How to pick a thermostat

[Squareforceone]

I'm swapping from a 305 sbc in my 84 to a mildly built 350 and need to replace the thermostat just wondering which to choose i know theres different temperature ones

[mud.man.rj]

Anything around your year and back uses a 180 after 88 and up usually use a 195 degree.

[Tx Firefighter]

Where you live, I'd run a 195. The heater will work better.

[cableguy0]

If your cooling system is working properly a 195 thermostat is the way to go. The hotter engine temp will keep the moisture out and allow a more complete burn in the combustion chamber. Running the engine cold does nothing good for it.

[Gumby]

Operating temperature vs power and longevity!
http://www.carnut.com/ramblin/_cool3.html

[mud.man.rj]

I would install what Gm calls for which is a 180, not a 195. I run a 180 all year round and it gets to -20 to -35C here in the winter, ya coold. Your choice but sure Gm knows what they are talking about haha. A 195 will work but in summer on a hot day may make it runa bit to warm and cause it to ping.

[crazy longhorn]

Originally Posted by Gumby

Operating temperature vs power and longevity!
http://www.carnut.com/ramblin/_cool3.html

Good info Still (old school), a carbureted engine should run 180-185 on coolant temps, to keep the carb/fuel cool enough? Not here to argue, but just so you know....I can run a 160 stat, & maybe trim a dime off the temp? With the lower temp stat, it will take more warm up time, but the system will run where it wants, after warm up! It all depends on the radiator/shroud & fans (S) running? Longhorn

[Gumby]

I run a 180 with a tiny burb hole in it.........

[storm9c1]

Originally Posted by Gumby

I run a 180 with a tiny burb hole in it.........

+1.

180 degree is just right, add the 1/16" - 1/8" hole to prevent trapped air since a thermostat can't read air very well. It may also help the thermostat open sooner on a hot day since it allows cooler coolant to be displaced with warmer coolant a little faster.

Not trying to cause debate. I've just used 160 and 195 stats on different vehicles, never liked them much. There was usually some root cause that needed fixed that a different temp thermostat really didn't fix. For example, an overheating vehicle doesn't need a 160 degree stat, it needs the cooling system checked. And bad heat in the winter usually means a clogged heater core or stuck fan clutch, so a 195 isn't the right solution there either. But that's just my opinion... and we all know what opinions are like........

[Tx Firefighter]

Speaking of the burp hole.

Here is a trick we used to do when I was hustling flat rate in high paced shops.

Buy a 99 cent bottle of aspirin to keep in your tool box. When you install a thermostat, push it open with your fingers and wedge two aspirins in the gap, across from each other. Now install thermostat and fill with coolant. The aspirins will hold thermostat open and it will bleed air allowing you to fill the system completely. Then as the water rises up past the thermostat, it will dissolve the aspirins and allow thermostat to work normally from then on.

I agree about the 160 degree deal. If it overheats with a 180 or 195, its a cooling system problem not to be fixed by a lower temp stat. When the manufacturers went to 195 degree units back in the 80s I got on board with the idea. Its healthy for the engine to run warm. The oil stays cleaner. Plus that extra 15 degrees of heat at the vents is nice.

[storm9c1]

Originally Posted by Tx Firefighter

Speaking of the burp hole.

Here is a trick we used to do when I was hustling flat rate in high paced shops.

Buy a 99 cent bottle of aspirin to keep in your tool box. When you install a thermostat, push it open with your fingers and wedge two aspirins in the gap, across from each other. Now install thermostat and fill with coolant. The aspirins will hold thermostat open and it will bleed air allowing you to fill the system completely. Then as the water rises up past the thermostat, it will dissolve the aspirins and allow thermostat to work normally from then on.

I guess the car wouldn't have any headaches for a while after that, eh?

I've heard of this too -- anything from candy to vitamin pills to small pieces of toilet paper folded up in a wad. No wonder I work on my own cars these days. I'd never put any of those things in an engine. But getting paid under time pressure, I guess you do what you have to do.

When the manufacturers went to 195 degree units back in the 80s I got on board with the idea. Its healthy for the engine to run warm. The oil stays cleaner. Plus that extra 15 degrees of heat at the vents is nice.

AFAIK, they switched to 195 primarily for emissions. In harmony with a cat converter, EGR, and an AIR pump in some applications, the higher temp actually helped increase efficiency of the combustion and lowers emissions. But all components need to be in place and operating properly to do so. For example, while a higher engine temp alone will help efficiency, it will increase NOx without the other provisions.

I also agree that a higher temp will help get rid of moisture and some other contaminants in the engine, and that will help oil stay cleaner, but there is a law of diminishing returns here since oil also breaks down with too much heat.

Good discussion!

[GASoline71]

Originally Posted by Gumby

I run a 180 with a tiny burb hole in it.........

Same here... 180's in anything before the TBI... then I go with 195's on the later model stuff.

Gary

[Redcap]

I run 195s in everything.

[GASoline71]

Your climate down there is dang near the same as mine up here. Do you run those in the hot rods? Or just the stockers. If I could get any kind of benefit out of it... I'd switch the 'stat in my hot rod from a 180 to a 195.

Gary

[Redcap]

Originally Posted by GASoline71

Your climate down there is dang near the same as mine up here. Do you run those in the hot rods? Or just the stockers. If I could get any kind of benefit out of it... I'd switch the 'stat in my hot rod from a 180 to a 195.

Gary

Yup. I don't see any benefit to running a 180, but I'm also pretty big on making sure my cooling systems are up to snuff.

[hardcore4life]

I would run what the factory recommends. Engineers spent years designing this stuff for a reason.

[Redcap]

Originally Posted by hardcore4life

I would run what the factory recommends. Engineers spent years designing this stuff for a reason.

That statement is amusing to no end.

[GASoline71]

Originally Posted by Redcap

Yup. I don't see any benefit to running a 180, but I'm also pretty big on making sure my cooling systems are up to snuff.

Me too... my cooling systems aren't just and afterthought after a rebuild trying to use the clogged up 40 year old radiator and kinked hoses.

Gary

[72bowtiestepper]

Originally Posted by Tx Firefighter

Speaking of the burp hole.

Here is a trick we used to do when I was hustling flat rate in high paced shops.

Buy a 99 cent bottle of aspirin to keep in your tool box. When you install a thermostat, push it open with your fingers and wedge two aspirins in the gap, across from each other. Now install thermostat and fill with coolant. The aspirins will hold thermostat open and it will bleed air allowing you to fill the system completely. Then as the water rises up past the thermostat, it will dissolve the aspirins and allow thermostat to work normally from then on.

I agree about the 160 degree deal. If it overheats with a 180 or 195, its a cooling system problem not to be fixed by a lower temp stat. When the manufacturers went to 195 degree units back in the 80s I got on board with the idea. Its healthy for the engine to run warm. The oil stays cleaner. Plus that extra 15 degrees of heat at the vents is nice.

I like that idea fireman...Thanks !

[520CheyenneK10]

Well I just did the flush, refill, coolant hoses and Thermostat change today at the house and I for one have always run 180 degree Thermostats in all my SB 350's. My take is that here in southern AZ. where temps in the summer get really hot and in winter may never reach freezing I can get away with the 180 and not use the 195. I did remove a 195 and put a 180 in with Peak Long Life 50/50. When temps are as they run here I think my engine gets plenty of ambient heat as well as internal. So anyways that's my thought on this subject.