Winter vs summer thermostats
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,692
Likes: 29
From: Texas
Winter vs summer thermostats
How many change their thermostats winter to summer. Now that things are cooler and with a good 4 core radiator, with a low temp thermostat, engine does want to warm up enough until I have some good miles on the beltway in Houston. In summer, the thermostat and the good radiator keep the car nicely under 190* except for continued stop and go bumper to bumper traffic. Thinking about going to a higher temp thermostat now.
Drifting
Joined: Oct 2010
Posts: 1,972
Likes: 6
From: Chester Virginia
Mine is 195 degree spec for my 76 but it's too much heat in the summer so I started with a 180 degree thermostat and when it was 95 F outside on an interstate it got back to where it was or close to it so I went to a 165 F thermostat and that worked well. I know all modern cars are just under 200 but the Vette just feels better to me with all the footwell heat anyway and I put a valve in to stop summer heat to the heater that I reverse in winter. I have not taken the 165 degree thermostat out yet and have driven the car in the fifties for temp with the t tops out which I never put in and just turned the heater on. It runs dead on at 165 now and did in the summer.
It may be wrong but as of right now I am planning to leave it at 165. At most I think I'd go back to winter 180F thermostat.
Don't know if there are any long term consequences but so far it's working for me. The heater on my 76 will blow you outta there.
It seems to me that back before all the modern stuff many if not most cars did run at 165 then the EPA got involved....anybody remember?
Lance P.
It may be wrong but as of right now I am planning to leave it at 165. At most I think I'd go back to winter 180F thermostat.
Don't know if there are any long term consequences but so far it's working for me. The heater on my 76 will blow you outta there.
It seems to me that back before all the modern stuff many if not most cars did run at 165 then the EPA got involved....anybody remember?
Lance P.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
before the newer emission requirements and higher operating temps on the motors (with the 195º t-stats) the common t-stat was a 180º.
Assuming the cooling system is good enough to keep operating temps at the same level as the selected t-stat, a 160º or 165º t-stat is too low as this doesn't allow the motor to get hot enough to burn off excess fumes and contaminants.
If you still need to have your car pass emission tests in your state than you are best off going back to the 195º t-stat and if it's too much heat in the cabin for you you can install a coolant cut-off valve in the coolant line before the heater box. This would cut off coolant getting to the heater box and reducing the heat level in the cabin
If you don't want to go back to your factory spec'd 195º t-stat at least bring it up to a 180º unit. In the long term your motor will appreciate it.
Assuming the cooling system is good enough to keep operating temps at the same level as the selected t-stat, a 160º or 165º t-stat is too low as this doesn't allow the motor to get hot enough to burn off excess fumes and contaminants.
If you still need to have your car pass emission tests in your state than you are best off going back to the 195º t-stat and if it's too much heat in the cabin for you you can install a coolant cut-off valve in the coolant line before the heater box. This would cut off coolant getting to the heater box and reducing the heat level in the cabin
If you don't want to go back to your factory spec'd 195º t-stat at least bring it up to a 180º unit. In the long term your motor will appreciate it.
Drifting
Joined: Oct 2010
Posts: 1,972
Likes: 6
From: Chester Virginia
I've been wondering if I should go back to the 180. thanks for the advice. I have it and it was used a week and have the gasket...may put it in before I drive it. I have the ball valve in line to cut the heater core off in summer already. I noticed that the smell in the garage when I come home from a ride was a little different and the only thing done was the 165. I just looked up my 66 Pontiac Tempest 326 v 8 and it looks like that was a 180 though a 165 was offered. I'm not going back to the 195.
Lance P.
Lance P.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
I installed ONE thermostat in my vette... a 180 degree unit for under $7. It keeps the engine at close to 190 F (max) reliably. I may 'nudge' 200 in heavy stop-and-go but that is the exception and it 'cools' to 190 quickly once I am getting good circulation (car moving). Probably installed it back around 2000 when I installed the new Performer intake. Install your choice of thermo' and ENJOY the C3!!!
In Tehas, I'd probably STILL choose a 180 degree unit.
NOTE: Installed my thermo' in Tampa, FL.
In Tehas, I'd probably STILL choose a 180 degree unit.
NOTE: Installed my thermo' in Tampa, FL.
Last edited by TedH; Nov 15, 2011 at 07:42 PM.
Racer
Joined: Mar 2008
Posts: 434
Likes: 0
From: Triangle Area NC
I think a thermo defines how cold an engine gets not how hot it gets.
