I have a 454 in my Caddy and I had some over heating problems. I put a Mark 8 fan on a four core radiator. It cools really well and continuously runs at 180. Except for today. It was 100 degrees so I decided to get out and test the system. I pushed it pretty hard on the freeway and it got up to 200 and took awhile to get down to 190 where it stayed. Does this sound normal for such a hot day or am I being a *****. I want it to stay at 180. Are these expectations too high for a 454 on a 100 degree day? I can still put a huge aluminum radiator on it. The radiator is stock size with 4 core.
You have to figure that if the outside temp is 80 degrees and if your car runs at 180, then if you bump up the outside temp to 100 the radiator has to get a lot hotter too. 200 is nothing. When I got my daily driver it was running at 213-215. I took it to the dealer and they said to turn off the information screen on my dash and stop watching it. Most of us grew up wanting our cars to run at 180 but the rules have changed. Don
As long as the coolant isn't boiling, it is still absorbing the heat from the engine and eliminating it thru the radiator. It's when it boils that you are in treouble, as then it no longer absorbs the heat from the engine. Boiling temp can be raised by using ethylene glycol mixed in the water and a pressure cap raises it further. The higher the pressure the higher the boiling point is raised. My OT '13 Ford Fusion with turbo carries a 21# cap!!
Expecting your cooling system to work properly seems reasonable to me. If you have a 180 thermostat and the system is running above that temp you either have inadequate air flow or an inadequate radiator....if you are having the problem while driving its normally the radiator because the fan should be off but a mechanical fan could be air air obstruction at speed. If you have the problem sitting it could be the fan, radiator of both. Swapping you old br*** 4 core for w modern aluminum radiator or similar size will gain you something like 20% more cooler capacity and probably solve you problem. I remember as a kid even in upstate NY you cold spot the cars with AC.....they were ones overheated on the should anytime traffic even slowed. The cooling systems were so marginal and all the testing done on brand new cars in the Detroit area where it's never hot. Then you let the radiator get a couple years old with the surface oxidation reducing it's capacity by 25% or so and you go somewhere warm.......not good.
^^^copper and br*** are far better heat conductors than aluminum. Nothing beats a well built multi p*** copper radiator for cooling efficiency. Going to aluminum may well be a retrograde step....
That's not quite right. Boiling water (turning water to steam) requires a LOT of energy so the water will continue to absorb heat from the engine and the rate of steam production will adjust to the rage of heat production in the engine and hole the temperature to 212 (or a bit higher depending how much coolant and system pressure you have)......as long as there is actually water in the engine. The problems come when either a lot of water has boiled or the steam has forced water out and the most critical parts like the head are left dry. At that point the heads get really hot really fast and tend to warp or crack The other thing that can happen is the water boils off leaving only coolant (ethylene glycol or whatever) left in the block and that stuff has a much higher boiling point so again the temp shoots up and bad things happen to the engine.
That's not correct. Copper is about 2 times better than aluminum but radiators are not copper, they are br*** and br*** is only about 1/2 as good as aluminum. http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html But there a more to it than that. Br*** wins in tubing wall thickness and water contact so even though it doesn't conduct nearly as well, this doesn't need to conduct as far and gets more heat to the fins than aluminum does. Then there what's called "fouling" which for auto radiator means the oxide layers that form and action taken to prevent it. Inside is about a draw with both br*** and alumin forming pretty thin stable oxide layers. Outside is another story though where br*** radiators need to be painted, paint is a pretty good thermal insulator, aluminum does not require paint because it forms a stable oxide layer...also an insulator but a lot thinner than the paint. ....and in the end br*** comes up about 25% behind aluminum performance wise.
Here's a couple good articles: http://www.caparadiator.com/aluminumvscopper.html http://www.carcraft.com/techarticles/ccrp_0211_aluminum_or_copper_radiator_for_your_car/viewall.html
I hate cars that overheat. That being said, 200 on a 100 degree day isn't bad. My '63 Pontiac Grand Prix will run at 200 with the A/C on. Normally, without A/C, she runs at 190. My '52 Chevy with a sbc and A/C runs at 200 in stop and go traffic with the A/C on. On the freeway, she runs at 180. Around town, she runs at 160. The Pontiac has a stock radiator. The Chevy, I run a copper/br*** 4 row triple p*** radiator. The Pontiac has the stock clutch fan and shroud. The Chevy has a mechanical flex fan with a full shroud.
Sorry but that is not true. A 180 degree thermostat is designed to get the engine up to 180 quickly and keep it above that temp. At 180, the 'stat is fully open and is doing what it is supposed to do. If the engine gets below 180, the 'stat starts closing and warms the engine up again. The rating on a thermostat is the lowest temp the engine should run, not the highest. If you want to keep an engine below 180, run a 160 'stat. That is no guarantee the engine will stay that cool but definately make sure it never gets below 160. An engine that runs a 180 thermostat and gets to 200 after dogging it on a 100 degree day is doing just fine as long as the engine was designed for that temp, which a 454 was. Most newer 454 (around 70 or later) would have come with a 192/195 degree thermostat. Higher temps came along to reduce emissions.
