For What Its Worth
Stewart Stage 2 Water Pump
Stewart Stage 2 Water Pump
I put in a Stewart Stage 2 water pump. There is a noticeable difference. My temp gauge is located in the passenger side head, toward the rear of the engine. It would run 185-190 most of the time before. With the Stewart pump it now runs 175-180 most of the time. Thermostat is the same and the fans work as they always did. The pump is pushing the water through at a better rate, even to the rear of the engine. More consistent temp and cooling. Could this translate to more advance? I will have to think about it.
Bolt warning. Make sure the fan bolts DO NOT bottom out on the pump bearing or housing. The Stewart stage 2 pump has the cast bearing support and bearing close to the hub. Not the big space like the stock pumps. If the bolts protrude out of the backside of the hub they could tear up the front of the pump. I am running a pulley only. I had to get 5/16-24 3/4 inch long bolts. (Not many places carry the grade 8). With lock washer and a washer it was still close in my case. I added a second lock washer. Test fit the bolts without the fan belts on and make sure they don't hit and the hub spins free.
This is a picture of a typical stock pump shaft. The large space behind the hub does not exist on the Stewart pump. Also the cast hub on the Stewart is a larger diameter.
