93 Corvette thermostat
Thread Starter
Heel & Toe
Joined: Mar 2015
Posts: 18
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93 Corvette thermostat
I'm new to this site, I picked up a 93 corvette this winter and the previous owner removed the thermostat. On the highway right now my temp is only running around 140, is this going to be bad if I run it this way long term or should I get at least a 160 thermostat? I'm thinking the only bad part is in traffic and in town driving it will get up to 200 then quickly cool down again to 140, this drastic change in temps may crack heads I'm thinking or am I wrong. Anyone ran without a thermostat long term on here?
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I'm new to this site, I picked up a 93 corvette this winter and the previous owner removed the thermostat. On the highway right now my temp is only running around 140, is this going to be bad if I run it this way long term or should I get at least a 160 thermostat? I'm thinking the only bad part is in traffic and in town driving it will get up to 200 then quickly cool down again to 140, this drastic change in temps may crack heads I'm thinking or am I wrong. Anyone ran without a thermostat long term on here?
I have run engines for long periods (right on by 200,000 miles) at low temps (both w/o a stat and w/low temp stats -my boat for example which typically runs 150-160). I've never observed any detriment in doing this, but you will get a plethora of responses claiming that "YOU'LL RUIN YOUR MOTOR!" from the alarmists.
Although I am sure that you won't ruin your motor, unless you have a very specific reason to run it that cool (drag racing for example), then for a driver's car, I'd get the temps where they belong. 180 stat is stock in an LT1.
Thread Starter
Heel & Toe
Joined: Mar 2015
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I'm wondering if there's an overheating issue myself and thats why the thermostat was pulled out. I haven't had a chance to check to make sure the fans are working yet or not. At what temp are they supposed to kick in?
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
That my be an accurate theory on why the stat has been removed. It is a very common REACTION, to lower the T-stat temp (or remove it) in an attempt to "fix" hot running. I would investigate, for sure.
Fans come on at ~230*F, and only below ~30 mph. Let it sit, idling for a bit (which watching your digital temp display) and see what happens.
SIDEBAR (and me making a point): Interesting that you're engine is not over heating w/the stat removed. If you believe common lore, w/the stat removed, your coolant is moving too fast and won't cool in the radiator.
Fans come on at ~230*F, and only below ~30 mph. Let it sit, idling for a bit (which watching your digital temp display) and see what happens.
SIDEBAR (and me making a point): Interesting that you're engine is not over heating w/the stat removed. If you believe common lore, w/the stat removed, your coolant is moving too fast and won't cool in the radiator.
Race Director
Joined: Sep 2001
Posts: 10,560
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From: Wellington, FL
St. Jude Donor '11 thru '25
I'd install the correct thermostat, probably 195 degrees, and go from there. Running without a thermostat creates longer warm up times and when the car doesn't reach full warm up, it can create condensation in the engine (oil) and exhaust system, not something you want. If you haven't changed the oil & filter yet, I do so. Good luck with the ride.
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Race Director
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I always wondered about that. I have never seen any tests. There is a thermodynamic equation that describes heat exchange between a radiator and the atmosphere but I never bothered to look it up. Too many unknowns to be practical for solving this problem.
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Team Owner
Joined: Aug 2004
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From: Park City Utah
"Water moving too fast" is left-over LORE, from the old days...or made up stuff from people's heads. Here are the facts, from Stewart Components, and here is where the lore came from:
A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.
Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.
Large coolant flow/volume not only keeps the radiator core as hot as possible (which = the greatest heat transfer), it also creates a lot of turbulence in the cooling system, which also improves heat transfer.
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Last edited by Tom400CFI; Mar 12, 2015 at 10:17 PM.