Chevy Corvair Thermostats

We get all kinds of questions about thermostats and flaps... maybe you are wondering:

It does not get cold where I live, or I only drive in the summer. Do I really need to run thermostat
flaps?


Would you take the thermostat out of your Ford, your Toyota? no? then why take it out of your Corvair? The Corvair thermostat does not even begin to open until 200F, it is certainly not that hot outside!

The point of the thermostat is not to provide cooling. The thermostats are there to get the engine heated up to proper operating temperature as fast as possible and then maintain
that temperature.
 This is the #1 misconception about the thermostat system. Everyone thinks they are meant to keep the engine cool, when it really is meant to heat it up quickly. But NO, you are not required to run the thermostats. Many Corvairs are running all over the world, in all sorts of temperatures and conditions with the thermostats missing. However, all of those engines are running too cold at startup. This means that all of those engines have lower fuel economy (less MPG), more engine wear, and resulting shorter engine life. So, if you are not
concerned about those things, you don't need thermostats.

Can the thermostat doors get stuck closed, causing the engine to overheat?
Nothing is impossible, so yes, they could get rusted closed or hung up in the closed position, which would result in an overheated engine. However, this is very unlikely. With a fresh blasting and powdercoat, you should be fine for many years to come.

Can the thermostat iteself get stuck closed, causing the engine to overheat?
The thermostats are designed to be fail safe, meaning that if they fail, they SHOULD fail in the full open position, giving you maximum cooling. I have seen 100's of thermostats over the years, and I have only seen three used stats that were contracted that did not expand when heated. So it is possible, but it is not very likely.

How does the thermostat work anyway?
The units have a small amount of liquid inside that expands when heated. The bellows are held closed by the partial vacuum inside the sealed unit. As the stat is heated, the liquid
vaporizes and the bellows expands. When the stat cools off, the vapor returns to liquid and the bellows contracts. If the liquid ever leaks out, the bellows will expand, causing the doors to go full
open. This is why the stats are considered fail safe.

At what temperature does the thermostat open?
It depends on which thermostat you have:

The corvair stats are designed to open at 200F, full open is at 230F.

My engine oil temperature is X, so should the doors be open now?
Both the engine oil temperature and the temperature of the air coming off the cylinders are due to the heat generated by the engine running. But there is not a direct connection. Don't try and use one to determine the other.

I drove the car for five minutes and the doors are not open yet. What is wrong?
The doors are still closed because the engine has not heated up yet. The minimum temperature the thermostat has to see is 200F - it just has not gotten that hot yet.

Can I run a bug thermostat on my corvair engine? They look similar.
The Corvair stat opens at 200F, the bug stats open at lower temps, The fittings on both ends are also wrong. You would have to make some sort of adapter. not recommended
 

Our Corvair Thermostat Bellows

Stock design has seveal flaws, leading to shorter thermostat life.

Awesome Powdercoat thermostat has an improved design, smooth 1 piece bellows, internal stop and a two year warranty.

No one can match it.


INSTALLATION TIP - Looking at how the stat is installed in the lower shroud,,,,, you can see the rod has a special fitting on 1 end that goes into the arm on the damper door, it also has a special lock down catch, the stat itself is not the easiest part to install into the bracket, you have to install the long end 1st, then twist in the short end. The hole in the bracket is slotted, so that the thermostat can not rotate once installed. note that when closed, the damper door is still about 1/4" open at the top, you do not want it completely closed off, when you shut the damper, you can pull the rod back and see how much you need to thread it into the stat. turn the stat to thread it onto the rod, check how closed it is,, once good, install the nut on the end of the stat, now you are ready to onto the engine.
Corvair stat

TWO corvair thermostats

Model: Chevy Corvair
Engine: flat 6
Warranty: Yes, 2 years
(discounted price for buying 2)
ONLY $180
 
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Corvair stat

ONE corvair thermostat

Model: Chevy Corvair
Engine: flat 6
Warranty: Yes, 2 years

ONLY $99
 
Review and Purchase