The Stovebolt Site Forums The Shop Area Engine Shop Good thermostats?

This one had a hole in it as purchased, my father is pretty sure he drilled holes in all the ones he put in his truck (I also came across one he took out and it had a hole in it). Not enough to flow a meaningful amount of water, mind you, but plenty to let air out, which is the idea.

Alvin, the spike itself is slow building, temp just keeps climbing past 180 because it's not flowing any water. It's when it opens that it cools abruptly. Which is what I'm worried about, a 210-240 degree head getting hit with cool water every single time you drive it. My fathers truck also has vortec heads, which have a reputation for cracking. His truck will also seem to climb rapidly in temp somewhat, I presume because the heads don't have the bypass in them, and are getting locally hot, showing as an additional spike on the gauge when it starts flowing water.

No top/overflow tank, radiator is a brand new aluminum one. Wouldn't be the radiator anyway, only happens at warm-up.