Tired of junk thermostats. Going with NOS. Do I need to drill a hole in in?

-
All this talk about drilling a hole. I have done many thermostat's (including several Slants) and never had a problem. Just did one about a week ago on my 360 and no issues???
Exactly. 90% of the time there is no issue. The first time firing a newly rebuild can get some air pockets. Just changing out stats isn't an issue.
 
All this talk about drilling a hole. I have done many thermostat's (including several Slants) and never had a problem. Just did one about a week ago on my 360 and no issues???
Most times you don't. There's always one. lol
 

This summer my '64 Dart slant six was over heating on hot days. The local radiator shop suggested to get the radiator cleaned and rodded. I decided to wait until winter because he was very busy. He is a good radiator guy and has worked on a few of my old cars over the years.

I fooled around with it during the Summer. I ran some cleaner for about 500 miles and had it back flushed. Things improved a lot but the engine tempo was varing alot. I bought and installed a new 180 thermostat, with the the erratic results. I pulled that termo and bought and installed a more expensive one. No change.

I'm kind of hardheaded, and installed a FlowKooler Robertshaw 180 330 series thermo.

Bingo!

Thermo guage right on. To make sure, I used my laser temp. reader on the radiator top and btm hose connectors and readings showed the raditor seems to be cooling the water as it should.

Around 170 going in and 145 to the engine.

I'm forced to conclude that 2 new thermostats were defective and the Robershaw worked as it should.

Has anyone else experienced disappointment with junk thermostats?
Any good results with the Robertshaw FlowKooler?

I'll see if these good results continue when hot weather arrives next summer and post results.

Steve
 
This summer my '64 Dart slant six was over heating on hot days. The local radiator shop suggested to get the radiator cleaned and rodded. I decided to wait until winter because he was very busy. He is a good radiator guy and has worked on a few of my old cars over the years.

I fooled around with it during the Summer. I ran some cleaner for about 500 miles and had it back flushed. Things improved a lot but the engine tempo was varing alot. I bought and installed a new 180 thermostat, with the the erratic results. I pulled that termo and bought and installed a more expensive one. No change.

I'm kind of hardheaded, and installed a FlowKooler Robertshaw 180 330 series thermo.

Bingo!

Thermo guage right on. To make sure, I used my laser temp. reader on the radiator top and btm hose connectors and readings showed the raditor seems to be cooling the water as it should.

Around 170 going in and 145 to the engine.

I'm forced to conclude that 2 new thermostats were defective and the Robershaw worked as it should.

Has anyone else experienced disappointment with junk thermostats?
Any good results with the Robertshaw FlowKooler?

I'll see if these good results continue when hot weather arrives next summer and post results.

Steve
Like stated previously, test everyone in a pot of water on the stove with a thermometer before installing.
 
I installed a 180* Stewart high flow t stat and it worked perfect all summer...180* on the nose. Went for a fall cruise at 0*c / 32*f and the car ran stone cold. An hour of driving on the highway barely got it over 160*. Not sure what is going on? Maybe stuck open?

I have an Autometer mechanical temp gauge with the sender mounted in the T-stat neck.
 
I installed a 180* Stewart high flow t stat and it worked perfect all summer...180* on the nose.

Remember, the thermostat sets the minimum operating temperature, not the maximum.

Went for a fall cruise at 0*c / 32*f and the car ran stone cold. An hour of driving on the highway barely got it over 160*. Not sure what is going on? Maybe stuck open?

Yup.
 
I have a Lisle brand spill free funnel that you fill the system with, let it run and the air will bubble it's way out of the system. Also, not cheap, but there are cooling system vac's that pull all the air out and then the suction draws coolant in. No air in the system. The small hole in the stat and let it run with the cap off is the cheapest and works well. Like mentioned before. Test every t stat before installing it. Many/most new ones don't work, right out of the box.

View attachment 1716481461

On my 360 I used this and had the car on a slanted driveway after a water pump replacement. My thermostat came with a small hole already. I filled the funnel about 1/4 of the way and ran the engine. I had to add some coolant a few times. Be careful because you can get some burping and overflowing. After a couple of minutes of the car running all the burping went away. Really nice tool to have.
 
