Is a 160 'stat available?
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
I'm fairly certain that the C7 Z will be like my old C6 Z in that it makes more power (or, at least doesn't pull power) when operated slightly cooler than stock. The reason the car runs in the 200+ f range is for 100,000 mile emissions, not optimum power. The ECM pulls timing in that range of ECT to reduce the likely hood of detonation.
Run the engine a little cooler and the timing isn't pulled and the likely hood of detonation is reduced also. This makes more power.
Maybe YOU should review some books on metallurgy, you'll find the difference in thermal expansion is minimal between 180 f, and 200 f. Running it slightly cooler will not cause excessive wear.
And no, as previously stated, it doesn't run richer at those temps, it's already in closed loop at 86 f.
If you run a 160 stat, retune the fan to come on earlier and at a higher percentage, run 20% antifreeze, 80% water, and two bottles of water wetter or the like you may not need a bigger radiator. I didn't on my C6 Z.
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
And I would suggest you review how GM has treated temps as they relate to full throttle application. When my 2015 Z06 reaches 90f oil temp and/or 180f ECT it moves the red line up to 6,500 rpm. Surely if there was a problem operating at that low of a temp then the redline wouldn't be moved.
I'm fairly certain that the C7 Z will be like my old C6 Z in that it makes more power (or, at least doesn't pull power) when operated slightly cooler than stock. The reason the car runs in the 200+ f range is for 100,000 mile emissions, not optimum power. The ECM pulls timing in that range of ECT to reduce the likely hood of detonation.
Run the engine a little cooler and the timing isn't pulled and the likely hood of detonation is reduced also. This makes more power.
Maybe YOU should review some books on metallurgy, you'll find the difference in thermal expansion is minimal between 180 f, and 200 f. Running it slightly cooler will not cause excessive wear.
And no, as previously stated, it doesn't run richer at those temps, it's already in closed loop at 86 f.
If you run a 160 stat, retune the fan to come on earlier and at a higher percentage, run 20% antifreeze, 80% water, and two bottles of water wetter or the like you may not need a bigger radiator. I didn't on my C6 Z.
I'm fairly certain that the C7 Z will be like my old C6 Z in that it makes more power (or, at least doesn't pull power) when operated slightly cooler than stock. The reason the car runs in the 200+ f range is for 100,000 mile emissions, not optimum power. The ECM pulls timing in that range of ECT to reduce the likely hood of detonation.
Run the engine a little cooler and the timing isn't pulled and the likely hood of detonation is reduced also. This makes more power.
Maybe YOU should review some books on metallurgy, you'll find the difference in thermal expansion is minimal between 180 f, and 200 f. Running it slightly cooler will not cause excessive wear.
And no, as previously stated, it doesn't run richer at those temps, it's already in closed loop at 86 f.
If you run a 160 stat, retune the fan to come on earlier and at a higher percentage, run 20% antifreeze, 80% water, and two bottles of water wetter or the like you may not need a bigger radiator. I didn't on my C6 Z.
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
Good move in the 50's, good move now. NASCAR runs higher temps not because they want to but because aerodynamics of drag for more cooling hurts speed. If they could get away with more cooling they would.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
NASCAR went to fuel injection only 25 years after the automotive industry....wait, I thought street cars improve through racing tech, not the other way around....
Do you have any actual technological documented proof that higher coolant temperatures create more horsepower? Higher oil temps can make more power up to a point by reducing viscosity but coolant temps are better off as cold as you can get them.
Do you even race a car? You don't need a thermostat to get to Starbucks, on this point you are correct.
Heck I don't even go to Starbucks anymore because I don't want to catch diabetes and I hear they serve it up hot in every cup.
Team Owner
Joined: Aug 2005
Posts: 34,988
Likes: 515
From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
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2017 C4 of Year
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Melting Slicks
Joined: Jun 2012
Posts: 2,226
Likes: 1,029
From: Thomas Texas
I don't see the point of a 160° thermostat.
Modern engines are designed around in the 200 - 220° range. I had one in my 2005 C6, but I was seeing swings from 178° to 210° I didn't think that was healthy for the motor so I changed it out to 186° From Stant. All the 160° thermostat did was reduce the floor of the coolant temperature. That resulted in these big swings when you're in traffic or on the highway. I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run.
Also you want to oil to get up to around 220° to be most effective in boiling off condensation quickly that accumulates in the oil.
The best way to increase horsepower is to reduce the air intake temperature which adds more oxygen to the combustion chamber and more fuel injected as a result. That's what makes power.
In the old days, the intake manifold were cast-iron and exposed to hot oil and coolant they ran through it. Also, fuel from the carburetor would evaporate quicker when the intake manifold was hot. However, a hot manifold increased air temperature going into the cylinders, and less dense air. Today's intake manifold hard plastic with no fuel and heat resistant. Also there's no coolant that runs through the intake manifold.
In my opinion, changing to a 160° thermostat won't make much of a difference if at all for the average guy. If you are drag racing a lot, running at a lower coolant temp really is another way of lowering the air intake temp.
Modern engines are designed around in the 200 - 220° range. I had one in my 2005 C6, but I was seeing swings from 178° to 210° I didn't think that was healthy for the motor so I changed it out to 186° From Stant. All the 160° thermostat did was reduce the floor of the coolant temperature. That resulted in these big swings when you're in traffic or on the highway. I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run.
Also you want to oil to get up to around 220° to be most effective in boiling off condensation quickly that accumulates in the oil.
The best way to increase horsepower is to reduce the air intake temperature which adds more oxygen to the combustion chamber and more fuel injected as a result. That's what makes power.
In the old days, the intake manifold were cast-iron and exposed to hot oil and coolant they ran through it. Also, fuel from the carburetor would evaporate quicker when the intake manifold was hot. However, a hot manifold increased air temperature going into the cylinders, and less dense air. Today's intake manifold hard plastic with no fuel and heat resistant. Also there's no coolant that runs through the intake manifold.
In my opinion, changing to a 160° thermostat won't make much of a difference if at all for the average guy. If you are drag racing a lot, running at a lower coolant temp really is another way of lowering the air intake temp.
Last edited by RussM05; Feb 3, 2015 at 10:10 PM.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
I don't see the point of a 160° thermostat.
Modern engines are designed around in the 200 - 220° range. I had one in my 2005 C6, but I was seeing swings from 178° to 210° I didn't think that was healthy for the motor so I changed it out to 186° From Stant. All the 160° thermostat did was reduce the floor of the coolant temperature. That resulted in these big swings when you're in traffic or on the highway. I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run.
Also you want to oil to get up to around 220° to be most effective in boiling off condensation quickly that accumulates in the oil.
