Thernostat
Safety Car
Joined: May 2001
Posts: 4,757
Likes: 1,647
From: Fairfax Virginia
I run a high compression 427 in my 1968 C3 and have learned volumes about making a Corvette run a bit cooler. Running with no TS is clearly a no-no any time of the year. They do make small plates to restrict the flow if you do not have or want a T/S. Currently my car has a Be Cool Radiator with two SPAL fans in a shroud on the radiator. The coolant in my car is 100% EVANS NPG and with the current radiator system it worked just fine, I would occasionally see over 230* but not often and I have no detonation or pinging that I can hear.
Recently I blew up my last Fan Control System so I bought the latest version of the DeRale 16795. This "Pulse Width Modulation" controller is different from all others I have seen and really seems to work well. When the fans come of they start off at 50% speed and slowly ramp up as the temperature rises. This means I don't have the power spikes where two fans turn on at 100%, instead it is much more gradual and the noise is reduced considerably. I used to have both fans activate sequentially but the noise was ridiculous and the spikes caused the voltage to fluctuate making the other accessories. The DeRale Control Module is designed to adjust the electric fan speed PWM to maintain the "optimal" engine temperature. You are the one who determines when it goes to 100% on both fans by adjusting a potentiometer inside the controller body. I have mine set to about 220 before it goes to 100% full power to the fans. This way most of the time I only hear a bit of fan noise and not two screaming fans pulling close to 50 amps wide open.
I had a question regarding whether my SPAL fans would work with a PWM controller so I called DeRale's Tech Support. I got a young man who had an incredible amount of knowledge regarding this system. He told me that the SPAL fans would work just fine with their controller. I asked about the mounting point for the sensor and he found out I had the old style sensor that went thru the radiator and clamped on. There was a newer version of a sensor that mounted directly on the aluminum tanks on the radiator and it was better. The tech sent me at no charge the new sensor and made sure I knew how to install it and exactly where. I was very impressed with their product support.
One important reason for getting your engine to warm up completely using a thermostat is to get your engines oil hot enough to boil out the condensation that occurs normally. If you never get the oil to rid itself of water then your engine will have issues with water in your oil after a few cycles. I installed a Perkins Diesel in my 36' boat while in college. My first attempt was using the open loop seawater to cool it but it never warmed up to operating temperatures because it had no thermostat. This led me to my second attempt which was with a closed loop cooling system. The closed loop used coolant like in a car and had a separate pump bringing seawater going through a heat exchanger and back to the sea by way of exhaust system. Using the closed loop actually increased the operating temp and made the engine run more efficiently using less fuel and producing a LOT less Black smoke. That lesson taught me a lot and it does cross over to apply to cars as well.
Thanks to resdoggie for that great paper from Clemson, well worth the read and I would also say "Thank You" for bringing a little light into this discussion.
Best regards
Recently I blew up my last Fan Control System so I bought the latest version of the DeRale 16795. This "Pulse Width Modulation" controller is different from all others I have seen and really seems to work well. When the fans come of they start off at 50% speed and slowly ramp up as the temperature rises. This means I don't have the power spikes where two fans turn on at 100%, instead it is much more gradual and the noise is reduced considerably. I used to have both fans activate sequentially but the noise was ridiculous and the spikes caused the voltage to fluctuate making the other accessories. The DeRale Control Module is designed to adjust the electric fan speed PWM to maintain the "optimal" engine temperature. You are the one who determines when it goes to 100% on both fans by adjusting a potentiometer inside the controller body. I have mine set to about 220 before it goes to 100% full power to the fans. This way most of the time I only hear a bit of fan noise and not two screaming fans pulling close to 50 amps wide open.
I had a question regarding whether my SPAL fans would work with a PWM controller so I called DeRale's Tech Support. I got a young man who had an incredible amount of knowledge regarding this system. He told me that the SPAL fans would work just fine with their controller. I asked about the mounting point for the sensor and he found out I had the old style sensor that went thru the radiator and clamped on. There was a newer version of a sensor that mounted directly on the aluminum tanks on the radiator and it was better. The tech sent me at no charge the new sensor and made sure I knew how to install it and exactly where. I was very impressed with their product support.