I'm odd.... I grab a the basic stant, drill a small hole, fill er' up, and a way we go.... I laugh when folks say "that hole is a touch to big"... Like the small hole is enough flow to cool an engine without the stat opening... LOL If that's the case, then I will give you a thermostat block off plate and drill a small hole in the middle and your car should cool just fine... :)

What size hole is that that you drilled?
 
After trying 3 different thermostats, I tried a FlowKooler Robertshaw 180 330 series with a seven lb. radiator cap and everything is working well. Go figure?
I'm sure results will vary, having owned numerous 60 year old slants in the past. (LOL)!
 
I'm odd.... I grab a the basic stant, drill a small hole, fill er' up, and a way we go.... I laugh when folks say "that hole is a touch to big"... Like the small hole is enough flow to cool an engine without the stat opening... LOL If that's the case, then I will give you a thermostat block off plate and drill a small hole in the middle and your car should cool just fine... :)

The theory of operation for a thermostat is to heat (not cool ) the engine when the thermostat is closed. The small hole, notch or jiggle pin aids in bleeding air to prevent an air pocket from forming around the thermo element or wax pallet when filling the system and during opperation. That is why thermostats mounted vertically should have the notch, hole or jiggle pin mounted in the 12 o'clock position. Most systems will also have a bleed plug or valve near the top the thermostat housing ( thermo element or wax pallet side) to be opened or removed to bleed the system on a refill of the system. Any plug, a temp sender or a hose adjacent to the thermostat will work to bleed the air on a refill. If relying solely on the notch, bleed hole or jiggle pin then add coolant slowly when refilling. All the air trapped in the system will have to pass through the small orifice.
Drilling a hole in the thermostat will slow down how quickly the engine warms up. The warm up delay will be proportional to the size of the hole drilled. Too big of a hole and at cold temperatures this can result in poor heater performance. Drilling a hole will not prevent a motor from overheating if the thermostat is stuck shut.
One application where there may be advantages to drilling a larger hole in a thermostat is in racing. 1. No heater in play. 2. Alows a faster refill of the system without fear of trapping air when not using a bleed plug or bleed valve. 3. While it is still a slower warm up compared to not drilling, it is a faster warm up than a restrictor washer or no thermostat at all.
 
The theory of operation for a thermostat is to heat (not cool ) the engine when the thermostat is closed. The small hole, notch or jiggle pin aids in bleeding air to prevent an air pocket from forming around the thermo element or wax pallet when filling the system and during opperation. That is why thermostats mounted vertically should have the notch, hole or jiggle pin mounted in the 12 o'clock position. Most systems will also have a bleed plug or valve near the top the thermostat housing ( thermo element or wax pallet side) to be opened or removed to bleed the system on a refill of the system. Any plug, a temp sender or a hose adjacent to the thermostat will work to bleed the air on a refill. If relying solely on the notch, bleed hole or jiggle pin then add coolant slowly when refilling. All the air trapped in the system will have to pass through the small orifice.
Drilling a hole in the thermostat will slow down how quickly the engine warms up. The warm up delay will be proportional to the size of the hole drilled. Too big of a hole and at cold temperatures this can result in poor heater performance. Drilling a hole will not prevent a motor from overheating if the thermostat is stuck shut.
One application where there may be advantages to drilling a larger hole in a thermostat is in racing. 1. No heater in play. 2. Alows a faster refill of the system without fear of trapping air when not using a bleed plug or bleed valve. 3. While it is still a slower warm up compared to not drilling, it is a faster warm up than a restrictor washer or no thermostat at all.
I’ve had zero issues with what you mentioned. Each person does what they do, whatever works for them.
 
I’ve had zero issues with what you mentioned. Each person does what they do, whatever works for them.
How did you do that? Make a post disappear and then replace it with another.
 
How did you do that? Make a post disappear and then replace it with another.
I hit the delete button underneath the post. I just seen my post as leading to a bunch of this and that so I just got rid of it.
 
I hit the delete button underneath the post. I just seen my post as leading to a bunch of this and that so I just got rid of it.
Sometimes it helps to count to ten first.
 