The best way to increase horsepower is to reduce the air intake temperature which adds more oxygen to the combustion chamber and more fuel injected as a result. That's what makes power.
In the old days, the intake manifold were cast-iron and exposed to hot oil and coolant they ran through it. Also, fuel from the carburetor would evaporate quicker when the intake manifold was hot. However, a hot manifold increased air temperature going into the cylinders, and less dense air. Today's intake manifold hard plastic with no fuel and heat resistant. Also there's no coolant that runs through the intake manifold.
In my opinion, changing to a 160° thermostat won't make much of a difference if at all for the average guy. If you are drag racing a lot, running at a lower coolant temp really is another way of lowering the air intake temp.
Modern engines are designed around in the 200 - 220° range. I had one in my 2005 C6, but I was seeing swings from 178° to 210° I didn't think that was healthy for the motor so I changed it out to 186° From Stant. All the 160° thermostat did was reduce the floor of the coolant temperature. That resulted in these big swings when you're in traffic or on the highway. I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run.
Also you want to oil to get up to around 220° to be most effective in boiling off condensation quickly that accumulates in the oil.
The best way to increase horsepower is to reduce the air intake temperature which adds more oxygen to the combustion chamber and more fuel injected as a result. That's what makes power.
In the old days, the intake manifold were cast-iron and exposed to hot oil and coolant they ran through it. Also, fuel from the carburetor would evaporate quicker when the intake manifold was hot. However, a hot manifold increased air temperature going into the cylinders, and less dense air. Today's intake manifold hard plastic with no fuel and heat resistant. Also there's no coolant that runs through the intake manifold.
In my opinion, changing to a 160° thermostat won't make much of a difference if at all for the average guy. If you are drag racing a lot, running at a lower coolant temp really is another way of lowering the air intake temp.
You say cooler coolant temps don't do anything for today's engines. You say it is better to reduce intake temps. Then you say reducing coolant temps is another way to reduce intake temps.
We need oil to be at 212 to boil off condensation? First of all, 212 is the boiling point of water under 1 atmosphere. If you pressurize it, the boiling point is higher. If you put it under a vacuum, it is lower. A crankcase is under vacuum....you know like pcv system.....
Not to mention if evaporation required boiling temperatures, we would all be long since dead.....you don't need anything even close to 212 to "burn off moisture."
Coolant/water and oil heat up at different rates and retain heat for different periods. Hot oil is good (up to a point), hot coolant is NEVER good. If I could have 220 degree oil and 40 degree coolant I would. The oil is still going to heat up even if the coolant stays cool.....the thermostat doesn't regulate oil temps and coolant temp has little impact on your oil temps.
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
"Also you want to oil to get up to around 220° to be most effective in boiling off condensation quickly that accumulates in the oil."
That's another fallacy that keeps getting repeated on here. So sad, and WRONG. Take the cover off your hot tub and watch the water vapor flying off. And that is at 100 to 120 f. Read up on partial pressure, you'll see what I'm saying. And that's without the partial vacuum of the PCV system.
"I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run."
Yet again, oft repeated, rarely seen. It usually happens when you have a bad tuner, setting the fan percentage above 90%. Didn't happen in 7 years with my C5, with fans reset, and didn't happen in 8 years with my C6Z, setting the fan at 90% max, in New Mexico heat.
BTW: I did give you wrong numbers earlier. Sorry about that. I went for a drive from cold watching exactly when the suggested redline moves with temps. My C7Z resets the redline when warming up to 6,500 rpm when the coolant temp reaches 165f and 75f for the oil. That would be fully warmed up for GM. And that says volumes for what temps are normal and OK for full throttle, high rpm use of these motors.
Again, these motors are set to operate at above 200f purely for emissions. They will operate safely and make more power at around 180f for many tens of thousands of miles.
This is the tech/performance section, where you are most likely to see mods to improve performance. But this one particular mod seems to garner so many haters with a different opinion on whether it works. Opinions are cool, but facts with substantiation are better. Running the engine a little cooler makes more horsepower. That's a fact, and it's especially true with our modern (not 1950's engines, lol) computer controlled engines. They are tuned to run right on the edge of detonation for maximum efficiency. Run them a little cooler and the computer will allow them to make a little more horsepower. Run the quarter mile after cooling down your engine. Run again keeping it hot, you'll see a drop in MPH. That's a loss of horsepower. Running your engine cooler also does no harm to your engine, all these terrible things people keep bringing up (with no substantiation) are old wife's tales, they all can be refuted easily, with facts.
That's another fallacy that keeps getting repeated on here. So sad, and WRONG. Take the cover off your hot tub and watch the water vapor flying off. And that is at 100 to 120 f. Read up on partial pressure, you'll see what I'm saying. And that's without the partial vacuum of the PCV system.
"I did change my fans in the tune it helped a little but they can also result in problems with the overheating the connector in reducing the fans life in the long run."
Yet again, oft repeated, rarely seen. It usually happens when you have a bad tuner, setting the fan percentage above 90%. Didn't happen in 7 years with my C5, with fans reset, and didn't happen in 8 years with my C6Z, setting the fan at 90% max, in New Mexico heat.
BTW: I did give you wrong numbers earlier. Sorry about that. I went for a drive from cold watching exactly when the suggested redline moves with temps. My C7Z resets the redline when warming up to 6,500 rpm when the coolant temp reaches 165f and 75f for the oil. That would be fully warmed up for GM. And that says volumes for what temps are normal and OK for full throttle, high rpm use of these motors.
Again, these motors are set to operate at above 200f purely for emissions. They will operate safely and make more power at around 180f for many tens of thousands of miles.
This is the tech/performance section, where you are most likely to see mods to improve performance. But this one particular mod seems to garner so many haters with a different opinion on whether it works. Opinions are cool, but facts with substantiation are better. Running the engine a little cooler makes more horsepower. That's a fact, and it's especially true with our modern (not 1950's engines, lol) computer controlled engines. They are tuned to run right on the edge of detonation for maximum efficiency. Run them a little cooler and the computer will allow them to make a little more horsepower. Run the quarter mile after cooling down your engine. Run again keeping it hot, you'll see a drop in MPH. That's a loss of horsepower. Running your engine cooler also does no harm to your engine, all these terrible things people keep bringing up (with no substantiation) are old wife's tales, they all can be refuted easily, with facts.
Last edited by 6Speeder; Feb 4, 2015 at 09:49 AM.
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Melting Slicks
Joined: Jun 2012
Posts: 2,226
Likes: 1,029
From: Thomas Texas
Good debate here. This subject has been hotly debated and perhaps there is no right or wrong. Depends on what the engine is designed to do. For racing, if running a low temp 'stat has proven to improve times, then OK. For the street, I see more data that says stick with the stock 'stat.
