Cooling system overhaul -- how does this T-stat look?

[124Fan]

I'm replacing the timing belt + water pump on my '77. All of the radiator hoses had significant swelling and coolant had leaked past most of the clamps. Several of them were so badly corroded that they could not be unscrewed (long bolt-style clamps) and had to be cut off.

This is a Savara thermostat. I was looking at the IAP document on drilling a hole in the plate area for the bottom radiator hose. That does not appear to be possible or needed for this t-stat?

Lower hose outlet at room temperature:


Upper hose outlet at room temperature:


Lower hose outlet in ~190F water:


My conclusion based on this testing is that this T-stat is ok and requires no drilling.

Sonny

[courtenay]

Drilling a hole has nothing to do with the operation of the t-stat and everything to do (some advocate) with the ability to burp the cooling system. If your t-stat is opening at the correct temperature, it is fine. If you burp the system properly you don't need to drill a hole in the t-stat. I have the same t-stat that you have. I haven't drilled it. I have drained, filled and burped my cooling system and everything works just fine, thank you.

[So Cal Mark]

someone has already drilled that one, and the hole is so large it will render the stat fairly worthless.

[124Fan]

You're right, Mark. It has been drilled! I looked at it more closely and can see the tooling marks. It's a big hole, too...just measured and a 3/8" bit fits perfect.

I'll get a new one. I was fairly convinced that a lot of this car was original and untouched. Makes me wonder what else has been "fixed".

Thanks!

Sonny

[So Cal Mark]

I generally don't drill a hole any larger than 1/8", just enough to bleed the air out, not so large the stat is bypassed

[majicwrench]

I am not a fan of drilling holes, it was designed to work without a hole. I have seen cars that would never get up to temp even with small (1/8") holes.
BTW, Fiats are not the only ones that get "drilled" I have seen all sorts of thermostats with small hole moused into them.
Keith