The Stovebolt Site Forums The Shop Area Engine Shop Engine getting too hot before thermostat opens

Thanks Joe, I thought it was the spring that opened the T-stat. I've changed a few of them out, but been a while. Didn't realize the wax is the "mechanism". I'm almost there...just to be clear. So when cold engine is started, there is a temperature gradient in the engine...very hot, near the cylinder walls, and very cold up near the tstat. By drilling small holes (or allowing heater core/bypass volumes to circulate cold water out)in the tstat, it allows the cold water to move through the tstat and housing, so the hot water can get up there and open it up. The water temp sending unit is nearer the cylinder walls, and registers the hotter "core" block temps. As the cold water gets out of way, and hot water gets to the tstat (flowing vs. heat dissipation) it opens, and system equalizes.