Ideal Thermostat Temp???
Thread Starter
"Rodstoration &am p;quot; In Progres
Joined: Jun 2004
Posts: 1,397
Likes: 1
From: Frisco TX
Ideal Thermostat Temp???
Which Thermostat do you recommend for my engine... (168 or 195 degree)???
Original L48 now 383 stroker
SRP forged flatops w/ molly rings
Forged H-Beam Rods
SCAT crank
Edelbrock RPM Heads (64cc) ported and polished
Edelbrock RPM AirGap Intake
Demon 750
Hooker Comp Headers
Dewit upgraded Radiator
Dual 11" SPAL fans
Thanks in advance...
Original L48 now 383 stroker
SRP forged flatops w/ molly rings
Forged H-Beam Rods
SCAT crank
Edelbrock RPM Heads (64cc) ported and polished
Edelbrock RPM AirGap Intake
Demon 750
Hooker Comp Headers
Dewit upgraded Radiator
Dual 11" SPAL fans
Thanks in advance...
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
For a street driven performance car I prefer 180, gets the eng up to an operating temp that allows for good oil flow, cooks off eng oil contaminants and keeps fuel atomized but not so hot to kill performance.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
I run a 195 degree thermostat on my '69 L46; it stays right around 200-205 and no signs of detonation.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
if you have all the emissions equipment removed than run a 180º t-stat. If you left the emission equipment on than stick with the 195º t-stat.
Basically, 180º is typically t-stat you want to run, but if emission equipment is still there it requires a hotter operating temp to have the emission equipment work properly.
Basically, 180º is typically t-stat you want to run, but if emission equipment is still there it requires a hotter operating temp to have the emission equipment work properly.
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
I am running a 180 in my vette. When rolling I stay on 180 when stuck in traffic the car will ease up to around 200 and the fan will cool it back down to 185 or so.
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
I have the same heads with no cross over, and with a 160 thermostat, it took along time for the maifold to warm up and stop the hesitation. A 180 works much better. Being in the South, you may not have the same problem.
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
180. Somewhere in the archives is a great post (a few years back) talking about the stat rating. It's got to balance performance with lubrication efficiency. The two graphs peaked either side of 180, making 180 the best choice for street driving with engine longevity. If you run it too cool then contaminants also build up, as stated. Manufacturers apparently use a 195 stat to increase lube efficiency (got to keep warantee claims in mind) & emissions down in cars used for all types of driving eg, short, start-stop trips as well as highway driving. Better power at lower temps, better lube at higher temps, so it's a compromise. That's all I remember of it (besides, the computer in mine throws a wobbler if I use a 160 stat 
).
).
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Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
160 is too cold.
A hot engine runs better than a cold engine up to a certain temp.
Other than hiding oil leaks, theres a reason for painting an engine black.
I use 185 and thats what my cars gets up to.
The temp numbers is what your temp should get up to and not any higher.
A hot engine runs better than a cold engine up to a certain temp.
Other than hiding oil leaks, theres a reason for painting an engine black.
I use 185 and thats what my cars gets up to.
The temp numbers is what your temp should get up to and not any higher.
Burning Brakes
Joined: Jul 2006
Posts: 1,047
Likes: 12
From: SoCal
This has been discussed before, and IIRC in one of the previous threads a poster mentioned that GM recommends 180 degrees and anything cooler than that can cause excessive cylinder wear. But don't quote me!
I run a 180 degree high-flow thermostat in my '73.
I run a 180 degree high-flow thermostat in my '73.
Last edited by VCuomo; Jul 6, 2007 at 04:10 PM.
Burning Brakes
Joined: Jul 2006
Posts: 1,047
Likes: 12
From: SoCal
If you're assuming a 100% efficient cooling system then you're correct - but that's not how it is in a real car.
Or am I misunderstanding what you're saying?
Last edited by VCuomo; Jul 6, 2007 at 04:09 PM.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
The number on a thermostat is how hot the water should get.
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
The number on a thermostat is how hot the water should get.
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
Last edited by Eddie 70; Jul 6, 2007 at 06:18 PM.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
Ok lets look at this.
Your car is cold, you start it and while the engine is running, the stat is closed until the water temp reaches the number on the stat. Otherwise the water is not moving in your engine or radiator until the stat opens.
If its 185 that means when the water gets 185 degrees it triggers the stat to open which lets water go thru your top radiator hose and into the radiator, this pushes cold water down and thru the bottom hose into the water pump and flows into the block. This water being cooler reaches the thermostat and makes it close until your engine heats it up to trigger the stat to open up and cycle again.
