In shopping for a 180 thermostat for my 455 build I see standard ones in the $7 to$10 range and so-called high performance ones offered by Summit, Jegs, etc. for 3 or 4 times that much. So, what's the claim and are they worth it? https://www.summitracing.com/search...0 thermostat&ar=1&kr=buick 455 180 thermostat
I’LL tell you one thing that’s cut in stone in terms of T stats, and that’s the BS about high flow stat’s being better! The fact is that for a motors coolant to dump heat into the Radiator it must stay in the Radiator for a certain minimal amount of time and high flow is not Guaranteed to assist in that unless you have a certain amount of excess Radiator area and air flow rate above what the motor could ever produce in terms of BTU’s.
Ray, that is like coil hype. Total BS in my opinion. Buy a name brand stat and test it before installing it if you are so inclined. A 180* stat should BEGIN to open at 180*. It should be fully open by 200*. With a good radiator, it should keep the temperature of the cooling system within 10* or less of it's rated temperature.
Thanks, Larry. Yes, I always test a new stat on the stove with an accurate thermometer. The one in my car, bought with the Cold Case radiator a few months ago, is monitored by a mechanical gauge and opens at about 180, temp climbs to about 190 and I can watch the gauge drop to about 175 before it closes down again. I bought the "high performance" one last time but think I'll just save the bucks this time around.
The more expensive thermostats used to be to ones that failed in the open position instead of failing closed so you could still limp home instead of stopped steaming along side the interstate somewhere. Buicks used to use 195 degree thermostats and chevys used the 180 degree ones. The theory was that running the engine at the hotter temperature and the internal parts lasted longer but the rubber bits like heater hoses and such life was shortened. Besides the Nickel and Chromium etc. content in the blocks cast Iron Buick 455's would run 400,000 miles on highway driving and Chevs needed bored .030 and rings at a fourth this many miles to stop the oil smoke. The theory again was the higher temperature would evaporate the water and Sulfuric acid combustion residues better. Since we now have cat cracked low sulpher unleaded 80 to 90 Octane stuf instead of the fuel 455's were designed to run on maybe the old boys theories are not in effect anymore. What do you think?
Keep in mind that the cooling system is a closed system. If you subscribe to the theory that water must stay in the radiator longer, it is also staying in the motor longer, getting hotter.
I use Safe-t-stat part number SS1800072. They run about $15 at my local NAPA store. In case over-heating does occur, they are designed to only fail in the open position decreasing the likelihood of catastrophic engine damage. I've never had one fail so I can't vouch for that claim but I can say that it appears to be a quality product and seems like cheap insurance to me.
I have gone round and on both these thoughs........its easy to follow if water passes through the radiator too fast it can't cool.........but the water passing through the motor too fast also can't pull enough heat out of the iron parts.......it physically does take time for the exchange process to happen...... Now if too slow through system you get more heat in the water and more time in the radiator to cool. So it makes sense to have a good balance. Bigger higher hp motors make more heat......but only when making that hp........a car only takes so much power to make it move at highway speeds.....so does it matter if its 600 cubes and 800 hp or 200 cubes and 150 hp. If the motor is doing 65mph it only needs so much to stay there.....if your making more your not staying 65mph. Add aluminum heads and the game changes again....change the fuel and it changes again. One of the reason alcohol runs so cold is you are burning so much more......and it takes heat absorbed in to it to switch it from liquid to vapor....that heat only comes from the intake and intake runners of the heads. The coolant has to physically be able to touch the surface to absorb or dissipate heat, this is why things like evans coolant works better.....it has a high boiling point so it doesn't flash boil as easy making tiny steam pockets causing the coolant to to be ableto contact the surfaces inside the coolant system.
Exactly right, but what has not been mentioned for a few posts is the theme of this thread, the switch in the closed system, which is the thermostat. It opens and closes to keep the engine at its 'programmed' temperature with the bimetal spring in the thermo-switch-stat, this lets the coolant in the heat sink radiator time to cool down and the coolant in the engine time to pick up the heat by opening and closing the coolant flow. So if the thermostat, water pump, fan etc. is working correctly and the radiator is designed with enough cores it really does not matter so much if you have aluminum heads, manifold etc., in theory.
So if all of that is true, then the most cooling will be with the water moving super slow. In fact let's get maximum cooling and stop the water completely, yes? Also, a second part of the question: if slowing the water results in more cooling, then how come a thermostat is designed to open as the water gets hotter? Shouldn't it close as the water gets hotter? To slow down the water?
And I'll ask you the same questions: So if all of that is true, then the most cooling will be with the water moving super slow. In fact let's get maximum cooling and stop the water completely, yes? Also, a second part of the question: if slowing the water results in more cooling, then how come a thermostat is designed to open as the water gets hotter? Shouldn't it close as the water gets hotter? To slow down the water?
