Thermostat Temp...Which One?
08-06-2018, 05:12 PM
#1
2nd Gear Member
Thread Starter
Join Date: Mar 2015
Location: Oregon
Posts: 188
Thermostat Temp...Which One?
Sorry if this has been asked before...after sitting for over a year and a half we are *finally* stepping forward on replacing the intake manifold, coils and plugs on our 2001 Vortech charged GT...so excited. We ordered the Ford Performance PI intake manifold, genuine Motorcraft DG508 COPs and SP413 plugs. While the manifold is out we are also replacing the fuel injector seals and putting in a new cooling system thermostat and thermostat seal. My question is which thermostat to get. I think the thermostat that’s in there now was one I put in several years ago because the engine took forever to warm up. I don’t remember which one I got...it would be whatever pulled up at the LAP store as the stock temp, but it still seems to take awhile to warm up. So...what do you guys/gals recommend? 180F? 190F? 192F? 195F, or...? I’m in Oregon so winters are mild (usually some days of freezing temps but just barely at that), and summertime gets hot but rarely into triple digits and typically only bursts into the 90s.
Thanks.
Thanks.
08-06-2018, 05:41 PM
#2
Banned
Join Date: Jan 2018
Location: Pennsylvania
Posts: 2,327
First, know this:
The thermostat can only determine when the cooling system is allowed to start cooling the engine.
It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the
hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the
water is to cold, it turns up the hot water. By regulating the flow through the cooling system it speeds
up and slows down the flow of coolant into and out of the engine block.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be
running at a temperature lower than it's design intended. The result is increased wear on the engine's
internals. It's essentially the same as if you assembled the engine with clearances tighter than designed
for because you didn't follow the directions or your tools were not calibrated properly.
If you are not tuned, race dragging, or running hotter heat range plugs, turbo or supercharged, then
you don't need a cooler temp thermostat. Around town and idling, you warm up faster than no
thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get
there however, especially on warm days, the only difference is you're trying to cool the car off as
it's trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator
fans kick on because radiators are poor cooling devices without air flow. In other words, sitting still,
the thermostat opening earlier doesn't matter much at all, because the fans aren't going to kick in
until the factory temp threshold is reached.
Regardless, it would take literally a second or two before temps would be regulated by the cooling
system, not the thermostat anyway since under load the engine is going to run well above the
thermostat fully open mark anyway.
The thermostat can only determine when the cooling system is allowed to start cooling the engine.
It sets a floor, not a ceiling on engine temperatures. The thermostat basically behaves like the
hot and cold ***** in your shower, if the water is too hot, it turns the cold on a little more and if the
water is to cold, it turns up the hot water. By regulating the flow through the cooling system it speeds
up and slows down the flow of coolant into and out of the engine block.
The problem with a low temp thermostat then for regular driving is that there are times when the car will be
running at a temperature lower than it's design intended. The result is increased wear on the engine's
internals. It's essentially the same as if you assembled the engine with clearances tighter than designed
for because you didn't follow the directions or your tools were not calibrated properly.
If you are not tuned, race dragging, or running hotter heat range plugs, turbo or supercharged, then
you don't need a cooler temp thermostat. Around town and idling, you warm up faster than no
thermostat at all, but you will take a while to warm up from 160 to 180 for example. You will get
there however, especially on warm days, the only difference is you're trying to cool the car off as
it's trying to warm up. As a mater of fact, if you sit there at idle, the temp will go up until the radiator
fans kick on because radiators are poor cooling devices without air flow. In other words, sitting still,
the thermostat opening earlier doesn't matter much at all, because the fans aren't going to kick in
until the factory temp threshold is reached.
Regardless, it would take literally a second or two before temps would be regulated by the cooling
system, not the thermostat anyway since under load the engine is going to run well above the
thermostat fully open mark anyway.
08-06-2018, 06:37 PM
#3
2nd Gear Member
Thread Starter
Join Date: Mar 2015
Location: Oregon
Posts: 188
Thanks for all that...I appreciate the overview.
I’m clear on how a thermostat functions and what it does.
I’m hoping to get some anecdotal opinions/experience regarding what thermostat temp rating might work best in my GT, which is charged but uses stock plugs, and has the additional cooling system capacity of the Vortech Ice Box. Any additional thoughts, anyone?
I’m clear on how a thermostat functions and what it does.
I’m hoping to get some anecdotal opinions/experience regarding what thermostat temp rating might work best in my GT, which is charged but uses stock plugs, and has the additional cooling system capacity of the Vortech Ice Box. Any additional thoughts, anyone?
08-08-2018, 07:11 PM
#5
3rd Gear Member
Join Date: Aug 2015
Location: SE Michigan
Posts: 939
I don't know enough about forced induction to comment on your specific setup. My knee-jerk reaction is to say just stick with the OE temp, but that's mainly based on seeing way too many owners trying to cover up cooling system problems by using the wrong t-stat.
But FWIW, I am seeing 195° listed as the stock thermostat temp for supercharged '03-'04 Cobras, the same temp as the rest of us. So I don't think you need to go any lower than that.
But FWIW, I am seeing 195° listed as the stock thermostat temp for supercharged '03-'04 Cobras, the same temp as the rest of us. So I don't think you need to go any lower than that.
08-08-2018, 11:38 PM
#6
2nd Gear Member
Thread Starter
Join Date: Mar 2015
Location: Oregon
Posts: 188
Thanks for the input. The rest of the motor is stock mechanically speaking. No cams, porting, stroking, boring...it’s all intake and exhaust breathing and forced induction. And the boost isn’t wild. I think the Vortech systems are designed for reliable operation balanced with good performance gains. I suppose the other factor that might effect how hot it runs (and how important it is for the t-stat to open and let the coolant out to the radiator) is the ignition timing curve which is a mystery at this point. The car came with the SHS MAFterburner when my wife bought it used before we started dating. Because the car has an incorrect intake manifold and had other problems that weren’t corrected, the tune was never right. I can tell you right now it runs rich by the smell. Once I get the manifold replaced and put new coils and plugs on (it’s had years of the heater hose port on the intake manifold pissing down two of the spark plug wells...problem misdiagnosed and unaddressed and now misfires so I’m just shotgunning all the coils and plugs...), then it will be time to load the MAFterburner software on an old Windows XP laptop, hook up the serial cable and head to the tuner’s and see what we’ve got. But the ignition curve could effect temp, yes? As it stands whatever is in there for the t-stat takes a long time to warm up. I think it’s too low temp. I think it’s 180 degrees. So I think I’ll test it on the stove and also pick up a 195 degree t-stat.
Thread
Thread Starter
Forum
Replies
Last Post