Here is an article that supports my view:
Link:
http://www.tuneruniversity.com/blog/...the-advantage/
Low Temp Thermostats: What’s the Advantage?
This week we’re talking about low temperature thermostats, another item that nearly every tuning house sells and yet fail to really explain what they’re for. A few months back, we talked about high pressure radiator caps and what advantage they offered, this time though we’re looking at a part that is far more perplexing.
Here are a few descriptions from websites/manufacturers selling these, notice the trend of extremely vague language:
The SPOON Low Temp Thermostat S2000 Integra Civic will increase the vehicles cooling ability (false) by changing the operation temperature from 90C (stock)[194] to as low as 80C [176F]. This in turn will give your Honda a chance to be free of overheating (false). For best results, it is recommended that the Thermostat be used in conjunction with a low temperature Thermo Switch.
The SARD Low Temperature Thermostat – SST12 Mazda is a drop-in direct replacement for your OEM unit. The Sard unit will lower the temperature at which the cool water can mix with the warmer temperatures inside the engine (true). This will lead to a motor than can now run much more efficiently (false).
The FEEL’S Low Temperature Thermostat Civic FD2 will provide better, more reliable and faster cooling for your FD2 (false). By lowering the opening temperature to 68 degrees, and full open at 82 degrees there is a smooth transition in cooling (???), and you engine will be cooled optimally faster (?).
The MUGEN Low Temp Thermostat NSX S2000 will increase the vehicle cooling ability (still false) by allowing the circulation of the chilled water earlier than the OEM unit would allow it to (that part, true). Stock thermostats are intended for normal driving conditions and aren’t made for those intending to give their car a work-out (false).
Reading these make you believe that a low temp thermostat are a good idea for those “pushing their car harder” and that they somehow improve cooling performance. There are other descriptions that also seem to indicate that they lower engine/intake temps to make more power. All rubbish.
The Function of the Thermostat & Cooling System Basics
The biggest misunderstanding about thermostats is that people believe they make the engine run cooler. They don’t necessarily do that. The cooling system and load on the engine determines how hot the engine gets, the thermostat fully open will still be the mercy of the coolant system’s ability to remove heat.
Most engines run slightly above the thermostat’s minimum opening temperature under normal loads. Under high loads, they will run at or above the thermostat’s fully open temperature – in other words, under hard driving, the thermostat’s opening temperature is completely irrelevant.
The thermostat can only determine when the cooling system is allowed to start cooling the engine. It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the water is to cold, it turns up the hot water.By regulating the flow through the cooling system it speeds up and slows down the flow of coolant into and out of the engine block.
In liquid cooling systems, the ability to cool is determined by a number of factors, but the basic keys are the surface area of the radiator (how big/how many small fins), the air flow through the radiator (fans on/off, speed of car), and how quickly or slowly the cooling fluid goes through the radiator. If the coolant spends a small amount of time in the radiator, it loses less heat. If it spends a lot of time there, it loses far more heat. Therefore you don’t want the flow to be too high as the cooling system’s ability to cool the engine will be reduced, not increased.
The thermostat is there primarily to help the engine warm up in the morning. As we discussed in a previous article, the engine is designed to operate at it’s operating temperature. Most engine wear occurs when the engine is cold, once it’s warmed up there is very little wear in a healthy engine. Thus, we definitely want to run a thermostat to allow the engine to warm up as quickly as possible until it reaches our desired and designed operating temperature.
If the engine is below operating temperature, the bearings, rings, and other components are not yet expanded in size and therefore they “bang” against the other metals in the engine more than they would at operating temperature. No good.
So if we don’t run a thermostat at all, it takes a lot of constant load to get the engine properly warmed up and to keep it up to temperature on cold days. We also in some circumstances may experience overheating if flow through the system is too high as the coolant has to spend a certain amount of time in the radiator to actually cool down.
Some race teams do choose not to run a thermostat, but they are the minority. They usually run at least a restriction plate in place of the thermostat to slow down flow and allow some warm up to occur. The reason that they may not run one at all is usually to remove a point of failure in endurance type races. In other words, if the thermostat fails and sticks closed, it could cause a pit stop or end the race. By removing it, they tolerate possible engine wear since they know they’ll be at high loads throughout the race. Their cooling system is usually tuned to compensate for the lack of a thermostat as well.
Running the factory thermostat will on the other hand ensure that the engine comes up to the designed minimum temperature very quickly. Until the engine is up to temperature, there is no cooling occurring. The factory thermostat will not however change how the engine runs under load because the thermostat will be fully open when under load. It effectively isn’t there under load.
What they’re used for
So what then would a low temperature thermostat accomplish? Not much.
Around town and in the pits, you warm up faster than no thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get there however, especially on warm days, the only difference is you’re trying to cool the car off as it’s trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator fans kick on since radiators are poor cooling devices without air flow. In other words, sitting still, the thermostat opening temperature doesn’t matter much at all.
Once you’re moving, on the highway, with a 160 degree thermostat on a cooler day you could be cruising at 160-180 degrees (opening temp->designed operating temp). This is possible because the load on the engine is low and the outside temps are low. Therefore, the thermostat opening temp maters somewhat here. If you’re coasting down a mountain, it will be a certainty that your coolant will reach the thermostat minimum if you coast long enough.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be running at a temperature lower than it’s design intended. The result is increased wear on the engine’s internals. It’s essentially the same as if you assembled the engine with clearances tighter than designed for because you didn’t follow the directions or your tools were not calibrated properly.
As for the intake temperature argument, while cooling the intake manifold down could be useful, there are a few problems with the argument. The first is that very little heat is transferred from the intake manifold to the intake charge, period. The intake charge is moving very fast and there is a LOT of air flowing through. The surface area of the intake system is very small and the temperature differential in real terms is not that high. There is already very little heat being added to the intake charge by the intake system regardless of what some ads claim. If the new thermostat DID bring the temps of the intake manifold down 20 degrees, the actual change in intake temps would be negligible to 0 on the road.
Regardless, it would take literally a second or two before temps would be regulated by the cooling system, not the thermostat anyway since under load the engine is going to run well above the thermostat fully open mark anyway.
Remember that the thermostat is fully open pretty much any time the engine is under full load because the coolant temperatures spike pretty quickly.
In a race car, the floor (opening temp) of the thermostat is completely irrelevant unless you are running a very efficient and large radiator. Once you’re out on the track for half a lap or so, your coolant temps are going to be in the 200 range anyway so the thermostat is fully open regardless.
