Engine cooling / Thermostat question
Thread Starter
Instructor
Joined: Feb 2003
Posts: 164
Likes: 1
From: Houston Texas
Engine cooling / Thermostat question
I see that several thermostats are available for my car (1971 BB):
160, 180 and 195 F. Why that?
Why would I start cooling at 160? What are the benefits?
160, 180 and 195 F. Why that?
Why would I start cooling at 160? What are the benefits?
Race Director
Joined: Sep 2001
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From: Wellington, FL
St. Jude Donor '11 thru '25
I would suggest using the thermostat rating GM references. Using a 160 is too low IMO as it takes longer for the car to reach normal operating temp. When it doesn't reach it, condensation not burned off or evaporated can create problems for both the engine and exhaust system.
Pro
Joined: Mar 2015
Posts: 681
Likes: 31
From: Nebraska
I would suggest using the thermostat rating GM references. Using a 160 is too low IMO as it takes longer for the car to reach normal operating temp. When it doesn't reach it, condensation not burned off or evaporated can create problems for both the engine and exhaust system.
Team Owner
Joined: Jun 2000
Posts: 38,923
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From: Southbound
Cruise-In II Veteran
I would suggest using the thermostat rating GM references. Using a 160 is too low IMO as it takes longer for the car to reach normal operating temp. When it doesn't reach it, condensation not burned off or evaporated can create problems for both the engine and exhaust system.
Stock is 195.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
160 is good for short hard blasts, 1/4 mile runs or auto cross. I helps keep the oil from getting too hot and a bit more performance from a cooler intake manifold but for a street car 180 is perfect.
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Joined: Aug 2012
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Fuel burns more completely when its a bit on the warm side-by this I'm referring to intake charge temp-not actual liquid fuel temp. And, if youre running a quality full synthetic oil like Mobil 1 or Amsoil, you can't get the oil hot enough to break down. Oil temp has to approach 600F first. Conventional dino oil begins to break down at 260F-keep in mind that's oil temp not coolant temp.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
180*F was the operating temp specified for the Chevy V8 when it was designed.
195*F stat was installed to keep engine heat up so more hydrocarbons were burned off during combustion. This is what you need if you want to be "green".
195*F stat is REQUIRED for engines with ECM controllers, as the ECM's will stay in 'startup' mode until operating temp is reached. A 180*F stat is too cold to guarantee proper ECM operation.
160*F stat can be installed to ATTEMPT to reduce engine operating temps, when overheating is experienced. Operating the engine with a 160*F stat causes no harm. But, it may not help, either. The stat only sets the LOWEST possible operating temp for the engine. If the cooling system cannot maintain that temperature, temps will increase to what that cooling system is capable of maintaining.
195*F stat was installed to keep engine heat up so more hydrocarbons were burned off during combustion. This is what you need if you want to be "green".
195*F stat is REQUIRED for engines with ECM controllers, as the ECM's will stay in 'startup' mode until operating temp is reached. A 180*F stat is too cold to guarantee proper ECM operation.
160*F stat can be installed to ATTEMPT to reduce engine operating temps, when overheating is experienced. Operating the engine with a 160*F stat causes no harm. But, it may not help, either. The stat only sets the LOWEST possible operating temp for the engine. If the cooling system cannot maintain that temperature, temps will increase to what that cooling system is capable of maintaining.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 970
From: Tennessee/Rhode Island
180 for the street....forget 195 which as others have stated was more for emissions reasons than any thing else. Starting in the late 70's the L-82 with the bigger 882 heads and higher lift cam with more duration, had a heck of time passing emissions. GM ran a 195 thermostat attempting to raise the operating temp of the engine along with lean carb jetting, and reduced timing and my 78 L-82 routinely would run 225-230 with no AC and 235-240 with AC on (the demise of the L-82 after 1980 was mostly a failure to pass emissions). The thermostat only controls the minimum temp and effects how long the engine takes to get to full operating temperature but the cooling system components/efficiency controls the actual full /normal operating temperature on warm days.
Race Director
Joined: Apr 2007
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From: South Western Ontario
Like what? The claims that a 160* or 180* thermostat will keep a fuel injected engine out of closed loop operation are complete BS. Every GM fuel injected vehicle goes to close loop by about 115*F at the highest. The newer stuff does it much sooner, about as quickly after a start as possible no matter how cold the engine is.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 970
From: Tennessee/Rhode Island
Like what? The claims that a 160* or 180* thermostat will keep a fuel injected engine out of closed loop operation are complete BS. Every GM fuel injected vehicle goes to close loop by about 115*F at the highest. The newer stuff does it much sooner, about as quickly after a start as possible no matter how cold the engine is.
I have a 2001 FI 3.1 V6 Pontiac Grand Prix that has a 195 thermostat from the factory and the typical operating temp is 180-185, not 195+, that you would think....car runs perfectly at that temp (even lower in the dead of winter with the heater on) and gets 28 MPG on the highway @80 mph. And oh yea, coming on 180,000 miles and never burns an oz of oil between 5,000 mile oil changes, for those that profess that cold temps promote engine wear.
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
Like what? The claims that a 160* or 180* thermostat will keep a fuel injected engine out of closed loop operation are complete BS. Every GM fuel injected vehicle goes to close loop by about 115*F at the highest. The newer stuff does it much sooner, about as quickly after a start as possible no matter how cold the engine is.
I wonder how many cars in Minnesota get to 195 degrees in the winter.all this stuff about lower temp thermostats causing damage is hogwash. I've had several fuel injected cars Tha went over 300k miles with zero issues.the manufacturers tell people this stuff for legal reasons and even their mechanics buy it. If you live in a hot climate run a 160 if your summer is more moderate 180. Chevrolet used to recommend different thermostats and oil viscosity based on what time of year and where you lived
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
I suspect that the actual temperature the ECM's are looking for is probably nearer the 180*F number. But, if you have a 180* stat, that may...or may not...get the job done. Sounds like it hasn't been a problem for you. But, I wouldn't want everyone reading this thread to ignore the FACT that a specified temp needs to be achieved for electronic engine controlled systems to get out of 'start-up' mode.
Race Director
Joined: Apr 2007
Posts: 11,150
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From: South Western Ontario
I suspect that the actual temperature the ECM's are looking for is probably nearer the 180*F number. But, if you have a 180* stat, that may...or may not...get the job done. Sounds like it hasn't been a problem for you. But, I wouldn't want everyone reading this thread to ignore the FACT that a specified temp needs to be achieved for electronic engine controlled systems to get out of 'start-up' mode.
I've looked at dozens and dozens of tunes and have yet to find one set even close to 160* where a 160* stat would keep it out of closed loop yet alone even higher where a 180* thermostat would cause a problem. It's nothing but a stupid theory spread by people who don't know any better.