Dunno what's optimum, but I know hot engines ping more easily than cooler ones. Seat of pants, 180 seems a good compromise
John
Dunno what's optimum, but I know hot engines ping more easily than cooler ones. Seat of pants, 180 seems a good compromise
John
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
It should still get up to your current operating temp just as fast as it would with a higher temp thermostat.
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How many change their thermostats winter to summer. Now that things are cooler and with a good 4 core radiator, with a low temp thermostat, engine does want to warm up enough until I have some good miles on the beltway in Houston. In summer, the thermostat and the good radiator keep the car nicely under 190* except for continued stop and go bumper to bumper traffic. Thinking about going to a higher temp thermostat now.
Tech Contributor
Joined: Jun 2004
Posts: 20,869
Likes: 961
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Ran a 99* track day at Topeka last summer (amongst other track days). Between the correct ignition timing and A/F ratio, and the DeWitts radiator, the temps were right where I wanted them to be.
This 195 degree crap works for me.
Tech Contributor
Joined: Jun 2004
Posts: 20,869
Likes: 961
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I'm surprised you're having this problem in Houston. In Massachusetts i need to run a 195 in Winter to keep warm. For some reason a 180 doesn't cut it. Under light load conditions and 20 degree weather the heater core dissipates most of the engine heat generated, so it is possible to run lower temps than the T-stat rating.
Last edited by 69427; Nov 15, 2011 at 11:48 PM. Reason: Spelling correction and clarified question.
Tech Contributor
Joined: Jun 2004
Posts: 20,869
Likes: 961
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
before the newer emission requirements and higher operating temps on the motors (with the 195º t-stats) the common t-stat was a 180º.
Assuming the cooling system is good enough to keep operating temps at the same level as the selected t-stat, a 160º or 165º t-stat is too low as this doesn't allow the motor to get hot enough to burn off excess fumes and contaminants.
If you still need to have your car pass emission tests in your state than you are best off going back to the 195º t-stat and if it's too much heat in the cabin for you you can install a coolant cut-off valve in the coolant line before the heater box. This would cut off coolant getting to the heater box and reducing the heat level in the cabin
If you don't want to go back to your factory spec'd 195º t-stat at least bring it up to a 180º unit. In the long term your motor will appreciate it.
Assuming the cooling system is good enough to keep operating temps at the same level as the selected t-stat, a 160º or 165º t-stat is too low as this doesn't allow the motor to get hot enough to burn off excess fumes and contaminants.
If you still need to have your car pass emission tests in your state than you are best off going back to the 195º t-stat and if it's too much heat in the cabin for you you can install a coolant cut-off valve in the coolant line before the heater box. This would cut off coolant getting to the heater box and reducing the heat level in the cabin
If you don't want to go back to your factory spec'd 195º t-stat at least bring it up to a 180º unit. In the long term your motor will appreciate it.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
Team Owner
Joined: Aug 1999
Posts: 30,995
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From: Ontario
Barry,
It's been a long time but I still enjoy your web site. I see you keep it up-to-date.
Paul
http://lbfun.com/Corvette/Tech/vettetech.html
It's been a long time but I still enjoy your web site. I see you keep it up-to-date.
Paul
http://lbfun.com/Corvette/Tech/vettetech.html
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
Hey Paul
hope all is well with you!
Actually, I rarely update the site anymore, mostly just try to make sure it stays up and running and working more than anything else.
It does need a good updating if I ever get the spare time and motivation.
hope all is well with you!
Actually, I rarely update the site anymore, mostly just try to make sure it stays up and running and working more than anything else.
It does need a good updating if I ever get the spare time and motivation.
Drifting
Joined: Apr 2003
Posts: 1,323
Likes: 2
From: Castle Hills Texas
Thermostats in proper working order, control only the minimum operating temperature at which engine coolant is allowed to heat. A properly operating thermostat has absolutely nothing to do with how hot the engine becomes.
There always seems to be some confusion on this.
There always seems to be some confusion on this.
Drifting
Joined: Oct 2010
Posts: 1,972
Likes: 6
From: Chester Virginia
Yep...that's so. In my case I put my 180 degree in this morning and after experimenting between 195 as specified all the way down to 165 all summer I decided as someone here also said that I'm going to run the 180 degree and it's in and will be in next summer as well.
Lance P.
Lance P.
