Drilling Holes In Thermostats

[toobroketoretire]

In another forum I have seen many people recommend drilling two small holes in C3 thermostats so the engine can be filled with coolant a little bit faster. I had never drilled holes in any of my C3 thermostats so when I saw it mentioned in C3 forums I got to wondering what those holes accomplished. So a couple of years ago during the winter I drilled two 3/32" holes in my thermostat and found I had to drive triple the distance before my heater began blowing hot air. Those two little 3/32" holes allowed so much coolant thru the thermostat (and radiator) my engine refused to warm up in anywhere near the usual time. I found I could fill my engine with coolant about 5 minutes faster but as I'm in no hurry I felt the tiny gain wasn't worth the delayed warm up time.

My professional opinion? C3 thermostats don't need any holes drilled in them!

 

[dougelam]

This is where the mods revoke TBTR's membership!
After all the shit he posted he has the nerve to cut down a valid tip

[emoji107]

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[toobroketoretire]

This is where the mods revoke TBTR's membership!
After all the shit he posted he has the nerve to cut down a valid tip

[emoji107]

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You made my day. When I read your response I busted out laughing. When it comes to ridiculous C3 myths drilling holes in thermostats has got to be one of the stupidest.

 

[dougelam]

It's not a C3 myth, you made it a C3 myth
It is used in other engines with positive results!

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[toobroketoretire]

Darwin Award

It's not a C3 myth, you made it a C3 myth
It is used in other engines with positive results!

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So you're claiming a C3 engine having to run three times the distance before warming up is a POSITIVE result? Please remember we're in a C3 forum talking about C3 thermostats and not uh "other" engines. You really need to make a serious effort to comprehend what you read before you earn a Darwin award and natural selection removes you from the gene pool.

 

[dougelam]

So you're claiming a C3 engine having to run three times the distance before warming up is a POSITIVE result? Please remember we're in a C3 forum talking about C3 thermostats and not uh "other" engines. You really need to make a serious effort to comprehend what you read before you earn a Darwin award and natural selection removes you from the gene pool.

You brought it up buddy not us
And no, YOU are claiming it takes 3 times as long too warm up in which I am calling bullshit

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[Antz81]

So you're claiming a C3 engine having to run three times the distance before warming up is a POSITIVE result? Please remember we're in a C3 forum talking about C3 thermostats and not uh "other" engines. You really need to make a serious effort to comprehend what you read before you earn a Darwin award and natural selection removes you from the gene pool.

1 if anyone here will earn a Darwin Award it will be you.

2 an engine is an engine it doesn't matter what it is in.

3 your car will always take longer to warm up when you have the heater on.

4 you are probably the only person that drives their c3 in winter.

that being said I don't think there is any need to drill holes in a thermostat.

 

[toobroketoretire]

Another Darwin Award Nominee

You brought it up buddy not us
And no, YOU are claiming it takes 3 times as long too warm up in which I am calling bullshit

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You really need to re-read what I wrote and comprehend what you read. With a stock (not drilled) 195 degree thermostat and a 20 degree outside temperature my heater would begin blowing warm air within about 5 downhill miles. After drilling two 3/32" holes in my thermostat I had to drive about 15 downhill miles before it began blowing warm air. So why three times the distance? Because those two 3/32" holes were allowing enough coolant to pass thru the thermostat to prevent my engine from warming up to operating temperature. To be effective a thermostat in an ice cold engine has to STOP the coolant from flowing thru it; not ALLOW coolant to flow thru it. As I live in the mountains my engine is literally coasting for the first 15 downhill miles so it's not working hard enough to produce much heat. If I had to drive UPHILL it would warm up in 1/4 the time.

According to the forum uh "experts" the whole purpose of the holes is to allow a quicker fill-up time when filling a dry system. But heck, are we REALLY in that big of a hurry? And how often do we deal with dry systems? I pour my coolant into my radiator until it's full. Then I do something else for a few minutes then add more coolant until it's full. Then I do something else for a few minutes then add more coolant until it's full and once I find it's staying full I'm done. Big whoopie. So it took me 5 minutes longer once every two YEARS.

In another forum I actually read a member would take his thermostat housing off then force his thermostat open and wedge an aspirin in it (holding it open). Then reinstall the thermostat housing and begin filling his system. With the aspirin holding his thermostat open he was able to fill it faster. Heck, in the 5 minutes it took him to put the aspirin in he could have filled it twice. He definitely is eligible for the Darwin Award for stupidity.

 

[dougelam]

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[toobroketoretire]

It's All Downhill From Here

When I leave my home and head to the valley below it's almost all downhill. So my engine runs around 1500 rpm under virtually no load with the exception of a couple of half mile long hills. As such my engine is very slow to warm and a thermostat with holes in it makes it even slower to warm...............like three times slower on 20 degree mornings. As the whole purpose of holes is to reduce the filling time of a dry system I'd much rather have quicker heat than a faster fill time every two YEARS.

Is the "need" for holes in thermostats just another ridiculous C3 myth? Yep.