You can use a low temp as a “band-aid” at the track sometimes. For example, if you know that your coolant temps are hitting the opening temp of your current thermostat at points the track and you’re experiencing mild overheating, you might be able to patch this up by using a lower temp thermostat, especially if you’re willing to run your radiator fans manually to help.
Why? Because during low load parts of the track you allow the coolant system to cool off more which means it will cope with higher load sections a bit better and may chase of mild overheating problems. This is acceptable on a race track as a temporary solution as wear is usually an acceptable compromise to get through the race. However, the right solution is to upgrade the radiator or check for possible malfunctioning sections of the cooling system. It is also more acceptable here because load is high during a race. On the street, even on hard drives, it’s usually reasonably low.
Conclusion
So if you want to test this, the best thing to do is get an OBDII scanner and go out in an OBDII car and monitor the ECT sensor and watch how coolant temps regulate and spike as load changes.
The bottom line however is that in a street car, you’re increasing wear and getting no benefit. In a race car, it’s a band-aid but not one that you should plan to rely on.
If you’re having overheating problems, check the cooling system thoroughly and if all is well, upgrade the radiator, fans or even the water pump — not the thermostat. If your coolant gauge never goes above normal then your cooling system is adequate for your use of the car.
If you’re chasing more power, this isn’t a place to look. Any power gain would be circumstantial (ie, only under certain conditions), incredibly negligible, and at the risk of accelerated wear on your expensive engine internals (especially in street cars).
Here is an article that supports my view:
Link:
http://www.tuneruniversity.com/blog/...the-advantage/
Low Temp Thermostats: What’s the Advantage?
This week we’re talking about low temperature thermostats, another item that nearly every tuning house sells and yet fail to really explain what they’re for. A few months back, we talked about high pressure radiator caps and what advantage they offered, this time though we’re looking at a part that is far more perplexing.
Here are a few descriptions from websites/manufacturers selling these, notice the trend of extremely vague language:
The SPOON Low Temp Thermostat S2000 Integra Civic will increase the vehicles cooling ability (false) by changing the operation temperature from 90C (stock)[194] to as low as 80C [176F]. This in turn will give your Honda a chance to be free of overheating (false). For best results, it is recommended that the Thermostat be used in conjunction with a low temperature Thermo Switch.
The SARD Low Temperature Thermostat – SST12 Mazda is a drop-in direct replacement for your OEM unit. The Sard unit will lower the temperature at which the cool water can mix with the warmer temperatures inside the engine (true). This will lead to a motor than can now run much more efficiently (false).
The FEEL’S Low Temperature Thermostat Civic FD2 will provide better, more reliable and faster cooling for your FD2 (false). By lowering the opening temperature to 68 degrees, and full open at 82 degrees there is a smooth transition in cooling (???), and you engine will be cooled optimally faster (?).
The MUGEN Low Temp Thermostat NSX S2000 will increase the vehicle cooling ability (still false) by allowing the circulation of the chilled water earlier than the OEM unit would allow it to (that part, true). Stock thermostats are intended for normal driving conditions and aren’t made for those intending to give their car a work-out (false).
Reading these make you believe that a low temp thermostat are a good idea for those “pushing their car harder” and that they somehow improve cooling performance. There are other descriptions that also seem to indicate that they lower engine/intake temps to make more power. All rubbish.
The Function of the Thermostat & Cooling System Basics
The biggest misunderstanding about thermostats is that people believe they make the engine run cooler. They don’t necessarily do that. The cooling system and load on the engine determines how hot the engine gets, the thermostat fully open will still be the mercy of the coolant system’s ability to remove heat.
Most engines run slightly above the thermostat’s minimum opening temperature under normal loads. Under high loads, they will run at or above the thermostat’s fully open temperature – in other words, under hard driving, the thermostat’s opening temperature is completely irrelevant.
The thermostat can only determine when the cooling system is allowed to start cooling the engine. It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the water is to cold, it turns up the hot water.By regulating the flow through the cooling system it speeds up and slows down the flow of coolant into and out of the engine block.
In liquid cooling systems, the ability to cool is determined by a number of factors, but the basic keys are the surface area of the radiator (how big/how many small fins), the air flow through the radiator (fans on/off, speed of car), and how quickly or slowly the cooling fluid goes through the radiator. If the coolant spends a small amount of time in the radiator, it loses less heat. If it spends a lot of time there, it loses far more heat. Therefore you don’t want the flow to be too high as the cooling system’s ability to cool the engine will be reduced, not increased.
The thermostat is there primarily to help the engine warm up in the morning. As we discussed in a previous article, the engine is designed to operate at it’s operating temperature. Most engine wear occurs when the engine is cold, once it’s warmed up there is very little wear in a healthy engine. Thus, we definitely want to run a thermostat to allow the engine to warm up as quickly as possible until it reaches our desired and designed operating temperature.
If the engine is below operating temperature, the bearings, rings, and other components are not yet expanded in size and therefore they “bang” against the other metals in the engine more than they would at operating temperature. No good.
So if we don’t run a thermostat at all, it takes a lot of constant load to get the engine properly warmed up and to keep it up to temperature on cold days. We also in some circumstances may experience overheating if flow through the system is too high as the coolant has to spend a certain amount of time in the radiator to actually cool down.
Some race teams do choose not to run a thermostat, but they are the minority. They usually run at least a restriction plate in place of the thermostat to slow down flow and allow some warm up to occur. The reason that they may not run one at all is usually to remove a point of failure in endurance type races. In other words, if the thermostat fails and sticks closed, it could cause a pit stop or end the race. By removing it, they tolerate possible engine wear since they know they’ll be at high loads throughout the race. Their cooling system is usually tuned to compensate for the lack of a thermostat as well.
Running the factory thermostat will on the other hand ensure that the engine comes up to the designed minimum temperature very quickly. Until the engine is up to temperature, there is no cooling occurring. The factory thermostat will not however change how the engine runs under load because the thermostat will be fully open when under load. It effectively isn’t there under load.
What they’re used for
So what then would a low temperature thermostat accomplish? Not much.
Around town and in the pits, you warm up faster than no thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get there however, especially on warm days, the only difference is you’re trying to cool the car off as it’s trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator fans kick on since radiators are poor cooling devices without air flow. In other words, sitting still, the thermostat opening temperature doesn’t matter much at all.
Once you’re moving, on the highway, with a 160 degree thermostat on a cooler day you could be cruising at 160-180 degrees (opening temp->designed operating temp). This is possible because the load on the engine is low and the outside temps are low. Therefore, the thermostat opening temp maters somewhat here. If you’re coasting down a mountain, it will be a certainty that your coolant will reach the thermostat minimum if you coast long enough.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be running at a temperature lower than it’s design intended. The result is increased wear on the engine’s internals. It’s essentially the same as if you assembled the engine with clearances tighter than designed for because you didn’t follow the directions or your tools were not calibrated properly.
