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

The temp sender is actually right under the thermostat. The temp increase after shutdown is due to heat soak from the hotter exhaust manifolds/heads/block, etc.

The radiator doesn't vent or boil, because in my case, all the heat is in the engine. This is right after starting from cold. Instead of warming up to 180, it overshoots to 210-220, then quickly drops back as the thermostat opens. The radiator is still cold while it's happening.

Anyway, I got my new thermostats in. Boiling them didn't instill great hope, so I drilled a hole big enough to flow water (1/8-3/16, can't remember) in one and put it in. I'll see if that works. Didn't seem to do it on the drive back, but the temp was still at 140 when I left, so it wasn't cold.

The old thermostat didn't work that great itself, although it didn't do this.