[george kujanski]

Aronhk: I agree that it would be a good idea to summarize the various points brought up in this thread and others in the heating/cooling forum over the last few years.

Perhaps I may do that.

A recent thread also describes another interesting point. Apparently some factory cars, especilly those with AC, also used a smaller diameter water pump pulley whic increases the fan and pump speed. Several members have changed their pulleys and achieved a reduction in engine temps.

Your idea of adjusting the impellar position has merit, and probably the OEM pumps were set up correctly. My opinion is the rebuilders may not have been aware of what the proper dimensions should be so we end up with the variations that we see today.

When I first investigated mine, a hammer seemed to be the easiest way to experiment with since I don't have a press.

George