As for the intake temperature argument, while cooling the intake manifold down could be useful, there are a few problems with the argument. The first is that very little heat is transferred from the intake manifold to the intake charge, period. The intake charge is moving very fast and there is a LOT of air flowing through. The surface area of the intake system is very small and the temperature differential in real terms is not that high. There is already very little heat being added to the intake charge by the intake system regardless of what some ads claim. If the new thermostat DID bring the temps of the intake manifold down 20 degrees, the actual change in intake temps would be negligible to 0 on the road.
Regardless, it would take literally a second or two before temps would be regulated by the cooling system, not the thermostat anyway since under load the engine is going to run well above the thermostat fully open mark anyway.
Remember that the thermostat is fully open pretty much any time the engine is under full load because the coolant temperatures spike pretty quickly.
In a race car, the floor (opening temp) of the thermostat is completely irrelevant unless you are running a very efficient and large radiator. Once you’re out on the track for half a lap or so, your coolant temps are going to be in the 200 range anyway so the thermostat is fully open regardless.
You can use a low temp as a “band-aid” at the track sometimes. For example, if you know that your coolant temps are hitting the opening temp of your current thermostat at points the track and you’re experiencing mild overheating, you might be able to patch this up by using a lower temp thermostat, especially if you’re willing to run your radiator fans manually to help.
Why? Because during low load parts of the track you allow the coolant system to cool off more which means it will cope with higher load sections a bit better and may chase of mild overheating problems. This is acceptable on a race track as a temporary solution as wear is usually an acceptable compromise to get through the race. However, the right solution is to upgrade the radiator or check for possible malfunctioning sections of the cooling system. It is also more acceptable here because load is high during a race. On the street, even on hard drives, it’s usually reasonably low.
Conclusion
So if you want to test this, the best thing to do is get an OBDII scanner and go out in an OBDII car and monitor the ECT sensor and watch how coolant temps regulate and spike as load changes.
The bottom line however is that in a street car, you’re increasing wear and getting no benefit. In a race car, it’s a band-aid but not one that you should plan to rely on.
If you’re having overheating problems, check the cooling system thoroughly and if all is well, upgrade the radiator, fans or even the water pump — not the thermostat. If your coolant gauge never goes above normal then your cooling system is adequate for your use of the car.
If you’re chasing more power, this isn’t a place to look. Any power gain would be circumstantial (ie, only under certain conditions), incredibly negligible, and at the risk of accelerated wear on your expensive engine internals (especially in street cars).
Melting Slicks
Joined: Dec 2011
Posts: 2,690
Likes: 116
From: Richmond area Va
Pro
Joined: Oct 2008
Posts: 606
Likes: 7
From: Nashville, TN
Good debate here. This subject has been hotly debated and perhaps there is no right or wrong. Depends on what the engine is designed to do. For racing, if running a low temp 'stat has proven to improve times, then OK. For the street, I see more data that says stick with the stock 'stat.
Here is an article that supports my view:
Link:
http://www.tuneruniversity.com/blog/...the-advantage/
Low Temp Thermostats: What’s the Advantage?
This week we’re talking about low temperature thermostats, another item that nearly every tuning house sells and yet fail to really explain what they’re for. A few months back, we talked about high pressure radiator caps and what advantage they offered, this time though we’re looking at a part that is far more perplexing.
Here are a few descriptions from websites/manufacturers selling these, notice the trend of extremely vague language:
The SPOON Low Temp Thermostat S2000 Integra Civic will increase the vehicles cooling ability (false) by changing the operation temperature from 90C (stock)[194] to as low as 80C [176F]. This in turn will give your Honda a chance to be free of overheating (false). For best results, it is recommended that the Thermostat be used in conjunction with a low temperature Thermo Switch.
The SARD Low Temperature Thermostat – SST12 Mazda is a drop-in direct replacement for your OEM unit. The Sard unit will lower the temperature at which the cool water can mix with the warmer temperatures inside the engine (true). This will lead to a motor than can now run much more efficiently (false).
The FEEL’S Low Temperature Thermostat Civic FD2 will provide better, more reliable and faster cooling for your FD2 (false). By lowering the opening temperature to 68 degrees, and full open at 82 degrees there is a smooth transition in cooling (???), and you engine will be cooled optimally faster (?).
The MUGEN Low Temp Thermostat NSX S2000 will increase the vehicle cooling ability (still false) by allowing the circulation of the chilled water earlier than the OEM unit would allow it to (that part, true). Stock thermostats are intended for normal driving conditions and aren’t made for those intending to give their car a work-out (false).
Reading these make you believe that a low temp thermostat are a good idea for those “pushing their car harder” and that they somehow improve cooling performance. There are other descriptions that also seem to indicate that they lower engine/intake temps to make more power. All rubbish.
The Function of the Thermostat & Cooling System Basics
The biggest misunderstanding about thermostats is that people believe they make the engine run cooler. They don’t necessarily do that. The cooling system and load on the engine determines how hot the engine gets, the thermostat fully open will still be the mercy of the coolant system’s ability to remove heat.
Most engines run slightly above the thermostat’s minimum opening temperature under normal loads. Under high loads, they will run at or above the thermostat’s fully open temperature – in other words, under hard driving, the thermostat’s opening temperature is completely irrelevant.
The thermostat can only determine when the cooling system is allowed to start cooling the engine. It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the water is to cold, it turns up the hot water.By regulating the flow through the cooling system it speeds up and slows down the flow of coolant into and out of the engine block.
In liquid cooling systems, the ability to cool is determined by a number of factors, but the basic keys are the surface area of the radiator (how big/how many small fins), the air flow through the radiator (fans on/off, speed of car), and how quickly or slowly the cooling fluid goes through the radiator. If the coolant spends a small amount of time in the radiator, it loses less heat. If it spends a lot of time there, it loses far more heat. Therefore you don’t want the flow to be too high as the cooling system’s ability to cool the engine will be reduced, not increased.
The thermostat is there primarily to help the engine warm up in the morning. As we discussed in a previous article, the engine is designed to operate at it’s operating temperature. Most engine wear occurs when the engine is cold, once it’s warmed up there is very little wear in a healthy engine. Thus, we definitely want to run a thermostat to allow the engine to warm up as quickly as possible until it reaches our desired and designed operating temperature.
If the engine is below operating temperature, the bearings, rings, and other components are not yet expanded in size and therefore they “bang” against the other metals in the engine more than they would at operating temperature. No good.
