION DAMAGE CONTROL IN ALUMINUM WATER PUMPS FOR CARS

Under high speed, high temperature driving conditions aluminum water pumps can be damaged by cavitation and/or erosion. Some antifreeze formulas increase the cavitation- erosion damage over that obtained with plain water. Therefore, selection of a compatible antifreeze is an important way of minimizing aluminum pump cavitation-erosion damage. Three laboratory tests are described which attempted to predict antifreeze cavitation-erosion performance in aluminum water pumps in cars in the field. Of the three tests, a high speed, high temperature laboratory pump test gave most reliable antifreeze performance prediction. A venturi apparatus gave results that correlated well with actual pump tests and showed promise as a screening tool for antifreeze evaluation, alloy selection, etc. A vibrator test fixture did not correlate well with pump tests.

Other means of reducing aluminum pump damage such as use of different aluminum alloys and reducing pump speed are also briefly discussed.