One important reason for getting your engine to warm up completely using a thermostat is to get your engines oil hot enough to boil out the condensation that occurs normally. If you never get the oil to rid itself of water then your engine will have issues with water in your oil after a few cycles. I installed a Perkins Diesel in my 36' boat while in college. My first attempt was using the open loop seawater to cool it but it never warmed up to operating temperatures because it had no thermostat. This led me to my second attempt which was with a closed loop cooling system. The closed loop used coolant like in a car and had a separate pump bringing seawater going through a heat exchanger and back to the sea by way of exhaust system. Using the closed loop actually increased the operating temp and made the engine run more efficiently using less fuel and producing a LOT less Black smoke. That lesson taught me a lot and it does cross over to apply to cars as well.
Thanks to resdoggie for that great paper from Clemson, well worth the read and I would also say "Thank You" for bringing a little light into this discussion.
Best regards
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
'resdoggie'
I am well aware of the wax pellet in a thermostat and how it works.
I understand and know that the thermostat will do what it is told to do by the coolant temperature making contact with it. The coolant temp is providing what is needed so the thermostat will do as needed due to the temp of the coolant. Just like about every gauge on a car. They only do what they are told by the sensor or cable providing that information to make it do what it is being told to do. SO in my way of thinking it cannot think on its own like it has a brain. Heck even a current cars computer module...and as you know it is not a brain and can think all by itself. It is getting information and applies a program embedded to it to make the systems work.
Simply put like 'lars' mentioned. If the thermostat is fully open and your car is running above 200+ degrees...like 210, 220, or 230 degrees.
Changing to a 160 thermostat is not going to change jack squat. It still will run at that temp again under the same conditions. Because once the thermostat is fully open it is no longer able to regulate anything because it cannot enlarge the orifice that the coolant is flowing through to increase more water flow. Thus it cannot control the maximum coolant temperature like 'lars' wrote.
This is assuming that the coolant temperature sensor is correct. Because I have had some that when the temp got to certain point the temp gauge 'freaked' out and would peg the temp gauge but the coolant was not as hot as the gauge was showing. This was verified with racing temp gauge mentioned in another thread dealing with a coolant temp issue.
DUB
I am well aware of the wax pellet in a thermostat and how it works.
I understand and know that the thermostat will do what it is told to do by the coolant temperature making contact with it. The coolant temp is providing what is needed so the thermostat will do as needed due to the temp of the coolant. Just like about every gauge on a car. They only do what they are told by the sensor or cable providing that information to make it do what it is being told to do. SO in my way of thinking it cannot think on its own like it has a brain. Heck even a current cars computer module...and as you know it is not a brain and can think all by itself. It is getting information and applies a program embedded to it to make the systems work.
Simply put like 'lars' mentioned. If the thermostat is fully open and your car is running above 200+ degrees...like 210, 220, or 230 degrees.
Changing to a 160 thermostat is not going to change jack squat. It still will run at that temp again under the same conditions. Because once the thermostat is fully open it is no longer able to regulate anything because it cannot enlarge the orifice that the coolant is flowing through to increase more water flow. Thus it cannot control the maximum coolant temperature like 'lars' wrote.
This is assuming that the coolant temperature sensor is correct. Because I have had some that when the temp got to certain point the temp gauge 'freaked' out and would peg the temp gauge but the coolant was not as hot as the gauge was showing. This was verified with racing temp gauge mentioned in another thread dealing with a coolant temp issue.
DUB
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
'resdoggie'
I am well aware of the wax pellet in a thermostat and how it works. I'm not doubting that but most people don't hence my lengthy posts which are not directed at you in particular but the reader.
I understand and know that the thermostat will do what it is told to do by the coolant temperature making contact with it. Yes but the ts is also controlling the coolant temp by modulating the valve's opening/closing i.e. controlling flow rate. Kinda like the chicken and egg analogy. The coolant temp is providing what is needed so the thermostat will do as needed due to the temp of the coolant. Just like about every gauge on a car. They only do what they are told by the sensor or cable providing that information to make it do what it is being told to do. SO in my way of thinking it cannot think on its own like it has a brain. Heck even a current cars computer module...and as you know it is not a brain and can think all by itself. It is getting information and applies a program embedded to it to make the systems work. There's a difference between a sensor and a gauge and a controller. The ts is not a gauge, not a sensor per se but is a controller that responds to input i.e. coolant temperature. Don't take the 'brain' reference literally please. But an 'ecu' of modern cars is like a brain because it makes decisions (like adjusting afr, controls abs braking, etc) on engine/chassis management i.e. controls the controllers from feedback of the sensors and visually to the driver through gauges and dummy lights. But that's my way of thinking. The only human input is pressing on the gas/brake and that input goes through the ecu.
