Proper engine temps for non emission engine
Thread Starter
Racer
Joined: Nov 2011
Posts: 319
Likes: 12
From: South Chase WI
Proper engine temps for non emission engine
I live in Wisconsin, no smog tests here for my 81 with the stock CCC engine.
Runs fine, 200 F on the gauge, a touch more with the a/c on. Fan works, clutch works.
Does it really need to run 200 F? What are the ramifications of a 160 thermostat? Was the 200 F design spec due to emissions or ??
Cooler running engine would be a nice thing I would think, perhaps quieter as the clutch would not lock up so much, less cabin heat, using the full capacity of the radiator. The marine counterpart 5.7 / 350 runs at 160 F, they run at a higher rpm and higher load though...
Hot topic I know, but ideas and opinions are appreciated.
Runs fine, 200 F on the gauge, a touch more with the a/c on. Fan works, clutch works.
Does it really need to run 200 F? What are the ramifications of a 160 thermostat? Was the 200 F design spec due to emissions or ??
Cooler running engine would be a nice thing I would think, perhaps quieter as the clutch would not lock up so much, less cabin heat, using the full capacity of the radiator. The marine counterpart 5.7 / 350 runs at 160 F, they run at a higher rpm and higher load though...
Hot topic I know, but ideas and opinions are appreciated.
Thread Starter
Racer
Joined: Nov 2011
Posts: 319
Likes: 12
From: South Chase WI
I NEVER expected to hear such a comment from you Mike. Blown away. LOL
Sorry, but when I use the search function, I get page after page of all and everything in between....anything with any of the terms "thermostat", "cooling", "design spec", etc shows up and I don't want to commit my week to trying to find out which of the hundreds of posts will yield a competent answer.
So I'll take the expected useless responses, and hope to find a few useful ones in the mix.
Unless you have a link to a search that yields useful info?
Sorry, but when I use the search function, I get page after page of all and everything in between....anything with any of the terms "thermostat", "cooling", "design spec", etc shows up and I don't want to commit my week to trying to find out which of the hundreds of posts will yield a competent answer.
So I'll take the expected useless responses, and hope to find a few useful ones in the mix.
Unless you have a link to a search that yields useful info?
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Thread Starter
Racer
Joined: Nov 2011
Posts: 319
Likes: 12
From: South Chase WI
Burning Brakes
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
My 67 327 sb use to run 170-180 all day and it felt good my 350sb runs at 195-210 its a daily driver but I feels it doesn't have that umph! and that's with a 190 thermostat but the heater works better than in the cooler 327.. I tried running it without a stat and a 160stat and heater never really warms up good IMO. I am also in the process of cutting a hole in the center of bumper similar to the early vettes in hope of going down a couple degrees. I removed the front impact bar/reservoir and it didn't make a noticeable difference in engine temps.
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Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
As the link above eludes to, for street-driven rigs, the proper 'operating temp' is the coolant temp which keeps the engine oil at 212f which quickly cooks out the moisture (condesate) that collects in the crankcase. Obviously, liquid water in the oil isn't good. At 212f, this water is quickly vaporized then removed via the PCV system. Engines that never reach operating temp (no thermostat, cars that take only short trips, etc) won't last as long.
The oil's temp typically runs 25-30f hotter than the coolant's temp,..so a coolant temp of 180 is pretty close for most apps. An oil temp gauge would come in handy here.
FWIW
The oil's temp typically runs 25-30f hotter than the coolant's temp,..so a coolant temp of 180 is pretty close for most apps. An oil temp gauge would come in handy here.
FWIW
Last edited by 73, Dark Blue 454; Sep 12, 2014 at 09:55 PM.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I just don't buy any story about oil having to be 212*F for the oil to be safe to run in the engine long term. The GM oil life monitoring systems use temperature de-rating factors below about 175*F and above about 265*F. So, it would seem that the GM testing found the engine would live a full life with the oil anywhere between those values. The oil life monitor would be using a 212*F lower-limit for the de-rating if it was necessary for the oil to reach 212*F before it was safe for long term operation in the engine.
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
you have a 1981 with the stock CCC, you use a 195* thermostat.
If you run your stock CCC temp too low it will never reach operating temp accoding to the CCC and never run closed loop. running in open loop constantly will hurt fuel mileage badly and you will also lose the benefits of having the CCC in the first place.
If you run your stock CCC temp too low it will never reach operating temp accoding to the CCC and never run closed loop. running in open loop constantly will hurt fuel mileage badly and you will also lose the benefits of having the CCC in the first place.
Safety Car
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From: San Antonio TX
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
totally correct.
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
I didn't see where it said that the moisture would never evaporate below 212 degrees F. This is what I saw related to that "This is a generalised statement and can vary with load and engine design but you can see why you want your oil over 212 degrees to boil out the moiture immediately!"
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
... and this from Mobil about how moisture gets in the oil: https://www.corvetteforum.com/forums...post1587807719
Question:
How Does Water Get in Motor Oil?
How does water get in the engine oil? Does it blow past the pistons or valves? Does water in the oil indicate the possibility of a blown head gasket?
-- Paul Lott, Bryans Road, MD
Answer:
Water can get into the oil two ways. You generally don't have to worry about one of the ways if you drive your car enough to burn off the water during normal driving. This drives off the moisture that simply comes from your engine breathing when it is not being used (cold air enters a hot engine and water condenses) and from combustion by-products. The second more destructive route is through a coolant leak due to a bad gasket, an engine crack, etc. This amount of moisture is generally going to cause serious engine issues including loss of power, oil sludging, etc. Consult your mechanic when in doubt.
Question:
How Does Water Get in Motor Oil?
How does water get in the engine oil? Does it blow past the pistons or valves? Does water in the oil indicate the possibility of a blown head gasket?
-- Paul Lott, Bryans Road, MD
Answer:
Water can get into the oil two ways. You generally don't have to worry about one of the ways if you drive your car enough to burn off the water during normal driving. This drives off the moisture that simply comes from your engine breathing when it is not being used (cold air enters a hot engine and water condenses) and from combustion by-products. The second more destructive route is through a coolant leak due to a bad gasket, an engine crack, etc. This amount of moisture is generally going to cause serious engine issues including loss of power, oil sludging, etc. Consult your mechanic when in doubt.
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Agreed that they (Mobil) worded it poorly. It is more an issue of the crankcase temperatures going from an elevated operating temperature to a lower temperature. The higher initial temperatures support a higher amount of moisture and when the air in the crankcase cools down some moisture that was in a gaseous state will condense into a liquid state.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Agreed that they (Mobil) worded it poorly. It is more an issue of the crankcase temperatures going from an elevated operating temperature to a lower temperature. The higher initial temperatures support a higher amount of moisture and when the air in the crankcase cools down some moisture that was in a gaseous state will condense into a liquid state.