Normal
If you work it hard in the heat, yes, it will get hot and boil. First off, verify you are not too lean and replace the radiator cap. Also, the water pump shaft is a circle with 2 flat sides that fit inside the counter balancer. That shaft, along with the hole wears out, and actually won't turn the pump. A little by friction, but not enough to do any good. If all this checks out, go to like Steve said with the Engine Ice, or even Evans Waterless.