Racing Water Pumps - Pump It Up

If you read the "Turning Dirt to Asphalt" story written by Rob in this issue, you saw a little part that talked about the water temperature in our engine. Ever since we owned this car the water ran 180-190 degrees, ideal temperature range. This season that changed. It started off slowly, what used to be 180-190 turned into 190-200. Then 200-210. Well, after all the testing and practice at Charlotte County we were staring at 240...never a good thing. An engine running 240 has the potential of leaving a mark...all over the track.

Was there something wrong with the brand-new radiator?

Was a hose collapsed?

I wasn't sure, but let me make one thing clear, at speed, the motor never ran that hot, it was only after I slowed down or pulled into the pits that the temp climbed and the engine started puking water out of the overflow hose.

This made me especially concerned because the Charlotte County race was on pavement and everybody told me that the car would run hotter on asphalt. Plus, putting all these dirt drivers on pavement for the first time, we were going to have a bunch of cautions. I could just see the temperature gauge climb through the roof during a yellow. By the way, if you did read "Turning Dirt to Asphalt" then you already know I was concerned about the cautions for nothing.

Anyhow, after qualifying, we took some time out to check out the engine. With the motor running we could see a faint wobble in the fan. By the time the 50-lap race was over, the wobble was a bit more noticeable. It was becoming clear that the water pump was on its way out. Not wanting to risk a major engine problem, we chose not to ignore the pump issue and as soon as we got back from Charlotte County we began hunting water pumps.

There aren't any rules governing water pumps in our series so the field is wide open. Now, you can spend anywhere from $50 to $320 on a water pump. But this story is all about choosing the right water pump.

Before we get into actually making our choice, let's do a little water pump review. Not to insult anybody's intelligence, but water pumps are a critical component of a race engine. If you think of the water running through the motor as its blood, then the water pump is its heart. There are several critical areas of a water pump such as the internal passages, the impeller and the seals. When choosing a water pump, you need to look at each of these areas as well as the hub, bearing and gaskets.

However, as important as the physical design of the pump and the quality of components used in it, is the rest of the cooling system. Items such as the fan, radiator, pulleys and hoses work together with your water pump to keep your engine cool. Believe it or not, it's possible to pump the water through the motor so fast that it won't do a good job of cooling, which is why some people run restrictors in the radiator. That is, however, the subject of another story. The point here is choosing the right water pump is about matching it to your whole cooling system.