Who makes the best thermostat?
What are the pros/cons of using a 160* instead of a 180*?

Thanks

 

You're going to get a lot of opinions.

I have a Milodon 16401 high-flow 180 degree thermostat in my car. I also used the GM 10108470 aluminum waterneck ($5-) and a Fel-Pro 2022 gasket (no RTV required!). I have a small hole (1/8" I think) drilled in the thermostat to make sure there is always some flow, and to make sure I don't have trapped air.

I don't recall the pros and cons, just that this combination worked for both of my L48s. Stock is 195, 160 seems low and possibly unachievable, so the consensus on whatever threads I read at the time was 180.

 

Hi Jim, I like Bikespace's advice.

I'm sure you know this, but since you didn't say the reason(s) for your question, I'll say it anyway........ Are you having cooling issues, or just trying to make certain you don't get too hot on the warmest summer days? A thermostat is only one piece of the equation, and IMO a 160 is too cold and I agree with Bikespace that it won't be achievable. IF you have everything right, a 180 high flow will be a good piece of the puzzle.

How long has it been since coolant was changed? How old are the hoses, belts, and cap? How long since the radiator has been cleaned and pressure tested? Is the water pump good ( even though it might not be leaking/weeping, if coolant has been left too long at any point in the life of an older water pump, the impellers can corrode and lose some effectiveness. You can check them by pulling the back off the water pump - gaskets for the back can be had at any auto parts store)? Does your car have the right fan and is the shroud and all seals in place (if you have any parts of the shroud and/or seals missing, air will find ways around the radiator and you'll likely have heating problems). If your car has an overflow tank, is it set up and operating properly?

For the most part, I believe that if we restore our cooling systems back to the way the factory set them up, we'll be in good shape. There are certainly exceptions such as some of the high hp set ups - which may benefit from an aftermarket radiator like a DeWitts. I took the time (and $) to address all the questions above (and installed a DeWitts) and our '68 (427/435) runs as cool as could be, and I don't have to worry about it because I've gone thru/checked/replaced all components. I probably just cursed myself............

The short answer to your excellent question from MPOV: a high flow 180.

 

I don't know if it’s the best, but I like and use the Robertshaw Hi-Flow 195* thermostat. The one that can be used with any water pump. My car is a stock '79 L82 with a DeWitts aluminum radiator, and I've had no cooling problems at all.

Once you start your engine, the 180F stat will be shut and so will not permit radiator coolant to circulate through your engine until the engine temp rises to about 180F. Then it will open (to varying degrees, if necessary) to modulate your minimum engine water temp.

The thermostat really has no effect on your max temp reached. Your max engine temp is modulated by your radiator, outside air temp, vehicle speed, RPM, driving habits, running A/C, the important items mentioned above by Hopper12, etc.

For a classic Chevy engine, the question really should be between a 180F and a 195F, in my view. I like the 195F because I want that engine up near 200F as soon as possible, and it's recommend by my owner's manual. But I don't see a problem with a 180F in most applications.

The drawback related to a 160F is it will delay the warming up of your engine, without an upside. This will increase wear every time you start your engine, especially in cold weather.

 

A lot of these car's battle with keeping cool enough. Once the engine has been modified to produce more power. More power = more heat. I run a 160 high flow thermostat and a high flow waterpump. I also live in Australia. Cold is never a problem. It's much easier to keep the engine cool than it is to bring it back down once it's to hot. So yes I believe there is a advantage to running a 160 thermostat. And for the record, im running around 190 almost all the time. Warm up's are quick. My fans control the heat a lot more than the thermostat.
So, where you live and the mods done on your engine do come into play.
Just thought I'd comment after the last post. Yes, it maybe just my opinion, but I truly believe that it's easier to keep the heat down in the first place than to bring it down once it's to hot.

 

stant 180. unless you think you are smarter then GM engineers who spent countless hours and dollars figuring out what is best for everyday driving