stock thermostat temp for 67 inline six? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cell · 07-24-2006, 03:37 PM

I put a 195 degree thermostat in my freshly rebuilt 292, and installed a heavy duty radiator (28.?" wide, 4 core). When I run it, the original temp guage goes right up to where the red zone starts (not quite all the way pegged), but doesnt go any higher (even after half an hour of running in the driveway and several hours of driving).

Are the stock guages on these trucks meant to be used with a cooler thermostat, like 165 degree maybe?

I saw a thread about pegging the guage because of a short, but that isn't the case here. The needle starts in the cold and takes a few minutes to point to the red.

shelby987 · 07-29-2006, 09:41 PM

I can't directly answer your question, my truck didn't originally come with a factory temp gauge, but I have since installed aftermarket gauges, and my 250 is rock solid at 220, whether it be cruising on the highway, driving around town, towing, idling, etc, (yes, the gauge does start below the 130 deg. minimum) so far the only change I have made to the cooling system is half a bottle of water wetter, an overflow bottle, and a thermo clutchable fan.

cell · 07-29-2006, 11:24 PM

yeah, I noticed that my truck didn't appear to come with an overflow reservoir. I picked up an aftermarket kit from the local auto parts store, and it appears to be working fine.

ThatOneBlue67 · 07-30-2006, 11:07 AM

My 250 wanted to run 210 w/ a 180 thermostat. According to the parts dealers, GM actually recommends free-flow. I would not. Neither that or the 195. These engines, for some reason, want to run hot when they get older. I would recommend FIRST getting a more precise temp gauge. IMHO, I beleve that the temperatore on these should be in between 175 and 195. Getting into the 200's is just way too hot to keep it that way.

Now I have a 160 thermostat and it keeps my temperature at 190 on hot days and 160 on cold days.

You should try experimenting with the 160, but be careful! While this works fine for my application (stock radiator & 250) it could have different affects with a newer, more efficeint radiator (i.e. the water not getting enough radiator time to cool down).

So, maybe try a 180 first and, if not good enough, try the 160.

cell · 07-31-2006, 02:17 PM

interesting ThatOneBlue67. I picked up a 180 and I'll give that a shot for a while. I'll let y'all know how it goes.

67ChevyRedneck · 07-31-2006, 02:24 PM

What kind of fan do you have? Do you have a fan shroud? My 250 six popper ran hot until I installed a full fan shroud.

bryanw1968 · 07-31-2006, 04:13 PM

There are many variables that affect temp. As mentioned above, fan shrowd, thermastat selection, radiator size and overflow are very important. I had an autozone 180 in my truck and it pretty much ran between 189 and 191 all the time unless sitting. I recently replaced it with a performance thermastat(mr. gasket I think) and it made a HUGE difference. It stays exactly on 180 and runs much better. 180 is plenty hot for the oil but once you start creeping up to 200 I believe that's just too hot for these older motors.

07-24-2006, 03:37 PM	#1
cell Active Member Join Date: Nov 2005 Location: Austin Posts: 217	stock thermostat temp for 67 inline six? I put a 195 degree thermostat in my freshly rebuilt 292, and installed a heavy duty radiator (28.?" wide, 4 core). When I run it, the original temp guage goes right up to where the red zone starts (not quite all the way pegged), but doesnt go any higher (even after half an hour of running in the driveway and several hours of driving). Are the stock guages on these trucks meant to be used with a cooler thermostat, like 165 degree maybe? I saw a thread about pegging the guage because of a short, but that isn't the case here. The needle starts in the cold and takes a few minutes to point to the red. Last edited by cell; 07-24-2006 at 03:39 PM.

07-29-2006, 09:41 PM	#2
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: stock thermostat temp for 67 inline six? I can't directly answer your question, my truck didn't originally come with a factory temp gauge, but I have since installed aftermarket gauges, and my 250 is rock solid at 220, whether it be cruising on the highway, driving around town, towing, idling, etc, (yes, the gauge does start below the 130 deg. minimum) so far the only change I have made to the cooling system is half a bottle of water wetter, an overflow bottle, and a thermo clutchable fan. __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!

07-29-2006, 11:24 PM	#3
cell Active Member Join Date: Nov 2005 Location: Austin Posts: 217	Re: stock thermostat temp for 67 inline six? yeah, I noticed that my truck didn't appear to come with an overflow reservoir. I picked up an aftermarket kit from the local auto parts store, and it appears to be working fine.

07-30-2006, 11:07 AM	#4
ThatOneBlue67 I survived Dead Man's Curve. Join Date: Apr 2006 Location: The Nine-Five-687 Posts: 389	Re: stock thermostat temp for 67 inline six? My 250 wanted to run 210 w/ a 180 thermostat. According to the parts dealers, GM actually recommends free-flow. I would not. Neither that or the 195. These engines, for some reason, want to run hot when they get older. I would recommend FIRST getting a more precise temp gauge. IMHO, I beleve that the temperatore on these should be in between 175 and 195. Getting into the 200's is just way too hot to keep it that way. Now I have a 160 thermostat and it keeps my temperature at 190 on hot days and 160 on cold days. You should try experimenting with the 160, but be careful! While this works fine for my application (stock radiator & 250) it could have different affects with a newer, more efficeint radiator (i.e. the water not getting enough radiator time to cool down). So, maybe try a 180 first and, if not good enough, try the 160. __________________ "The people should not be afraid of their government. The government should be afraid of it's people." "The Hurricane" 1967 Chevrolet C10 350 Eight Cylinder, 700R4 BowtieOverdrive *Cherry Bomb...* Disturbing the Peace Since 1968.

07-31-2006, 02:17 PM	#5
cell Active Member Join Date: Nov 2005 Location: Austin Posts: 217	Re: stock thermostat temp for 67 inline six? interesting ThatOneBlue67. I picked up a 180 and I'll give that a shot for a while. I'll let y'all know how it goes.

07-31-2006, 02:24 PM	#6
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: stock thermostat temp for 67 inline six? What kind of fan do you have? Do you have a fan shroud? My 250 six popper ran hot until I installed a full fan shroud. __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

07-31-2006, 04:13 PM	#7
bryanw1968 Senior Member Join Date: Jul 2006 Location: Leander, Texas Posts: 850	Re: stock thermostat temp for 67 inline six? There are many variables that affect temp. As mentioned above, fan shrowd, thermastat selection, radiator size and overflow are very important. I had an autozone 180 in my truck and it pretty much ran between 189 and 191 all the time unless sitting. I recently replaced it with a performance thermastat(mr. gasket I think) and it made a HUGE difference. It stays exactly on 180 and runs much better. 180 is plenty hot for the oil but once you start creeping up to 200 I believe that's just too hot for these older motors.



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