You are absolutely correct, Scott. Ever notice glaciers are frozen? It's because they move so slow. And also why turtles are cold blooded. If they ran as fast as rabbits, they would burn up from overheating. Or something. (Looks at calendar to see what day this is...)
Well common sense tells you can't have no flow,........then there is no exchange to the outside. Only absorbing inside the motor.. Clearly there has to be a balance Its no difference than a pot of water over a stove or fire. Just quickly pass it over the heat not much change......leave it there and it gets too hot and boils the coolant It has to have time to exchange heat.....but to slow you get an imbalance.......cool outside and hot inside.......but too fast and it physically can't pull the heat out. Just like the pot.......but too slow and just like sitting the pot there.....the water gets to hot.
The thermostat controls the operating temperature of the system. It opens and closes in an attempt to keep the temperature as close as possible to it's rated temperature. Thermostats BEGIN to open at the rated temperature, so a 180* stats starts to open at 180*. In general, it takes an additional 20* for a thermostat to open FULLY, so a 180* stat is fully open at 200*. In my experience, thermostats are like ignition coils, lots of hype. Hi flow my butt. They open and close to regulate the rate at which coolant flows into the radiator. I doubt that rate is significantly different for different thermostats. I think it is way more important how accurately they operate, they open and close at the rated temperatures. I always hear people talk about coolant having to spend enough time in the radiator to give up heat. I think the importance of this is way overblown. The thermostat itself slows the flow, and so do the coolant tubes in the radiator. How many people run without a thermostat in an attempt to cure an overheating problem? That promotes maximum flow of coolant, but coolant can only go so fast through those relatively small tubes. I don't think heat conduction is that slow that this would make a really big difference. Running without a thermostat should cause an overheating problem because of the faster flow, but anytime I have had a stuck open stat, it causes cooler running. I think it is way more important to run as much radiator as possible, and then let the thermostat do it's job to regulate the temperature. Heat exchange is more about air flow and surface area. Brass/copper conducts heat better than aluminum, but oval tube size is limited to about 5/8" in a brass copper radiator. Aluminum is stiffer, and can support tube sizes up to 1 1/2". More surface area, and tube to fin contact means aluminum radiators perform better. One or two row aluminum radiators out perform multi row brass copper radiators.
So here's the answer: To get maximum cooling out of our systems, we want coolant to flow slowly through the radiator AND quickly through the block (very cool water moving rapidly across hot metal will carry away the most heat). How is that accomplished? Unless you have an electric water pump drive, we get what we get with water flow, determined by pump pulley speed and vanes, etc. Given the pump speed and corresponding water flow we have to live with, we want the radiator to have as much core cross sectional area as possible. This slows the water velocity through the core for a given pump flow rate (compare a core with one single soda straw size tube vs 500 sewer size tubes, one will be much slower than the other). The block passages we cant change, but more pump flow is better there. Here's another question about the thermostat opening point temperature : On a freezing cold day (like -1 deg F), why does my cooling system run right at the thermostat rated operating temp? Or little under it with the heater going full blast? And what are these implications for a cooling system with infinite cooling capacity? Or a near perfect one with water coming out of the radiator that is always 33 or 34 deg? Then extend that to a more practical situation where water is ambient.
Please excuse my lack of skills in trying to explain, I wasn't an English Journalism major. Quickly moving cool water like from a garden hose would cool down a small piece of hot Iron in a bucket quicker than no water movement, the hose would be the mentioned open system. In a closed system like in an engines where you have to reuse your warmed coolant, it has to be held in the heat sink radiator long enough to liberate it's heat or it will keep accumulating heat until the recirculating coolant boils. We add a pressure cap to raise the temperature at which the recirculating coolant boils as you know. Things just don't happen instantly, they take varying degrees of the right amount of time to work optimally, as you already knew. Larry does a very good job at explaining this situation so you don't get confused with velosity, volume and latent heat all at once. More car engines 'burn-up' from cold weather ice stopping the coolant circulation than in hot weather conditions, except in Death Valley and hell.
I can no longer tell if this thread is tongue in cheek or serious. If you have enough radiator, the stock pump will move the coolant at a sufficient rate to keep things cool. That's it. Those modern two core aluminum radiators work MUCH better than the old brass and copper originals. The thermostat, and the clutched fan, both allow the engine to quickly come up to proper operating temp and then regulate the cooling to keep things happy.
Yes I had a cooling issue once with no thermostat in place and the issue was solved once I added a thermostat so I’m convinced. I fought the overheating for a year before I was told to add a stat and it fixed things completely. No tech talk needed, it works to run a stat.