So if we don’t run a thermostat at all, it takes a lot of constant load to get the engine properly warmed up and to keep it up to temperature on cold days. We also in some circumstances may experience overheating if flow through the system is too high as the coolant has to spend a certain amount of time in the radiator to actually cool down.
Some race teams do choose not to run a thermostat, but they are the minority. They usually run at least a restriction plate in place of the thermostat to slow down flow and allow some warm up to occur. The reason that they may not run one at all is usually to remove a point of failure in endurance type races. In other words, if the thermostat fails and sticks closed, it could cause a pit stop or end the race. By removing it, they tolerate possible engine wear since they know they’ll be at high loads throughout the race. Their cooling system is usually tuned to compensate for the lack of a thermostat as well.
Running the factory thermostat will on the other hand ensure that the engine comes up to the designed minimum temperature very quickly. Until the engine is up to temperature, there is no cooling occurring. The factory thermostat will not however change how the engine runs under load because the thermostat will be fully open when under load. It effectively isn’t there under load.
What they’re used for
So what then would a low temperature thermostat accomplish? Not much.
Around town and in the pits, you warm up faster than no thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get there however, especially on warm days, the only difference is you’re trying to cool the car off as it’s trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator fans kick on since radiators are poor cooling devices without air flow. In other words, sitting still, the thermostat opening temperature doesn’t matter much at all.
Once you’re moving, on the highway, with a 160 degree thermostat on a cooler day you could be cruising at 160-180 degrees (opening temp->designed operating temp). This is possible because the load on the engine is low and the outside temps are low. Therefore, the thermostat opening temp maters somewhat here. If you’re coasting down a mountain, it will be a certainty that your coolant will reach the thermostat minimum if you coast long enough.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be running at a temperature lower than it’s design intended. The result is increased wear on the engine’s internals. It’s essentially the same as if you assembled the engine with clearances tighter than designed for because you didn’t follow the directions or your tools were not calibrated properly.
As for the intake temperature argument, while cooling the intake manifold down could be useful, there are a few problems with the argument. The first is that very little heat is transferred from the intake manifold to the intake charge, period. The intake charge is moving very fast and there is a LOT of air flowing through. The surface area of the intake system is very small and the temperature differential in real terms is not that high. There is already very little heat being added to the intake charge by the intake system regardless of what some ads claim. If the new thermostat DID bring the temps of the intake manifold down 20 degrees, the actual change in intake temps would be negligible to 0 on the road.
Regardless, it would take literally a second or two before temps would be regulated by the cooling system, not the thermostat anyway since under load the engine is going to run well above the thermostat fully open mark anyway.
Remember that the thermostat is fully open pretty much any time the engine is under full load because the coolant temperatures spike pretty quickly.
In a race car, the floor (opening temp) of the thermostat is completely irrelevant unless you are running a very efficient and large radiator. Once you’re out on the track for half a lap or so, your coolant temps are going to be in the 200 range anyway so the thermostat is fully open regardless.
You can use a low temp as a “band-aid” at the track sometimes. For example, if you know that your coolant temps are hitting the opening temp of your current thermostat at points the track and you’re experiencing mild overheating, you might be able to patch this up by using a lower temp thermostat, especially if you’re willing to run your radiator fans manually to help.
Why? Because during low load parts of the track you allow the coolant system to cool off more which means it will cope with higher load sections a bit better and may chase of mild overheating problems. This is acceptable on a race track as a temporary solution as wear is usually an acceptable compromise to get through the race. However, the right solution is to upgrade the radiator or check for possible malfunctioning sections of the cooling system. It is also more acceptable here because load is high during a race. On the street, even on hard drives, it’s usually reasonably low.
Conclusion
So if you want to test this, the best thing to do is get an OBDII scanner and go out in an OBDII car and monitor the ECT sensor and watch how coolant temps regulate and spike as load changes.
The bottom line however is that in a street car, you’re increasing wear and getting no benefit. In a race car, it’s a band-aid but not one that you should plan to rely on.
If you’re having overheating problems, check the cooling system thoroughly and if all is well, upgrade the radiator, fans or even the water pump — not the thermostat. If your coolant gauge never goes above normal then your cooling system is adequate for your use of the car.
If you’re chasing more power, this isn’t a place to look. Any power gain would be circumstantial (ie, only under certain conditions), incredibly negligible, and at the risk of accelerated wear on your expensive engine internals (especially in street cars).
Here is an article that supports my view:
Link:
http://www.tuneruniversity.com/blog/...the-advantage/
Low Temp Thermostats: What’s the Advantage?
This week we’re talking about low temperature thermostats, another item that nearly every tuning house sells and yet fail to really explain what they’re for. A few months back, we talked about high pressure radiator caps and what advantage they offered, this time though we’re looking at a part that is far more perplexing.
Here are a few descriptions from websites/manufacturers selling these, notice the trend of extremely vague language:
The SPOON Low Temp Thermostat S2000 Integra Civic will increase the vehicles cooling ability (false) by changing the operation temperature from 90C (stock)[194] to as low as 80C [176F]. This in turn will give your Honda a chance to be free of overheating (false). For best results, it is recommended that the Thermostat be used in conjunction with a low temperature Thermo Switch.
The SARD Low Temperature Thermostat – SST12 Mazda is a drop-in direct replacement for your OEM unit. The Sard unit will lower the temperature at which the cool water can mix with the warmer temperatures inside the engine (true). This will lead to a motor than can now run much more efficiently (false).
The FEEL’S Low Temperature Thermostat Civic FD2 will provide better, more reliable and faster cooling for your FD2 (false). By lowering the opening temperature to 68 degrees, and full open at 82 degrees there is a smooth transition in cooling (???), and you engine will be cooled optimally faster (?).
The MUGEN Low Temp Thermostat NSX S2000 will increase the vehicle cooling ability (still false) by allowing the circulation of the chilled water earlier than the OEM unit would allow it to (that part, true). Stock thermostats are intended for normal driving conditions and aren’t made for those intending to give their car a work-out (false).
Reading these make you believe that a low temp thermostat are a good idea for those “pushing their car harder” and that they somehow improve cooling performance. There are other descriptions that also seem to indicate that they lower engine/intake temps to make more power. All rubbish.
The Function of the Thermostat & Cooling System Basics
The biggest misunderstanding about thermostats is that people believe they make the engine run cooler. They don’t necessarily do that. The cooling system and load on the engine determines how hot the engine gets, the thermostat fully open will still be the mercy of the coolant system’s ability to remove heat.
Most engines run slightly above the thermostat’s minimum opening temperature under normal loads. Under high loads, they will run at or above the thermostat’s fully open temperature – in other words, under hard driving, the thermostat’s opening temperature is completely irrelevant.