So only water that is 185 degrees or hotter will trigger the thermostat to open, the the engine should cool down in temp not up.
So in a perfect cooling set up your temp should never get hotter than the number on the thermostat, colder yes, hotter no.
Mine runs 180, I have a new 4-core,fan shroud,18 inch flex fan and aluminum water pump and front factory air dam(spoiler).
In a nut shell a car with a 185 thermostat should never get hotter than 185 degrees.
Unless you are in Alaska and its 40 below it probably won't run much cooler than 185 either.
Your car is cold, you start it and while the engine is running, the stat is closed until the water temp reaches the number on the stat. Otherwise the water is not moving in your engine or radiator until the stat opens.
If its 185 that means when the water gets 185 degrees it triggers the stat to open which lets water go thru your top radiator hose and into the radiator, this pushes cold water down and thru the bottom hose into the water pump and flows into the block. This water being cooler reaches the thermostat and makes it close until your engine heats it up to trigger the stat to open up and cycle again.
So only water that is 185 degrees or hotter will trigger the thermostat to open, the the engine should cool down in temp not up.
So in a perfect cooling set up your temp should never get hotter than the number on the thermostat, colder yes, hotter no.
Mine runs 180, I have a new 4-core,fan shroud,18 inch flex fan and aluminum water pump and front factory air dam(spoiler).
In a nut shell a car with a 185 thermostat should never get hotter than 185 degrees.
Unless you are in Alaska and its 40 below it probably won't run much cooler than 185 either.
Burning Brakes
Joined: Jul 2006
Posts: 1,047
Likes: 12
From: SoCal
The number on a thermostat is how hot the water should get.
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
If you have a 180 then thats when the stat opens, if it gets hotter its not the stast fault.
Room temp is your minimum.
People beleive if you have a 180 stat that is the minimum temp and then its up from there but its not!
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
My theory is that if you have a 195* stat, the engine temp should run at 195 with approximately +/- 5* (190-200) as you roll along, as the stat opens and closes, in any driving condition...at least, mine does that....also, winter driving should also cause consideration as to stat temp....up here in the Great White North...there are days you REALLY want a lot of heat in the cockpit 
Just my 2 cents....
Just my 2 cents....
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Ok lets look at this.
Your car is cold, you start it and while the engine is running, the stat is closed until the water temp reaches the number on the stat. Otherwise the water is not moving in your engine or radiator until the stat opens.
If its 185 that means when the water gets 185 degrees it triggers the stat to open which lets water go thru your top radiator hose and into the radiator, this pushes cold water down and thru the bottom hose into the water pump and flows into the block. This water being cooler reaches the thermostat and makes it close until your engine heats it up to trigger the stat to open up and cycle again.
So only water that is 185 degrees or hotter will trigger the thermostat to open, the the engine should cool down in temp not up.
So in a perfect cooling set up your temp should never get hotter than the number on the thermostat, colder yes, hotter no.
Mine runs 180, I have a new 4-core,fan shroud,18 inch flex fan and aluminum water pump and front factory air dam(spoiler).
In a nut shell a car with a 185 thermostat should never get hotter than 185 degrees.
Unless you are in Alaska and its 40 below it probably won't run much cooler than 185 either.
Your car is cold, you start it and while the engine is running, the stat is closed until the water temp reaches the number on the stat. Otherwise the water is not moving in your engine or radiator until the stat opens.
If its 185 that means when the water gets 185 degrees it triggers the stat to open which lets water go thru your top radiator hose and into the radiator, this pushes cold water down and thru the bottom hose into the water pump and flows into the block. This water being cooler reaches the thermostat and makes it close until your engine heats it up to trigger the stat to open up and cycle again.
So only water that is 185 degrees or hotter will trigger the thermostat to open, the the engine should cool down in temp not up.
So in a perfect cooling set up your temp should never get hotter than the number on the thermostat, colder yes, hotter no.
Mine runs 180, I have a new 4-core,fan shroud,18 inch flex fan and aluminum water pump and front factory air dam(spoiler).
In a nut shell a car with a 185 thermostat should never get hotter than 185 degrees.
Unless you are in Alaska and its 40 below it probably won't run much cooler than 185 either.
Are you actually seeing temperature fluctuations on the temperature gauge? I have a '91 Silverado that does this until it warms up but after that the temperature is steady with a constant flow through the entire system.
If your engine temperature is really fluctuating up and down like that you're doing your engine more harm than good.
BigBlockk
Later.....