Which Thermostat should I use

catterar

catterar

Bob Cattera
As part of the rebuild of my engine I thought it would be best to replace the thermostat. The car is an ’81 FI with AC.
I bought a new stat from vendor A. When I disassembled the thermostat housing I found that the new stat was shorter than the old stat.
I needed to order some items from vendor B that vendor A did not have in stock. So I decided to just order another stat from vendor B at the same time.
That stat arrived today and it was also shorter than the existing stat.
So what I have is an unknown stat that is 1.32 inches from seating surface to seating surface that touches both seating surfaces of the thermostat housing. A Whaler stat that is 1.22 inches from seating surface to seating surface. A Stant stat that is 1.22 inches from seating surface to seating surface.
My question is which stat should I install? The old one that was working well before the rebuild or one of the new stats?

Thanks,
 
Bob... I know NOT the measurements...

But I used a Stant p/n 45378 dual action stat... and it works PERFECTLY!

Whatever stat you choose, it MUST be the dual action type, as the single action stat will negate the entire cooling system DESIGNED operation.

HTH...
 
I just made this decision....I decided to stick with the OEM Savara stat. To me it's obvious that the OEM unit fits in the housing much better and has a much larger opening thru which the coolant flows, and it looks better made, too.

Too bad I spent over $30 buying that same Stant stat from one of the vendors, not realizing that I could have bought the same cheesy stat for less than half that in a local AdvancePepZone.

Here's an album of pix from my stat tests:
http://s14.photobucket.com/albums/a341/DSarandrea/tstat/
 
T-stat

Tony and Dan,
Thanks for your comments and Dan thanks for the Photos. I have decided to reuse the existing thermostat. Tony all three t-stats are dual action the stant is a 13378 from vendor B.
 
Bob, Dan... take a minute and read...

... my Thermostat 102 blog...

http://www.network54.com/Forum/12159/message/1131515511/THERMOSTAT+102

This was 5 years ago or so... HA!

Note some of my LEARNINGS...

I found, in my case... that the stat was not closing fast enough or thoroughly enough and NOT allowing the coolant to COOL DOWN in the radiator. In other words, too much flow!

The fotos are gone, but this was caused bu a compromised gasket... and a tired spring.

I BELIEVE that the springs "fatigue" over time and can also be "overstressed" if over heated a time or two... and then therefore not perform correctly.

So I say all his Bob... to say your old stat may just be fine if it was never overstressed... at least for awhile, but age does play a factor.

And Dan, I remember the days when we tossed the stats outta Flathead Fords so the coolant would continually circulate... as these engines were notorious for overheating. Worked great for awhile... but when it did get hot, it continued to get hotter and hotter! HA!

Worked great for our 3 mile trip to school or street racing... but we were generally found on the side of the road boiling over on a 25 mile trip to the beach! HA!

Good chatting with you guys... and Bob... you can always roll those stats pretty easily... Let us know how ya do... and don't forget to COVER that stupid little hole on the stat housing with the proper gasket!
 
my solution

find a decent metal fabricator and ditch that dual action crap thermostat housing for a housing that will hold a chevy 350 - 180 degree thermostat, and bypass the other hoses so the water circulates like every other vehicle in the world- you know the ones that don't run hot. Cant wait to do this and prove I'm right.
 
The only time Ive had a problem with the stock system is when my rad was toast otherwise the stock system works well for me. I guess living in Canada helps too!:)
 
in a perfect world

we would all live in a climate made for the X, but yeah down here in Texas - need all the help I can get, in spring and fall all is good, but when the heat index is 108, better not have a darn thing wrong- kinda hard on a 30 year old car. Can't stand having a car that will overheat so badly if you get a pin leak, and I really think it's due to that dual action thermostat, which is primarily designed for a quick warm up- which we really don't need down in my part of the world
 
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