The thermostat can only determine when the cooling system is allowed to start cooling the engine. It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the water is to cold, it turns up the hot water.By regulating the flow through the cooling system it speeds up and slows down the flow of coolant into and out of the engine block.
In liquid cooling systems, the ability to cool is determined by a number of factors, but the basic keys are the surface area of the radiator (how big/how many small fins), the air flow through the radiator (fans on/off, speed of car), and how quickly or slowly the cooling fluid goes through the radiator. If the coolant spends a small amount of time in the radiator, it loses less heat. If it spends a lot of time there, it loses far more heat. Therefore you don’t want the flow to be too high as the cooling system’s ability to cool the engine will be reduced, not increased.
The thermostat is there primarily to help the engine warm up in the morning. As we discussed in a previous article, the engine is designed to operate at it’s operating temperature. Most engine wear occurs when the engine is cold, once it’s warmed up there is very little wear in a healthy engine. Thus, we definitely want to run a thermostat to allow the engine to warm up as quickly as possible until it reaches our desired and designed operating temperature.
If the engine is below operating temperature, the bearings, rings, and other components are not yet expanded in size and therefore they “bang” against the other metals in the engine more than they would at operating temperature. No good.
So if we don’t run a thermostat at all, it takes a lot of constant load to get the engine properly warmed up and to keep it up to temperature on cold days. We also in some circumstances may experience overheating if flow through the system is too high as the coolant has to spend a certain amount of time in the radiator to actually cool down.
Some race teams do choose not to run a thermostat, but they are the minority. They usually run at least a restriction plate in place of the thermostat to slow down flow and allow some warm up to occur. The reason that they may not run one at all is usually to remove a point of failure in endurance type races. In other words, if the thermostat fails and sticks closed, it could cause a pit stop or end the race. By removing it, they tolerate possible engine wear since they know they’ll be at high loads throughout the race. Their cooling system is usually tuned to compensate for the lack of a thermostat as well.
Running the factory thermostat will on the other hand ensure that the engine comes up to the designed minimum temperature very quickly. Until the engine is up to temperature, there is no cooling occurring. The factory thermostat will not however change how the engine runs under load because the thermostat will be fully open when under load. It effectively isn’t there under load.
What they’re used for
So what then would a low temperature thermostat accomplish? Not much.
Around town and in the pits, you warm up faster than no thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get there however, especially on warm days, the only difference is you’re trying to cool the car off as it’s trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator fans kick on since radiators are poor cooling devices without air flow. In other words, sitting still, the thermostat opening temperature doesn’t matter much at all.
Once you’re moving, on the highway, with a 160 degree thermostat on a cooler day you could be cruising at 160-180 degrees (opening temp->designed operating temp). This is possible because the load on the engine is low and the outside temps are low. Therefore, the thermostat opening temp maters somewhat here. If you’re coasting down a mountain, it will be a certainty that your coolant will reach the thermostat minimum if you coast long enough.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be running at a temperature lower than it’s design intended. The result is increased wear on the engine’s internals. It’s essentially the same as if you assembled the engine with clearances tighter than designed for because you didn’t follow the directions or your tools were not calibrated properly.
As for the intake temperature argument, while cooling the intake manifold down could be useful, there are a few problems with the argument. The first is that very little heat is transferred from the intake manifold to the intake charge, period. The intake charge is moving very fast and there is a LOT of air flowing through. The surface area of the intake system is very small and the temperature differential in real terms is not that high. There is already very little heat being added to the intake charge by the intake system regardless of what some ads claim. If the new thermostat DID bring the temps of the intake manifold down 20 degrees, the actual change in intake temps would be negligible to 0 on the road.
Regardless, it would take literally a second or two before temps would be regulated by the cooling system, not the thermostat anyway since under load the engine is going to run well above the thermostat fully open mark anyway.
Remember that the thermostat is fully open pretty much any time the engine is under full load because the coolant temperatures spike pretty quickly.
In a race car, the floor (opening temp) of the thermostat is completely irrelevant unless you are running a very efficient and large radiator. Once you’re out on the track for half a lap or so, your coolant temps are going to be in the 200 range anyway so the thermostat is fully open regardless.
You can use a low temp as a “band-aid” at the track sometimes. For example, if you know that your coolant temps are hitting the opening temp of your current thermostat at points the track and you’re experiencing mild overheating, you might be able to patch this up by using a lower temp thermostat, especially if you’re willing to run your radiator fans manually to help.
Why? Because during low load parts of the track you allow the coolant system to cool off more which means it will cope with higher load sections a bit better and may chase of mild overheating problems. This is acceptable on a race track as a temporary solution as wear is usually an acceptable compromise to get through the race. However, the right solution is to upgrade the radiator or check for possible malfunctioning sections of the cooling system. It is also more acceptable here because load is high during a race. On the street, even on hard drives, it’s usually reasonably low.
Conclusion
So if you want to test this, the best thing to do is get an OBDII scanner and go out in an OBDII car and monitor the ECT sensor and watch how coolant temps regulate and spike as load changes.
The bottom line however is that in a street car, you’re increasing wear and getting no benefit. In a race car, it’s a band-aid but not one that you should plan to rely on.
If you’re having overheating problems, check the cooling system thoroughly and if all is well, upgrade the radiator, fans or even the water pump — not the thermostat. If your coolant gauge never goes above normal then your cooling system is adequate for your use of the car.
If you’re chasing more power, this isn’t a place to look. Any power gain would be circumstantial (ie, only under certain conditions), incredibly negligible, and at the risk of accelerated wear on your expensive engine internals (especially in street cars).
Sorry but this guy does not know what he is talking about and doesn't have the education, experience, or data to back up his opinion.
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
RUSS: nice link, however no facts presented, only opinions.
More wear at lower temps? Where's the data? Remember, we're talking about running at 180 Vs. 200. That's only a 3% shift in temps (remember start at zero kelvin). If this was a problem then the poor engines would wear out or break after a few thousand cold starts, no matter what thermostat you are running. Again, it states wear from being below operating temp. Check it yourself, the C7Z sets the redline based on temps, oil and water. Mine goes to full 6,500 rpm redline with a GM stock tune when it hits 165 f water and 75 f oil temp. Do you think GM would suggest this is OK if those temps were so low as to cause significantly raised wear, and give a 100,000 mile warranty? I don't think so, I believe GM thinks, as do I that those are operating temps.
Doesn't increase cooling? That's false. The volume of coolant when allowed to lose heat because of a lower temp thermostat will stay cooler longer when the vehicle is brought to rest, say at a stoplight, than with a higher temp thermostat. That's increased cooling no matter how it happens. In conjunction with earlier fan start, and fan running at higher percentages, your cooling is vastly increased.
