Ryan77

I have both a 180* thermostat and a 160*, the 180 is on the car now. I'm not sure what the car was running at as the temp gauge is broken. I'll be flushing the cooling system, and adding a bottle of the "Purple Ice" coolant additive. Which thermostat should I use?


[Modified by Ryan77, 3:26 PM 1/25/2003]

flynhi

stay with 180

CF6873

:iagree:

LiveandLetDrive

Contrary to popular belief, thermostats make little to no difference in operating temperature. They are for warm up. Assuming you normal operating temperature is over 180, go with the 180, the 160 is just going to make it take longer to get up to temp.

-Chris

Metal Wulf

when I had a 180* my gauge always read 210-215, I switched it to a 160* and now my gauge reads 195-200.

corvettemaster

I have both a 160 and 180 thermostat also. I had a 160 in it, but do to the cold weather, it took it a while to heat up (like mentioned above), so I put a 180 in it. Probably switch back to 160 when spring rolls around.

Ryan77

That's what I thought, the thermostat opens at 160* or 180*, but that's just when it starts to flow coolant, the motor will still reach it's operating temp, but just take longer to get there. Correct? The car is driven from May 1 to October 31, so it doesn't see too much cold weather, that's why I was thinking about going with the 160*, but i'm still kind of leaning toward the 180* at the moment.


[Modified by Ryan77, 4:58 PM 1/25/2003]

Ryan77

195*-200* is where I would like the car to operate at.

Ganey

In general for a SB perf., 180. 160 can run too cold in winter, depends on the cooling system.
Running lower than stock on a stock car w/ some emissions sys. connected may not let them turn off like EFE in the rt. ex. manifold.
Sto*k not rec.!
http://performanceunlimited.com/illu...ermostats.html

SanDiegoPaul

195*-200* is where I would like the car to operate at.


Agreed! :iagree:

With the high-efficiency core I put in the radiator when I installed the 388, it runs only about 175 with a 180 t-stat. I intend to replace it with a 195 soon.

GrandSportC3

I run a 160 degree thermostat.. but the normal operating temp is between 180 and 195 degrees...

:cheers:

Olivier

jerryp58

"Contrary to popular belief, thermostats make little to no difference in operating temperature. They are for warm up"

While I've always agreed with this statement, there is something about thermostats that I don't believe I've ever read in the "thermostat threads" here on the forum. The specification in my Chevrolet 1977 Corvette Specifications booklet (FREE from Chevrolet; call 800-222-1020) says that the thermostat should begin to open at 192-198 degrees and is fully opened at 227 degrees .

My personal experience is that my car runs at about 205 degrees with either 180 or 195 thermostat. So, I guess that if my 195 thermostat was the same design as the original, then it was never fully opened at 205. I don't know the range on my 180 thermostat, but I would guess that it would be closer to fully opened at 205. I know I have read here that the restricted flow the thermostat provides is part of the heating/cooling design for the block & heads (not to heat up or cool down too quickly), so I don't know if I'm harming my engine with a 180 or not.

I'm not sure if any of this is helpful; I know it's made my head hurt :skep:

Schmucker

My thermostat didn't work. Died in the open position. Car took forever to warm up, and it was still under 200 degress. Probably about 180-190. Now I stuck a 180 in there and still only gets to 180-190. I need something that makes some power and therefore some heat! Should be fine with the motor I build this winter... 160 is just too low I think. 195 seems a bit too high too. Although my dad said he read about a test on a big block. They dynoed it with more power at 120 degrees than at normal operating temp (200+ I'd imagine). So who knows.

Ganey

Jerry

Evidently you missed them, have posted several times:
The thermostat rating is the opening temp. & it is not fully open until about 25 degrees later. The purpose of the thermostat is to get the engine up to operating temp. ASAP. This is well known. It is barely believable that bubba thinks it is for the heater.

Ryan77

There is no emmisions equiptment connected on my vette :D , and I only drive the car from May 1 to October 31, so winter driving is no a factor, pretty much warm weather driving. I'll check out that link too :cheers:

Taijutsu

As usual good comments all around. Let me add a quote for Smokey Yunick. Use a 160 for best power and a 180 for mileage and emmissions. Since then I have seen a tech paper on lubrication that states an engine that runs at 160 is too cold and will have 3x the wear of an engine @ 180. I run a 180 w/dual spals and rebuilt 4 core on my 74. This summer it got up to 112 and I had zero problems w/AC running! Just my .02

Ganey

Running an engine at 180* will drop the overall HP by 2-3%. For max power the coolant temp should be at least 200*...
Actually, a racing engine like the SBC will produce more HP as the operating temp. is increased up to a maximum of about 220*. This can be confirmed w/ dyno testing, but I would not unconditionally rec. that any engine be raced at 220*. This leaves very little leeway for variations in the operating environment... Nonetheless for maximum power output, the coolant temp in a racing engine should be in the 200-210 range, measured at the point where the coolant is returned to the radiator.
Smokey Yunick

p.121

Ryan77

I think I'll stick with the 180* thermostat then :cheers:

Paul L

I'll throw in my two cents based on experience. As Ganey noted, the thermal vaccum switches (TVS) for EFE and EGR will not operate properly at 160. And at 180 they are marginal. I ran that experiment last summer. The only stat that worked for me is shown below. And before you, and others, get into the cool argument, remember that GM designed the engines to work at certain temps. And in the late 1970s that was 200+. And they do work well at those temps, believe me. To maintain those temps requires a t-stat that will retain the engine at a constant state of about 195F. Keep in mind that that is when the t-stat opens; above that it is free-flow. If a car is running high heats, do not blame the t-stat, the blame lies elsewhere.

It constantly amazes me that people think that a 160 t-stat will assure that running temperature under high-heat ambient conditions. No. It simply delays warm-up as the stat opens when the coolant is relatively cold. A 160 t-stat has absolutely no influence at all on a fully warmed-up engine: it has been open many minutes before warm-up is achieved and only contributed marginally to that procedure. And after that it is fully open, never to close. Go to 195 and you will be happy with the results.