Simply put like 'lars' mentioned. If the thermostat is fully open and your car is running above 200+ degrees...like 210, 220, or 230 degrees. Yeah, you have a cooling issue. But engine's do not find a happy operating temp on their own i.e. no input from the ts, as has been stated by some. That would be a coolant system design failure. Engineer's don't leave this to 'chance' when it's easily corrected by a ts, rad capacity. Again, that's why our cars have ts's to also control optimum or maximum engine temp within a few degrees of the ts rating.
Changing to a 160 thermostat is not going to change jack squat. Yep. It still will run at that temp again under the same conditions. Yep. Because once the thermostat is fully open it is no longer able to regulate anything because it cannot enlarge the orifice that the coolant is flowing through to increase more water flow. Thus it cannot control the maximum coolant temperature like 'lars' wrote. Yep, because there is a cooling issue for this to happen. This doesn't happen in a properly functioning cooling system. Your ts is not fully open at normal operating temp. If its fully open, you probably have a cooling issue in conjunction with a higher than normal engine temp. But you can make your car run at 160*F by modifying your cooling system capacity.
This is assuming that the coolant temperature sensor is correct. Because I have had some that when the temp got to certain point the temp gauge 'freaked' out and would peg the temp gauge but the coolant was not as hot as the gauge was showing. This was verified with racing temp gauge mentioned in another thread dealing with a coolant temp issue.
DUB
I am well aware of the wax pellet in a thermostat and how it works. I'm not doubting that but most people don't hence my lengthy posts which are not directed at you in particular but the reader.
I understand and know that the thermostat will do what it is told to do by the coolant temperature making contact with it. Yes but the ts is also controlling the coolant temp by modulating the valve's opening/closing i.e. controlling flow rate. Kinda like the chicken and egg analogy. The coolant temp is providing what is needed so the thermostat will do as needed due to the temp of the coolant. Just like about every gauge on a car. They only do what they are told by the sensor or cable providing that information to make it do what it is being told to do. SO in my way of thinking it cannot think on its own like it has a brain. Heck even a current cars computer module...and as you know it is not a brain and can think all by itself. It is getting information and applies a program embedded to it to make the systems work. There's a difference between a sensor and a gauge and a controller. The ts is not a gauge, not a sensor per se but is a controller that responds to input i.e. coolant temperature. Don't take the 'brain' reference literally please. But an 'ecu' of modern cars is like a brain because it makes decisions (like adjusting afr, controls abs braking, etc) on engine/chassis management i.e. controls the controllers from feedback of the sensors and visually to the driver through gauges and dummy lights. But that's my way of thinking. The only human input is pressing on the gas/brake and that input goes through the ecu.
Simply put like 'lars' mentioned. If the thermostat is fully open and your car is running above 200+ degrees...like 210, 220, or 230 degrees. Yeah, you have a cooling issue. But engine's do not find a happy operating temp on their own i.e. no input from the ts, as has been stated by some. That would be a coolant system design failure. Engineer's don't leave this to 'chance' when it's easily corrected by a ts, rad capacity. Again, that's why our cars have ts's to also control optimum or maximum engine temp within a few degrees of the ts rating.
Changing to a 160 thermostat is not going to change jack squat. Yep. It still will run at that temp again under the same conditions. Yep. Because once the thermostat is fully open it is no longer able to regulate anything because it cannot enlarge the orifice that the coolant is flowing through to increase more water flow. Thus it cannot control the maximum coolant temperature like 'lars' wrote. Yep, because there is a cooling issue for this to happen. This doesn't happen in a properly functioning cooling system. Your ts is not fully open at normal operating temp. If its fully open, you probably have a cooling issue in conjunction with a higher than normal engine temp. But you can make your car run at 160*F by modifying your cooling system capacity.
