160 or 180 degree thermostat

[Skully]

What is the best thermostat 160 or 180 degree thermostat for a 347 small block Ford. My overflow tank is full, but oil and water are about the same at 180 to 200 degrees, any ideas before I replace thermostat.

[FWB]

i run a 180, just remember its the temp it opens at, not the temp the engine runs at.

fred

[Mulv]

You should use the 160 and pay no attention to anyone who does not live where it is as hot as it is here in summer with no offence to our brother in PA. I do not have a thermostat in my 66 Mustang at all and it never overheats, even on 100 plus days because I have a lot of coolant flow. Use the 160, the car will still warm up and run fine and you will have heat in winter, assuming you have a heater . The water will stay at 160 until you overtake the efficientcy of your rad like when it is really hot or you are on the track or something. As long as the rad can exchange the heat, you will stay at a blissful 160.

It just won't be barfing its guts out on hot days...

Your overflow tank is empty when the engine is cold, right? You only have a bit in the bottom so there will be no air?

[Danr55]

I have a big block FE motor and I run a 168 t-stadt. Engine runs a constant 185-195.

[mikiec]

My 302 runs a 165

No issues

Mike

[FWB]

again the t-stat opening rating is when it opens, it will have no effect on engine operating temp. when the 160 or a 180 t-stat is open they are the same, same flow same everything. that 20 degrees your stat opens early does nothing for a hot day. your geography isn't a pertinent factor on the temp rating of your t-stat. its what the motor should have. based on the info your stating a car in north dakota should have a 300 degree t-stat. if you have hot running issues on a 100 plus degree day more coolant capacity or some anti detonation troubleshooting is in order. are you running too much CR for pump gas?, too much timing?too lean a fuel mixture? all these will play a role on how hot the motor will operate.

[DWRAT]

I had a 160 in my 347 and put in a 180 to help get the oil temps up a bit in the winter.

The 160 made the motor run to cool in the winter and in the summers it will always be open anyways.

[Skully]

The coolant is still in the overflow tank and it is to the top, it leaked a little on the garage floor. The only thing that I have done is to put a clamp to hold the small hose to the large radiator hose to keep it tight , and change the oil.

[Scotchman]

Aren't you guys concerned about the temps running too cool in the cooler months? I switched from a 180 back to the original 192 thermostat that came with my 302 in order to get the water temp back up to 192-195.

[Rick Parker]

So if an engine runs "COLD" how do you get the temp up short of blocking the radiator?
I may have TOO much radiator, that's a good thing.

[madmaxx]

Cylinder wear is 5 times greater at 160f as compared to 180f, go to performance unlimited web page and view the graph. The cylinders are cold, the pistons are hot, and bingo excessive wear. The optimium temp for combustion is 212f, look at your everyday car. Thermostats close about 10 degrees below their opening temp, so 185 thermostat is fully closed at 175, this becomes an issue in the winter when you are trying to get the engine warmed. shoot a 160 f would fully close at 150f, get ready for an engine rebuild every 6K miles.

[Danr55]

SKully, are you worried about a small amount of discharge on the garage floor? If so, don't. It's common for these motors to "puke" a bit. When the overflow stops, note the water level in the PUKE tank. That's the natural process. It would not be normal for the overflow tank to remain full all the time. The fluid has to get hot and when it heats it expands.

[Mulv]

Originally Posted by Rick Parker

So if an engine runs "COLD" how do you get the temp up short of blocking the radiator?
.

Drive faster...

To the man from PA: If it is 120 degrees outside and you are attempting to drop 10,000 BTUs from your engine, do you suspect that it would be the same transfer of heat over time as at 60 degrees below zero? It is hot here and engines run a lot hotter because the radiator is not as efficient at higher ambient temperatures then it is at the moderate coastal climate to which you are accustomed. You may recall that in the old days there were winter and summer thermostats . Why? So you would have heat in winter in your car and so that it would not fire off its radiator cap in summer... I have nothing more to say on the topic, this is simple physics. If you want to debate this any further, please start a thread and I will happily chime in. If you don't live in a climate like this, it is hard for you to see the challenges. Anyone in Central Australia, the Middle East or North Africa can join that thread as well and we can discuss it with you..

Skully: if your expansion tank is full when the engine is cold, you have too much coolant in the system You need to empty that baby down to where when the engine is hot that it is 3/4 full. That will allow for more than hot if you go to the track or drive really hard. Otherwise as the water expands , it will have to go somewhere. If it has boiled before the radiator cap can be wrecked and not release at the psi on the label. This will cause the pressure to find the next weakest link which with luck is a hose connection and without luck is the head gasket.

[Rick Parker]

Mulv: You mean lower manifold vacuum

[mr0077]

Mulv, FWB is right. The 160 degree T-stat won't keep the motor cooler than a 180 degree T-stat, and a 180 won't cause the engine to overheat. The engine will run at whatever temperature it's system reaches stability for the conditions, unless it is stable at a temperature below the T-stat opening temperature...in which case the temp will cycle up and down as the T-stat closes and opens. The higher temp T-stat just helps the motor reach ideal temperature faster, reducing wear and making the motor more efficient.

[FWB]

thanks ken, but i must say the 160 degree t-stat will make the engine be cooler on a hot summer day for about 40 seconds longer than the 180. after that i would recommend the temp gauge be put on a toggle switch. it can be turned off then the motor will be running at zero degrees, problem solved lol

[dcdoug]

MULV- FE expansion tanks have a puke hose so if you overfill the coolant, it just pukes out the excess onto the ground when the pressure builds.

[Skully]

Great answers, so should I change the radiator cap, or change the thermostat, shouldnt the fluid go back in the radiator when its cold. The overflow tank is full to the top.Coming home saturday nite it was cool out where we live, BFE AZ. IN watching the guages they all looked normal, 180 to 200 , water and oil.

[DWRAT]

Replace your cap or at least remove it and clean all sealing areas.

[Danr55]

Skully, When you shut off the engine, you stop all the cooling processes, but you don't stop the engine heat immediately. Sounds like you've simply had too much coolant in the engine to begin with. A small amout of coolant puked out of the overflow is normal. Leave it be. Don't add any more. It should be fine. The only time you need to worry is if the engine temp goes too high while you're driving.

Try using distilled water and water wetter. Perhaps a small amount of water pump lubricant. Leave the green stuff in the jug.