Replaced my stat but ??
Le Mans Master
Joined: Mar 2008
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From: Oxford MA-----You just lost the game!!!!
Pro
Joined: Oct 2009
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From: Calgary Alberta
So I was in there today on my 74 l82 replacing gaskets on my new water pump with some rtv gasket maker replaced my pulleys to alluminum. Then replaced my stat with the stant 180. When I took the old one out I was surprised it was a 160 stat. Is this normal to run a 160 stat. I thought the original was 190 and I was doing a good thing by going to a 180.
What temperature stats do you guys have
What temperature stats do you guys have
With a 160 stat the air blowing through the heater to the car gets only warm, the 180 stat makes the air warmer and the 190 makes it quite hot.
Therefore with nothing else changed in the system the hotter thermostat will allow the coolant/anti-freeze to get hotter. Also, other experiences that I have had that have bearing on this is if the thermostat fails open in the middle of winter you will have little or no heat in the car and the temperature gauge will never reach normal operating temperature, thus the engine would also be running colder than normal. The rest of the system is functioning fine just the thermostat is stuck open.
On the cooling side in the summer, once the thermostat is fully open then the rest of the cooling system is responsible for keeping the engine cool. Think about what happens when your fan belt breaks in a traffic jam on a hot day? A cooler thermostat won't help that situation.
With this in mind I put a 180 thermostat in my engine as I believe that an engine that runs a little hotter provides better performance and it also provides better fuel efficiency overall. However that is JMHO.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Yes an extreme ambient temp will make a big difference.
The temperature should never stabilize at a temperature lower than the tstat rated temp. +/- of course.
IF YOUR SYSTEM CAPACITY (large enough rad , fans etc) is adequate, the coolant temp will remain at the tstat temp +/-.
BTW, a 180° tstat is NOT fully open at 180°.
The temperature should never stabilize at a temperature lower than the tstat rated temp. +/- of course.
IF YOUR SYSTEM CAPACITY (large enough rad , fans etc) is adequate, the coolant temp will remain at the tstat temp +/-.
BTW, a 180° tstat is NOT fully open at 180°.
How wrong you are....
If you switch from a 190* stat to a 160* stat and your temps are still running the same 200*+ then your cooling system sucks and is so marginal it's barely capable of cooling the engine.
And for those that don't get it, a thermostat is a linear device. It will change from full closed to full open over a range of temperatures. For example, a 160* stat might be fully closed at 160*, just begin to lift off the seat at 161* and take until 175* to be fully open.
So, you'll never run at 160* with a 160* thermostat because the coolant has to get hot enough that it will actually open and allow coolant flow. On a cold day, you might run 165* with the thermostat just open a bit. On a hot day, you might run >170* before the thermostat opens enough to allow the coolant flow required to hold the temperature steady.
The vehicles I own run within the typical thermostat operating band as long as there is enough airflow across the rad. I say enough airflow because they are electric fan cooled which means they will run hotter when stopped or driving slow until the fans turn on. On the highway, they are always 5* to 10* above the thermostat rated temperature depending on the ambient air temperature.
If you switch from a 190* stat to a 160* stat and your temps are still running the same 200*+ then your cooling system sucks and is so marginal it's barely capable of cooling the engine.
And for those that don't get it, a thermostat is a linear device. It will change from full closed to full open over a range of temperatures. For example, a 160* stat might be fully closed at 160*, just begin to lift off the seat at 161* and take until 175* to be fully open.
So, you'll never run at 160* with a 160* thermostat because the coolant has to get hot enough that it will actually open and allow coolant flow. On a cold day, you might run 165* with the thermostat just open a bit. On a hot day, you might run >170* before the thermostat opens enough to allow the coolant flow required to hold the temperature steady.
The vehicles I own run within the typical thermostat operating band as long as there is enough airflow across the rad. I say enough airflow because they are electric fan cooled which means they will run hotter when stopped or driving slow until the fans turn on. On the highway, they are always 5* to 10* above the thermostat rated temperature depending on the ambient air temperature.
because that is how it works. The outlet water temp at the bottom of the heat exchanger i.e. radiator, should be less than 160* for a 160* tstat and less than 180* for a 180* tstat and so on. I had a 160* in my engine at one point and it ran at 160*-ish most of the time. On a hot day it ran 20* higher. Why? Because my radiator didn't have the capacity to reject the heat at higher ambient air temps and the outlet temp of the rad was therefore higher and this higher coolant temperture went back into the engine keeping the tstat fully open. Had my temps risen to a constant 240* or whatever, I would have bought a radiator with a larger capacity e.g. aluminium. Hey, isn't that what most say in here for overheating problems? Bigger radiator to lower your radiator outlet temperature!!!
Advanced
Joined: May 2011
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From: Pearland Tx
This is an interesting discussion so lets add another point. For those of us with electric fans, where do you have your fans come on, at 160 with a 160 stat, 180 with a 180 stat or does the stat matter?
I have my first fan come on at 180 and the second one at 195 and my stat is 180. What are others doing?
I have my first fan come on at 180 and the second one at 195 and my stat is 180. What are others doing?
Race Director
Joined: Apr 2007
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From: South Western Ontario
This is an interesting discussion so lets add another point. For those of us with electric fans, where do you have your fans come on, at 160 with a 160 stat, 180 with a 180 stat or does the stat matter?
I have my first fan come on at 180 and the second one at 195 and my stat is 180. What are others doing?
I have my first fan come on at 180 and the second one at 195 and my stat is 180. What are others doing?
The fan turn-off needs to be about 10* above the thermostat rating. 190* off is about the lowest fan turn-off temperature you should be using with a 180* stat. You might be able to get away with a little less if you have the sensor in the rad but the coolant right by the rad inlet really isn't much cooler than it is in the block.
Also, if you have 2 fans then using the 3-relay wiring method to give 2-speeds is a really slick way to run them. It really keeps the noise down most of the time.
Team Owner
Joined: Jan 2006
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From: Crossville TN
Electric fan temp relay should be set at least 10*F higher than the thermostat setting. If your car uses a 195*F stat, the fan switch should not turn on until at least 205*F. 210-215*F would probably be better.
You don't want the fans coming on until the operating temp is somewhat above the rating of the stat. The thermostat sets the minimum water temp and the electric fans attempt to establish the maximum water temp. Actual max. temps will be somewhat above the fan-ON setting, but will likely be within 10*F of the fan switch temp setting.
You don't want the fans coming on until the operating temp is somewhat above the rating of the stat. The thermostat sets the minimum water temp and the electric fans attempt to establish the maximum water temp. Actual max. temps will be somewhat above the fan-ON setting, but will likely be within 10*F of the fan switch temp setting.