I didn’t say anything wrong. Just wasn’t gonna leave the door open lol. Anymore I’m not here to change minds I just state what I do.
Must have excited you judging from all the exclamation points. lol
 
Must have excited you judging from all the exclamation points. lol
that was what others have said... in all out alarm! LOL Read the comments under that short I made, hilarious
 
The theory of operation for a thermostat is to heat (not cool ) the engine when the thermostat is closed. The small hole, notch or jiggle pin aids in bleeding air to prevent an air pocket from forming around the thermo element or wax pallet when filling the system and during opperation. That is why thermostats mounted vertically should have the notch, hole or jiggle pin mounted in the 12 o'clock position. Most systems will also have a bleed plug or valve near the top the thermostat housing ( thermo element or wax pallet side) to be opened or removed to bleed the system on a refill of the system. Any plug, a temp sender or a hose adjacent to the thermostat will work to bleed the air on a refill. If relying solely on the notch, bleed hole or jiggle pin then add coolant slowly when refilling. All the air trapped in the system will have to pass through the small orifice.
Drilling a hole in the thermostat will slow down how quickly the engine warms up. The warm up delay will be proportional to the size of the hole drilled. Too big of a hole and at cold temperatures this can result in poor heater performance. Drilling a hole will not prevent a motor from overheating if the thermostat is stuck shut.
One application where there may be advantages to drilling a larger hole in a thermostat is in racing. 1. No heater in play. 2. Alows a faster refill of the system without fear of trapping air when not using a bleed plug or bleed valve. 3. While it is still a slower warm up compared to not drilling, it is a faster warm up than a restrictor washer or no thermostat at all.
Do You see the weather where Tim is??? Do You have any idea how many 2.2/2.5 Mopars I've worked on from 1985 to present professionally? I own 7 currently & Pop owns 2, both Turbo II's, and they were My primary/daily transportation until 10yrs ago when I bought the '06 'rolla.
All this taking more time to heat up as an issue is proportional to the stupidity level of the operator, don't drill a freaking 1/4" hole in the thermostat, air doesn't need much room to bleed right out. 2.2's were notorious for not bleeding trapped air, if the hex socket pipe plug(top of housing part of head) came out it was easy to solve, if it was turbo'd one could get lucky sometimes & crack the coolant supply tube at the same section & get a lot of it out.
I watched a lot of them get cooked by 'waiting for the thermostat to burp', lolol, the air unfortunately blocks the water level from reaching the wax enough soon enough AND from the temp sender. By the time the head is so smoking hot (212°) to turn the fan on, still not full of water, it's too late & the thermostat still hasn't opened. So guys shut it off & then it starts gurgling & boiling right around an inch above the head gasket, then they try again,.....etc. etc.
A 1/16"-3/32" hole is not going to create a significant warm-up issue, & will solve all the f'd up drama above, and......better yet, when the thermo does finally open, some of that trickle of warmed-up antifreeze will have the rad temp better than -5°F....less temp-shock is a good thing.
 
Do You see the weather where Tim is??? Do You have any idea how many 2.2/2.5 Mopars I've worked on from 1985 to present professionally? I own 7 currently & Pop owns 2, both Turbo II's, and they were My primary/daily transportation until 10yrs ago when I bought the '06 'rolla.
All this taking more time to heat up as an issue is proportional to the stupidity level of the operator, don't drill a freaking 1/4" hole in the thermostat, air doesn't need much room to bleed right out. 2.2's were notorious for not bleeding trapped air, if the hex socket pipe plug(top of housing part of head) came out it was easy to solve, if it was turbo'd one could get lucky sometimes & crack the coolant supply tube at the same section & get a lot of it out.
I watched a lot of them get cooked by 'waiting for the thermostat to burp', lolol, the air unfortunately blocks the water level from reaching the wax enough soon enough AND from the temp sender. By the time the head is so smoking hot (212°) to turn the fan on, still not full of water, it's too late & the thermostat still hasn't opened. So guys shut it off & then it starts gurgling & boiling right around an inch above the head gasket, then they try again,.....etc. etc.
A 1/16"-3/32" hole is not going to create a significant warm-up issue, & will solve all the f'd up drama above, and......better yet, when the thermo does finally open, some of that trickle of warmed-up antifreeze will have the rad temp better than -5°F....less temp-shock is a good thing.
I ran the 2.2/2.5 engines for years. I used to do the turbo hop ups and had a lot of fun. What you stated is 100% the truth. I'll throw in that not just those engines, but I've seen engines overheat to no end because of trapped air. yet, I'm some high-risk roller over here by drilling a small hole and eliminating the issue entirely. Their warnings are almost 2 minutes too late... LOL
 
-
Back
Top Bottom