Drilling 1/8 hole in T Stat question

Turbo Keith

TURBO KEITH
Joined
Sep 16, 2015
I have heard that alot of folks do this to help in the flow , My old T stat was stuck open and the rad flowed great but when I replaced it with new 160 stat I could tell when it would warm up and open and close but now when it opens the flow is very slow . I have just removed the stat and bout to put it in water on the oven top and see if it opens and closes like it should but the question is about drilling the 1/8 hole and if I do does it matter at which position should the stat be put back in ? Thanks Keith
 
The small hole doesn't necessarily need to be 1/8". It is usually drilled in the disk & positioned at 12 o'clock. This provides a passage for coolant flow to prevent an air or steam bubble from becoming trapped.
 
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Keith, search is your friend, been discussed a lot over the years! ;)

search.jpg

First couple of results get you what you need:
https://www.turbobuick.com/threads/160-thermostat.415918/#post-3441435
https://www.turbobuick.com/threads/to-drill-or-not-to-drill-a-new-thermostat.422422/

Good luck.
 
Keith, search is your friend, been discussed a lot over the years! ;)

View attachment 303660
First couple of results get you what you need:
https://www.turbobuick.com/threads/160-thermostat.415918/#post-3441435
https://www.turbobuick.com/threads/to-drill-or-not-to-drill-a-new-thermostat.422422/

Good luck.
Not to hijack Keiths thread but after reading comments about "gutting" the stat or simply "removing" the stat, brings the question. Is there a downside to either of these comments? Since many of these are not daily drivers anymore, will the car run cooler with it gutted or removed? I go to local meets mostly and occasional out of town meets.
 
Running a T stat has more pros than cons and If it really needed a hole drilled in it, I would think it would come that way.
 
Running a T stat has more pros than cons and If it really needed a hole drilled in it, I would think it would come that way.
Did you mean running a t sat has more pros than cons ? I have always heard never run one without a T stat because the flow is so fast you never get a true temp reading , meaning one part of the engine is hotter than the other part of the engine
 
The small hole doesn't necessarily need to be 1/8". It is usually drilled in the disk & positioned at 12 o'clock. This provides a passage for coolant flow to prevent an air or steam bubble from becoming trapped.
+1 This quote should answer the OP's question. I drill a 3/32" hole. Back in the 90's, thermostats came with a bypass slot. The ones available today do not and have to be drilled. You can install it without as it is not necessary, but does have the benefits mentioned in above quote. Try not to overthink it......
 
Thanks for the advice guys , I will drill a small hole and place it at the 12 o clock position when I install the T stat . Keith
 
I remove the antifreeze and run water every year. I have found after 3-4 heat cycles (drive the car) all air is worked out. No drilling holes here.
 
I thought guys drilled the 1/8" hole in their 180 deg. thermostats to drop the temp to about 160 deg. because 160 deg. thermostats were not available for our cars in the beginning.

I am of the theory that when you are on top of Mt. Everest and you are cold, removing your clothes so the wind is in contact with your body for a shorter period of time (less restriction) will not make you warmer.
Maybe that's just me.
 
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Not to hijack Keiths thread but after reading comments about "gutting" the stat or simply "removing" the stat, brings the question. Is there a downside to either of these comments? Since many of these are not daily drivers anymore, will the car run cooler with it gutted or removed? I go to local meets mostly and occasional out of town meets.

I believe that with no T-stat the engine would take a very long time to get up to operating temp and be very inefficient, although reducing the chance of knock.
I also believe the converter will not lock up until the engine is up to 150 deg. or so.
 
Did you mean running a t sat has more pros than cons ? I have always heard never run one without a T stat because the flow is so fast you never get a true temp reading , meaning one part of the engine is hotter than the other part of the engine


Faster flow is always better, period. That's just basic physics.


A lot of people over the years (myself included) have ran without thermostats. When I had my crappy old clogged up radiator I needed all the flow I could get... and still ran hot.

With my fancy new super trick F Body radiator, I have to run a thermostat or the engine won't warm up at all unless I sit still forever. then it cools off as soon as I pull away.


Yes there is a a bypass hose on our cooling system. Its to keep the water pump out of cavitation while the thermostat is closed. Even when fully functional, it can't burp the air out of the very top of the intakes crossover passage. The steam hole will get most of it right out of the box.
 
Faster flow is always better, period. That's just basic physics.


A lot of people over the years (myself included) have ran without thermostats. When I had my crappy old clogged up radiator I needed all the flow I could get... and still ran hot.

With my fancy new super trick F Body radiator, I have to run a thermostat or the engine won't warm up at all unless I sit still forever. then it cools off as soon as I pull away.


Yes there is a a bypass hose on our cooling system. Its to keep the water pump out of cavitation while the thermostat is closed. Even when fully functional, it can't burp the air out of the very top of the intakes crossover passage. The steam hole will get most of it right out of the box.
So how about a gutted stat? Still not a good idea. At least the flow is slowed somewhat.
 
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