 

[dougelam]

The holes isn't the issue, it wasn't a C3 myth until you said It was!

1 person did it and made mention of it in another forum, how does this make it a myth?

Your are the one whom regurgitated it

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[Antz81]

He definitely is eligible for the Darwin Award for stupidity.

I don't think you know what a darwin award is.

 

[toobroketoretire]

The holes isn't the issue, it wasn't a C3 myth until you said It was!

1 person did it and made mention of it in another forum, how does this make it a myth?

Your are the one whom regurgitated it

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The "myth" is the continued assertion it's a NEEDED modification. Uh, needed for what? To be able to fill it faster? Heck, if filling it in record breaking time is the goal then just loosen the thermostat housing bolts so air can escape. Once it's full then tighten the thermostat housing bolts and you're good to go. But why ruin a good thermostat just for the sake of filling it faster? With retarded reasoning like that we might as well run one quart of oil in our engines so it can be drained faster during oil changes. Or fill our gas tanks 1/4 full so we don't waste so much time at the gas pumps. When it comes to goofy ideas NOBODY beats C3 owners.

I changed my 85W140 rear axle lube yesterday afternoon then took a drive to my mailbox on the side of the highway. If I had listened to C3 forum members I should have found a big parking lot first and run some figure 8's to uh "work the new lube in". The "need" for running figure 8's after a rear axle lube change is another one of the ridiculous C3 myths that have been around for many years. Like the "need" to adjust hydraulic lifters with the engine hot and running, and the "need" to shim distributors, and the "need" to index spark plugs, and the "need" to run balloon tires at rock hard pressures, and the "need" to run enormous mechanical secondary carburetors on street engines, and the "need" to pre-fill oil filters, and the "need' to use lighter aluminum parts when we have a 350# wife sitting on the passenger seat.

 

[LLC5]

When it comes to goofy ideas NOBODY beats C3 owners.

You do realize that you are of course a multiple C3 owner?

So, in reference to you, I do agree.

NOBODY beats you for ridiculously stupid and goofy ideas.

 

[dougelam]

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[SVO]

I drill my thermostats with a single hole as I believe it helps burp the system of any air trapped in the block when changing out the coolant. There is one brand of thermostats, Robertshaw?, that sells a thermostat already with the hole pre-drilled.

 

[toobroketoretire]

Air Pockets? What Air Pockets?

I drill my thermostats with a single hole as I believe it helps burp the system of any air trapped in the block when changing out the coolant. There is one brand of thermostats, Robertshaw?, that sells a thermostat already with the hole pre-drilled.

First of all the Chevrolet V8's don't have any "air pockets" and that is just another one of the many C3 myths that owners have kept alive. If the thermostats really needed holes in them the thermostat manufacturers would have put them in back in the mid 1950's when the 265" engines came out. All holes accomplish is delaying the warm up time a lot in the cold winter months. If you look closely at any OEM thermostat you'll see a tiny "notch" in the edge of the 1" hole where the center valve seals. That little notch allows a LOT of air to pass thru the thermostat without really affecting the operation of the thermostat and it does the "burping" for you. Cool, huh?

 

[stevolwevol]

First of all the Chevrolet V8's don't have any "air pockets" and that is just another one of the many C3 myths that owners have kept alive. If the thermostats really needed holes in them the thermostat manufacturers would have put them in back in the mid 1950's when the 265" engines came out. All holes accomplish is delaying the warm up time a lot in the cold winter months. If you look closely at any OEM thermostat you'll see a tiny "notch" in the edge of the 1" hole where the center valve seals. That little notch allows a LOT of air to pass thru the thermostat without really affecting the operation of the thermostat and it does the "burping" for you. Cool, huh?

TBTR, I had a problem when I replaced my intake gasket on my 92 Camaro. It had an air pocket big time. The thermostat wouldn't open at all. I removed the thermostat, and it didn't overheat. When I put it back in it overheated. I had a mechanic use a suction device to suck the air pocket out. Maybe a thermostat w/ a hole drilled in it would have solved my problem, but this took care of it. This is the only time this has happened to me, and I still don't fully understand why, but it did. Air pockets in Chevy small block intakes DO exist.

 

[kpic]

https://www.google.com/search?q=chevy+thermostats&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjx1Ka6gLvQAhWc14MKHSLkAswQ_AUICSgC&biw=1083&bih=567#tbm=isch&q=drilling+holes+in+chevy+thermostats

These holes???

 

[toobroketoretire]

Air pockets in Chevy small block intakes DO exist.

A Chevrolet V8? The water passage on a Chevrolet V8 intake manifold goes straight thru from side to side with no place air can become trapped. As the thermostat has a little "bleed notch" air passes thru that notch. As the notch is small it does take a few minutes for the air to pass thru but it's certainly not an "air pocket" by any definition. I have been building Chevrolet V8's for 50+ years and I have never known of any air pockets to exist. If they do exist please tell me where. Now, there is the possibility the little holes in your head gasket had become plugged with rust or other debris and that would slow down the flow of coolant from the block into the heads when you filled it.