Sorry, the article is fluff. Good basic facts, not very impressive conclusions.
More wear at lower temps? Where's the data? Remember, we're talking about running at 180 Vs. 200. That's only a 3% shift in temps (remember start at zero kelvin). If this was a problem then the poor engines would wear out or break after a few thousand cold starts, no matter what thermostat you are running. Again, it states wear from being below operating temp. Check it yourself, the C7Z sets the redline based on temps, oil and water. Mine goes to full 6,500 rpm redline with a GM stock tune when it hits 165 f water and 75 f oil temp. Do you think GM would suggest this is OK if those temps were so low as to cause significantly raised wear, and give a 100,000 mile warranty? I don't think so, I believe GM thinks, as do I that those are operating temps.
Doesn't increase cooling? That's false. The volume of coolant when allowed to lose heat because of a lower temp thermostat will stay cooler longer when the vehicle is brought to rest, say at a stoplight, than with a higher temp thermostat. That's increased cooling no matter how it happens. In conjunction with earlier fan start, and fan running at higher percentages, your cooling is vastly increased.
Sorry, the article is fluff. Good basic facts, not very impressive conclusions.
Instructor
Joined: Dec 2000
Posts: 118
Likes: 0
From: Everett, WA
I haven't measured this one specifically, but virtually all automotive thermostats take a good 25 degrees or so to go from their initial "crack open" "rated temperature" to fully open. So if you want a thermostat fully open by 195 degrees, you should look for a thermostat "rated at" 170 degrees.
The cooling system will not operate at maximum capacity until the thermostat is open 100%. You can crank on the fans, use water wetter and every other trick in the book, but if your thermostat is only 1/2 way open at a given temperature your cooling system is leaving 1/2 of its ability on the table.
Lingenfelter says the stock thermostat is rated at 212 degrees. Unless they're wrong, that means it isn't fully open until well over 230 degrees.
No, the thermostat does not set the ceiling for temps when the conditions vs. the capacity of your cooling system meet somewhere well above the thermostat's fully open temp (not rated temp). So if you're running in the 240-250 range, then no, a cooler thermostat isn't going to fix that--but it will take longer to get there so depending upon the length of the race it may still help.
If the issue you dislike is running in the 210-230 range under conditions you think the engine ought to be able to stay cooler, then yes, a cooler thermostat will help you. All by itself.
Of course setting the fan temps lower, etc, can help even more--particularly at lower speeds. But without replacing the thermostat you'll never get these engines to run cool.
Le Mans Master
Joined: Feb 2002
Posts: 9,883
Likes: 518
From: Bergen County NJ
To answer the OP - yes, they are now available through Lingenfelter - http://www.lingenfelter.com/mm5/merc...E#.VM7Z2U0tGK4
They also have 170* and 180* available..
Ant
They also have 170* and 180* available..
Ant
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
RUSS: nice link, however no facts presented, only opinions.
More wear at lower temps? Where's the data? Remember, we're talking about running at 180 Vs. 200. That's only a 3% shift in temps (remember start at zero kelvin). If this was a problem then the poor engines would wear out or break after a few thousand cold starts, no matter what thermostat you are running. Again, it states wear from being below operating temp. Check it yourself, the C7Z sets the redline based on temps, oil and water. Mine goes to full 6,500 rpm redline with a GM stock tune when it hits 165 f water and 75 f oil temp. Do you think GM would suggest this is OK if those temps were so low as to cause significantly raised wear, and give a 100,000 mile warranty? I don't think so, I believe GM thinks, as do I that those are operating temps.
Doesn't increase cooling? That's false. The volume of coolant when allowed to lose heat because of a lower temp thermostat will stay cooler longer when the vehicle is brought to rest, say at a stoplight, than with a higher temp thermostat. That's increased cooling no matter how it happens. In conjunction with earlier fan start, and fan running at higher percentages, your cooling is vastly increased.
Sorry, the article is fluff. Good basic facts, not very impressive conclusions.
More wear at lower temps? Where's the data? Remember, we're talking about running at 180 Vs. 200. That's only a 3% shift in temps (remember start at zero kelvin). If this was a problem then the poor engines would wear out or break after a few thousand cold starts, no matter what thermostat you are running. Again, it states wear from being below operating temp. Check it yourself, the C7Z sets the redline based on temps, oil and water. Mine goes to full 6,500 rpm redline with a GM stock tune when it hits 165 f water and 75 f oil temp. Do you think GM would suggest this is OK if those temps were so low as to cause significantly raised wear, and give a 100,000 mile warranty? I don't think so, I believe GM thinks, as do I that those are operating temps.
Doesn't increase cooling? That's false. The volume of coolant when allowed to lose heat because of a lower temp thermostat will stay cooler longer when the vehicle is brought to rest, say at a stoplight, than with a higher temp thermostat. That's increased cooling no matter how it happens. In conjunction with earlier fan start, and fan running at higher percentages, your cooling is vastly increased.
Sorry, the article is fluff. Good basic facts, not very impressive conclusions.
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
[QUOTE=Higgs Boson;1588866602]NASCAR, the pinnacle of automotive racing technology.
NASCAR went to fuel injection only 25 years after the automotive industry....wait, I thought street cars improve through racing tech, not the other way around....
Do you have any actual technological documented proof that higher coolant temperatures create more horsepower? Higher oil temps can make more power up to a point by reducing viscosity but coolant temps are better off as cold as you can get them.
Do you even race a car? You don't need a thermostat to get to Starbucks, on this point you are correct.
Heck I don't even go to Starbucks anymore because I don't want to catch diabetes and I hear they serve it up hot in every cup.[/QUOTE
Do you actually proof read your text before you hit send? Nascar, well I’m impressed to take a 358cuin push rod motors and have 43 cars run 9400 rpm’s for over 4 hours without any issues, week after week. When you build a motor from scratch and boost that I’ll listen. As far as I race cars, probably before you were born.
NASCAR went to fuel injection only 25 years after the automotive industry....wait, I thought street cars improve through racing tech, not the other way around....
Do you have any actual technological documented proof that higher coolant temperatures create more horsepower? Higher oil temps can make more power up to a point by reducing viscosity but coolant temps are better off as cold as you can get them.
Do you even race a car? You don't need a thermostat to get to Starbucks, on this point you are correct.
Heck I don't even go to Starbucks anymore because I don't want to catch diabetes and I hear they serve it up hot in every cup.[/QUOTE
Do you actually proof read your text before you hit send? Nascar, well I’m impressed to take a 358cuin push rod motors and have 43 cars run 9400 rpm’s for over 4 hours without any issues, week after week. When you build a motor from scratch and boost that I’ll listen. As far as I race cars, probably before you were born.