Which Thermostat for 78? 180 or 196

 

i run a 160. don't want it running as hot as some others. i drill a couple small holes in the flange to prevent air pockets

 

Temp of thermostat is ONLY for the initial warming-up. Most engines will run over the thermostat rating. A normal engine will never drop down to the thermostat rating while it is running.

Saying that it will run cooler with a 160 is a myth.

If your engine runs normally at 160 you are asking for problems.

A 180 or 195 will let the engine warm up quicker before letting the coolent run thru the engine.

 

never had a problem with a cooler thermostat. a cooler running car being a bad idea is unfounded and an old wives tale. and i was not saying the thermostat controlled the temperature the car runs. but it does affect it and yes my car does run 160 degrees

 

I'm going to agree with you on this one, too. I've read so many of these thermostat posts over the years and there are always the guys who say the thermostat doesn't control the engine temp. Well, if that's the case, then why does my car run at about 160 with the 160 thermostat? When I put in a 180, it runs much hotter. Actually gets up to about 200*. Many here have said it determines the rate at which the engine initially warms up. Actually, they all warm up at the same rate with a thermostat, but the engine with the 160 stat opens first and starts cooling the coolant first. That helps to determine the operating temp of that engine. If I run a cooler thermostat in my truck in the winter, I only get luke warm air out of the heater and my engine never fully warms up. When I change it over to a 180 or a 195, the heat pours out with absolutely no problem and the engine reaches full operating temp.
I've always run a 160* in my Vette and I only use it in really nice weather. I don't have A/C, but I like to see the temp gauge stay nice and cool. (around 160) It's never affected performance. In fact, when we used to run at the drags and the circle tracks on Sat. nights, everyone did whatever it took to keep things cool. Cool cans for fuel (dry ice) extra capacity radiators and we even ran a heater core with the fan on high in the street stock car until we got caught. Keeping the temps down helped performance. Imagine that!
Duane

 

OK guys, it's your car.
Then just don't run a thermostat and it should run even better.

 

I am always in awe of the chase of cooler engine temps.

 

I think 2 questions come up here.

- At what temps does fuel properly atomize and burn properly?
- At what temps in an engine do engine deposits and moisture build and not get properly burnt off?

Has someone ever run dynos at various engine temps to see where efficiency and power vs temps come in?

Personally, in a colder climate the 180 is perfect for a BB, the stock 195 is just too hot and a 160 seems to not make power.

 

My oh my when does it ever end. Lol...

 

Stock was 195.

 

GM designed their V8's for 180F operating temps. The EPA then demanded to lower emissions and a simple way to help that at idle was to run the engine hotter...thus, 195F stats.

180F is the optimum running temperature. GM said so...you can disagree, if you want. Running hotter temps reduces emissions...and fuel mileage, and reliability, and oil/engine life. Maybe not by a LOT, but all those things are somewhat worse. Running a cooler stat will allow the engine to be a tad more efficient at the expense of longer warm-up times (do you run your C3 in the winter and need quick warm-ups for heater "action"?) and some small reduction in engine life. Again, the losses here are minor, at best.

If your engine runs cooler and you feel better running a 160F stat, have at it...no real harm done. If you are 'green' and want to lower emissions, install a 195F stat. If the extra engine heat doesn't bother you, dandy.

There are viable reasons to run a stat anywhere from 160F to 195F, and that should be a personal choice of the vehicle's owner. Everyone else can argue about what stat someone should put in their car...but those arguments are just more talk.

 

actually 440 degrees is about where gasoline vaporizes and would be the ultimate for power and efficiency read about smokey yunick's hot vapor engine.

 

An engine is designed with specific piston and bearing clearances. These clearances are only correct at a predetermined temperature. Running hotter or cooler than this temperature increases or decreases these clearances.

 

True. That change is in the millionths of an inch per degree F [or C] change. 20*F change, either way, if of no real consequence.

 

It is with forged aluminum pistons.

 

the intangibles are age, water jacket clog%, radiator clog %, accuracy of the thermostat ( made in china right? ), fan blade clutch wear, antifreeze solution %, water pump efficiency, piston/bearing clearance at a specific temp, idleing in traffic or moving at freeway speeds, cap pressure rating, pulley size, belt slippage....

with a 180, my car would spit antifreeze when I shut it down after an extended drive, and the carb would percolate. I do have a shroud, but no radiator foam seals.

all that was solved with a 160.

it just depends on your situation. they are cheap enough so that you can experiment.

you might have to pop in a 195 so you can get past your emissions *****.

 

Actually, the operating temps in the combustion chamber will be nearly the same, regardless of what stat you run. As was mentioned earlier, the stat DOES NOT establish the operating temp of the engine...it merely establishes the LOWEST temperature at which the engine can operate. If the cooling system doesn't have the capacity to keep it at the stat temp, the engine temp will rise until it reaches equilibrium with the cooling system's capacity. Most stock Chevy V8 engines/cooling systems are designed to stabilize at about 170*F. You can pull the stat out of the engine and it would still stabilize at 170*F. It would just take longer to get there.

 

My vote is a 180 degree 'stat. Most engines run a bit hotter than that, anyway. IMHO, a 160 will only increase the cold running time. If you feel the need to drill a hole in your 'stat to vent air bubbles, don't. The manufacturers put one in at the factory, and it is tiny. Just enough for small amounts of air. Once the system has run through a few heat/cool cycles, and if you have an overflow system that is working, all the air is gone, anyway.
I once had a C2500HD pickup that some &%$@ had installed a thermostat with two 1/8" holes in it. It would take 10 or 15 miles of driving to reach operating temp, especially in the winter. After I determined the problem, I replaced it with a stock unit. Now the engine warms up in maybe 3 miles.

 

Liquid water, which condensates in the crankcase upon cool down, vaporizes at 212 degrees. "Operating temperature" means your oil's temp exceeds the 212 degrees. If you own a newer Vette which has an oil temp gauge, you'll notice the 'straight-up' temp is 215 degrees; hot enough to cook out the liquid water from the oil. Then the water vapor is removed from the crankcase via the PCV system.

If your engine never reaches operating temp, hello sludge, hello corrosion, hello engine wear. It's why cars that only take short trips which don't allow the engine to fully warm, will have short-lived engines.

If you choose to run a 160 thermostat and you have a cooling system that's up to the task, yes, the coolant will stay at a constant 160 once warmed.

But again, your engine's oil will never reach the vapor point of water (212).

A 180 degree stat will usually ensure the oil warms to the needed level (aka, "operating temperature").

 

And you're trying to convince someone who has an original SB V8 with 212K miles on it, with only one rebuild, clean as a pin inside, and has always had a 180 or 160 degree stat in it?

[if there was a Smilie that gave the 'raspberries', I'd post it here....]