Waterless coolant has a boiling point of 375 degrees. What temp does a engine start to do damage? Cracked heads or block, blown head gaskets?
Though I am not sure of the exact degree at which she'll blow, I do know for a fact that is slightly less than I think she will hold.
I'm puzzled by the question. You don't want a cooling system that operates at anywhere near that temp. But nobody wants to be stuck on the side of the road boiling over, so I guess if you just need a little extra headroom until you can get somewhere to fix the actual problem.
NOTHING's changed..! I'd imagine if you noticed a temperature of...say...230° in your engine...you may want to stop and find out...what the problem is..! Overheating has nothing to do with the coolants boiling point..! While this stuff won't be squirting out of any place like water will, it still not a good idea to run a street engine much over about 230°/235° F. The head gaskets may not like it much. Also, while it's not a killer to run that hot because the coolant will / should stay within the coolant system, 99% of the engines on the road were not designed with the parts that a NASCAR (as noted above) engine was..! Do you worry about your brake fluids boiling point ? Do you have a temperature gauge in your brake system ? I'd bet you didn't even know this is a thing for brake fluid. I'll bet you don't even keep an eye on the brake fluid or is last change period... Mike
Newer cars are designed to run at temperatures that would scare the hell out us in our hot rods. The high temperatures are for emission control for the most part. Sent from my iPad using The H.A.M.B. mobile app
Why worry????? the temperature of the engine is controlled by the thermostat, and partly, by the radiator cap (pressure relief)
LMAO I know right? The boiling point of your coolant is a non issue. you still need to maintain proper operating temperature for your engine.
I remember some ads from several years ago. A company was advertising in car mags about the benefits of running an engine at very high temps, and their new coolant was the ticket. A couple mags wrote articles of the benefits of super high engine temps. 1990s? Then it was never talked of again. I dono why they promoted such high temps unless it was to brag about the product endurance. Oil temps always seem to work their way up to general engine temps, then go above.... If you run 240+ coolant temps, what are you doing to oil temps which climb even higher as you work the engine over long periods? I had to install some large engine oil coolers on some caddy engine swaps. Even tho the coolant temps never blew the rad caps, often the oil temps headed for 300 range, measured in the pan, and one rattled a brand new crank on a long trip before I put in gauges to monitor the causes. After oil cooler installation, no more probs. I can't imagine trying to "take advantage" of super high temps without concern over the disasterous high-temp effects on everything else. cooking starters, cooking gaskets, softening bearings, hot oil, .... I have expended lots of time and effort trying to protect everything from heat's bad effects- from wrapping sections of pipes that run past starters, installing small sheetmetal shields n air deflectors to direct cooler air to sensitive items.... If you have ever discarded any small thin " unneeded splash shield" near a factory fuel pump or near a starter, you may have disrupted a factory fix for a hot area that needed a cool air deflector or hot air redirection. Mysterious vapor lock probs or short starter life can be something simple like a missing small tin plate or disturbance in the factory "air wash" over the engine critical areas. I cannot understand wishing to make the problems worse... WHY BE ORDINARY ?
The Nascar stuff, while interesting, does not apply to most of our hotrods: * They run straight water and a minimum 30 psi relief valve. At sea level that puts water boiling point at 265 degrees F. * Many teams run 50 to 65 psi relief valves to run in the 280 to 290 degree F range. * High water temp requires less radiator air flow, hence more tape can be run on the grill to get more aero. * And they have big oil coolers.
A properly designed cooling system does not require Snake Oil. 50/50 water and antifreeze is whats normally required.
Think of it this way. At the point your engines coolant system becomes too hot, you have time to stop the car and shut the engine off . Let it cool and add some coolant. If you raise the boiling point of the coolant, you put every moving part and many non moving parts at risk as you continue to drive. Even if your engine doesn't fail at that point, you probably have affected the future point of the engines lifespan.
This is a good point, and I hope you don't mind if I elaborate a little on it, and I'll try not to geek out too much. There are 2 dangers with elevated temps, Oxidation & Thermal Degradation. Oxidation is the normal aging process of oil, it is ongoing all the time, but the process is accelerated by heat. Following the Arrhenius Rule, the rate of oxidation doubles for every 10*C increase in temperature, leading to lacquer and varnish formation, and eventually sludge; as well as acids that attack soft metals, and the oil thickens in viscosity. The temperature that this becomes problematic varies with the oil in use and with the time at temp. Extended or constant use at elevated temps will drive the process. But I would say above ~ 250*F constant the oil is going to degrade mush faster. By 300*F, whew, that's putting a lot of stress on the oil, it's going to oxidize quickly. Thermal degradation happens at hotter temps, say around 400*F. Get it hot enough ands the hydrocarbon molecules will actually crack, and some of you have probably seen the results, especially in turbocharger oil passages. It's a dry, caked substance. The results of thermal degradation are similar to oxidation, dark, thick oil, w/ lacquer, varnish and sludge, along with a strong odor, but the cause is different. Either way it's not good, and heat is the enemy. note: synthetic oils are more resistant to both oxidation and thermal degradation, but all oils will eventually age or crack at high temps.