This is assuming that the coolant temperature sensor is correct. Because I have had some that when the temp got to certain point the temp gauge 'freaked' out and would peg the temp gauge but the coolant was not as hot as the gauge was showing. This was verified with racing temp gauge mentioned in another thread dealing with a coolant temp issue.
DUB
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
And again, why would anyone want to slow down the coolant flow, throw away the ts, loosen rad cap, etc. in a perfectly functioning cooling system unless there was an actual cooling problem and they did this because they were too cheap to fix the root problem or just plain stupid.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
This is getting ridiculous. I am not taking any and all of your responses to be a direct attack at me in any way. It is..as it should be... a way for information to be expressed.
Obviously I did not wrote it out well enough to make it clear.
I never wrote a sensor and gauge and a controller are all the same. A sensor and a controller i.e. the thermostat in this case are the same thing In my opinion it is. WHY? because a coolant temperature sensor in the coolant system is controlled by the temperature of the coolant to preform a specific task IF that sensor provides an OHM value to make a gauge work..,,,and that OHM value is set to a specific coolant temperature made in the sensor to correspond to the gauge value you will see....then IT is a controller. The ONLY difference ( that I can see) is that the temperature sensor and gauge are not all together in one component....unlike the sensor in the thermostat that actually makes the valve move ...BUT the principle of what IT DOES is the exact same. It is getting information from the coolant to get the gauge to go to what it will tell you the temp is....and the wax in the thermostat is being heated.....thus changing it state to make the valve open or close or do whatever it is being told to do from the temperature of the coolant
We think differently on what we feel a computer is in regards to it having brain. It can only perform a task that it is programed to do and will not nor can not do it without outside information being sent to it for it to make a decision on what type of response it will make due to the information it is given. A computer cannot turn on cooling fans unless it has been told to do so...and this goes for every aspect of a cars computer. The input information for it to make a response has to be provided for it to do so. The human brain is different....if you see stop sign while driving you know to stop...but some people choose to run it and that is a conscience decision even though they know they are supposed to stop at it. A cars computer cannot do what it wants when it feels like it.
DUB
Obviously I did not wrote it out well enough to make it clear.
I never wrote a sensor and gauge and a controller are all the same. A sensor and a controller i.e. the thermostat in this case are the same thing In my opinion it is. WHY? because a coolant temperature sensor in the coolant system is controlled by the temperature of the coolant to preform a specific task IF that sensor provides an OHM value to make a gauge work..,,,and that OHM value is set to a specific coolant temperature made in the sensor to correspond to the gauge value you will see....then IT is a controller. The ONLY difference ( that I can see) is that the temperature sensor and gauge are not all together in one component....unlike the sensor in the thermostat that actually makes the valve move ...BUT the principle of what IT DOES is the exact same. It is getting information from the coolant to get the gauge to go to what it will tell you the temp is....and the wax in the thermostat is being heated.....thus changing it state to make the valve open or close or do whatever it is being told to do from the temperature of the coolant
We think differently on what we feel a computer is in regards to it having brain. It can only perform a task that it is programed to do and will not nor can not do it without outside information being sent to it for it to make a decision on what type of response it will make due to the information it is given. A computer cannot turn on cooling fans unless it has been told to do so...and this goes for every aspect of a cars computer. The input information for it to make a response has to be provided for it to do so. The human brain is different....if you see stop sign while driving you know to stop...but some people choose to run it and that is a conscience decision even though they know they are supposed to stop at it. A cars computer cannot do what it wants when it feels like it.
DUB
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Lars' statement is false but believed by many. The ts will only fully open and stay open when the coolant entering the block hasn't cooled enough to reduce the block coolant temp exiting at the ts. A precarious situation to be in because now the coolant temperature is dictated by the ambient air temperature. As ambient increases so will the coolant temp entering the block eventually leading to overheating and engine failure if not corrected. Car makers design engines to run at a certain normal operating temp for the conditions expected by the end user and the way they achieve this is to install a ts. Read a GM service manual and see what they have to say about the purpose of a ts. It's not just about quicker warm up.
I was chastised for explaining this.
I tried to explain tstat modulating control to this crowd over 10 years ago and absolutely NO ONE would understand it.
They were all hung up on this minimum temp thing.
I had the privilege of discussing this with an actual tstat design engineer many years ago and with his information have never ever had cooling issues that could not be resolved.
Glad to see you're finally converting some.
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