To add to the problems listed from heat, obviously an engine is designed with a range of optimal clearances between moving parts at a range of acceptable temperatures. Heat is going to close up those clearances, perhaps to zero...
A big issue with hot gasoline engines is detonation. Oil coking is another (coke is the term for the carbon created when something breaks down from heat without igniting). There were numerous experiments with adiabatic engines in the 80's to improve fuel efficiency. It works better with direct injection or diesel engines to avoid the detonation issue. Ceramics were often employed to avoid burned pistons and exhaust valves. I remember the Smokey Yunick "hot-vapor" engine articles from that time. https://www.hotrod.com/articles/hrdp-1009-what-ever-happened-to-smokeys-hot-vapor-engine/
To elaborate on what Blues4U said, and based on past work experience. Oil temps approaching 350 F generally equate to engine life measured in minutes. I used to be the lead Test Engineer at an ATV and Side-by-Side OEM. We would do high speed / high load endurance tests on a chassis dyno or out in the desert southwest. I am talking test cycles of 40 minutes of WOT in sand followed by 10 minutes of hot idle, then repeat multiple times with no shut down time, during the peak heating hours around Yuma, AZ. More then enough to find the limits of your cooling system. The coolant temp could be controlled easily enough with the right sized radiator, the oil temp was much more difficult. I am personally responsible for many a dead engine. We found out quickly that an engine was toast if we saw oil temps approach 350 at the dipstick. Con-rod bearings always seemed to be the first to go.....
My buddy has a OT Corvette with a digital dash. I was driving it one night and the water temp was 217.. I asked if that was normal and he said yes. Most new cars are designed to run as high as 220-230.
I have been using Evans wateless coolant in our altered "The Hilltown Shaker " for the last two years. Our car has no cooling system at all just filled with coolant and heat soaks in the block and heads. With it being alcohol injected we usually are able to drive to the lanes and back to the pits after a run . It is jetted fat and actual will drop temp during the burnout .A few years back when we hot lapped at the later rounds the car got really hot and was filling the overflow tank, i went to a 30 lb cap and it was only a little help, since switching to the waterless coolant we have hot lapped it multiple times (less than 20 minutes betwen rounds) and even once this summer left the line at 240 deg. it never boils over and we have no issues with the oil at all. I change the oil for every race but comes out clean and the engine is perfect inside, I save the oil and ues it in the tractors at my farm. I run Valvoline synthetic VR1 20-50 . There is no corrosion since changing to it and i am very happy with the switch. it also i believe is the only NHRA approved coolant that can be used during competition . I drained it out and reused same coolant two years in a row
Those of you wondering about the 375° figure and Evans waterless coolant and how it pertains to internal combustion engine heat should Google "nucleate boiling" and learn how 180-230°+ bulk glycol/water coolant temperature doesn't encompass what can be going on in the backside of the water jacket surface just above the chamber and exhaust port in the cylinder head.
Grandma used a pressure cooker when canning 'cause up here in the mountains water boils at less than 212 degrees. Without pressurizing the water it would boil off before reaching safe bacteria killing levels. She had little weights that sat on top of the pot that served as pressure relief valves. The heavier the weight the higher the temp could be without boiling. Boiling liquids make lots of bubbles. When bubbles form in your engine they aren't all circulating. Some adhere to the walls and some are trapped. Where ever there's a bubble there is NO WATER or COOLANT TOUCHING the HOT BLOCK. If the bubble moves it's like throwing water on red hot cast iron. A higher pressure cap, like granny's heavier weights, will allow higher temps without boiling (beware your old low pressure heater cores). The richer your coolant mix the higher temp you can go without boiling, to a point of course. A very rich mix of antifreeze WILL burn.
That’s an incorrect interpretation if I am understanding what you are saying. There is relatively little heat transfer from the metal to the coolant until you reach the phase transfer temperature where nucleate boiling occurs. It’s this phase transition that keeps critical engine components within the thermal limits of the materials. Examples of places that rely on nucleate boiling are valve bridges in a cylinder head. The bulk temperature of the coolant will be relatively low throughout the engine, but local critical areas rely on the energy transfer to control metal temperatures.. consequently, these magic coolants effectively hurt heat transfer and would be detrimental to engine life.
I don't see how boiling water in a closed engine is good for it, "nucleate" or not. If I had to run an engine with no pressure on water at 213 degrees sea level for 500 miles vs an engine running a coolant with a boiling point higher than 213 I think I'd be better off.
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