While copper br*** may be better heat exchangers, the construction of the radiator and the number of fins per inch has a lot more to do with its cooling ability than just the properties of the metal. Modern aluminum radiators have a lot more fins per inch than the comparable c/p units.
Neither the OP, nor any responders has mentioned a shroud. Louie T, if you aren't using a fan shroud, buy or make one. Then position the MECHANICAL FAN (this is the HAMB, after all ) so it's half inside the shroud and half outside.
The thermostat controls the low as you say, then the burden shifts to the radiator which controls the high. If you want the car to run at 180, the first thing you do is install a radiator large enough to maintain a max temp of 180, then you add a thermostat to ensure it can actually reach 180. Once it's warmed up, the only temp you should see on the gauge is 180 and if you are seeing something different the cooling system is either broken or poorly designed. The way to think about is a t'stat is a control device and once it's fully open it has lost control of the system.....and nobody wants a system that is out of control. Luckily cooling systems are inherently stable meaning that when the t'stat looses control and the temp starts to rise, that causes the heat transfer rate in the radiator to rise and the system will come back in balance and run just run away....at least not until the water boils out then it will run away. If the system is getting to 200F all by itself in normal operation then it's pretty close to trouble and I'd be pretty worried about what would happen when you get it up to 200 on the highway then hit rush hour traffic.......I'd want to fix it I think.
as Just Gary said, fan have full shroud if behind radiator. run mechanical fan if with thermal clutch if you have the room. what coolant mix running? replace thermostat with a "big mouth" that allows coolant to flow better. what is rating of radiator cap? is engine compartment sealed up or, are is there a way for hot air to escape? have overflow tank?
The only thing that's bugging me, (I won't go into my hatred of electric fans) is the fact that it was heating up on the freeway at continuous speeds. That kinda tells me that maybe not all of your cooling air is going through the radiator. Do you have any gaps ahead of the radiator where air could by p*** it and go around or over? If you do figure out a way to plug those gaps up right now.
The bottom line is your car is NOT over heating. 200° and the ability for it to come back to 190° is absolutely fine and yes even for older motors. take a look at my thread for some more information - http://www.jalopyjournal.com/forum/showthread.php?t=812968
I have a shroud and like I said I'm running the Mark 8 fan that comes in a single shroud/fan unit. I can't fit a mechanical fan in there because the 454 is a monster. I do plan on eventually running a bigger aluminum radiator but I was troubled by the fact it got up to 200. When I got off the freeway it started to cool down so I know the system is working but I want it to work faster and better. Like I said, maybe I'm being a ***** about all this and it's working fine. I plan on running a condenser in front of the radiator and I'm sure that will complicate things a bit as far as air flow goes. I failed to mention that I have a big trans cooler on front of the radiator and that thing gets to 160-180 easily. Can I move it away from the radiator? I was thinking if even putting a small fan on it but keeping it away from the radiator. Once again guys. Thank you for all the input.
Going to 200F is fine if that is the design set point...but it sounds like the design point is 180 so the system is overheating...and that is under what appears to be very moderate usage so actually pushing the car a bit would cause the cooling system to fail. As several have said, it's not going to harm the engine and its not an urgent issue to deal with as long as the car is usage conditions are controlled and you keep an eye on the gauge......but it's certainly not working correctly because you should be enjoying the drive, not wondering what how high the engine temp is going to get today
Update on the sitch...it was a beautiful balmy 101 degrees in the IE today so I thought I'd run a few heat tests. I moved the ****** cooler off of the radiator and mounted it on the side behind the grill so it could still get a nice airflow. The ****** ran a little hotter compared to when it was on radiator but only in stop and go traffic. It got to 185 in traffic and back down to 170 on the freeway. The engine temp was a whole different story. Around town it got to 181 but only for a short minute and stayed between 180-190 on the freeway. The ****** cooler was my weak link and hopefully I'm cured of my heat demon. I plan on running AC on it soon. Anyone have any input on what complications I might have with a condenser in front of the radiator. I plan on running the Vintage Air system. Once again, Thank You everyone for your input. It was greatly appreciated. Lou
This ^^^...especially considering that when you moved the trans cooler, it didn't run as hot on the freeway. But when you mount your condensor, you'll have the same issue. As NL said, close any openings around the radiator. Even with an obstruction such as the trans cooler or condensor, the pressure build at speed will force the air to go through the radiator...if there's nowhere else for the air to go. Also, a flap or two on the shroud will help. Both mechanical and electric fans can be inhibit airflow at higher speeds. Flaps on the shroud will open at higher speeds to allow the air through more easily, yet seal the shroud when the fan is needed around town. Doing this might make a new radiator unnecessary. But doing this along with a new radiator, and you'll surely see an improvement.
Back in the old days, it was considered "normal" for the water temperature to run 5-10 degrees above the thermostat rating. Any time the outside temperature was above 100 degrees, an additional 10 degrees above the "normal" was no unexpected. The location of the coolant sending unit on the motor makes a big difference on what the temp reads on a gauge compared to what the thermostat opens at. Electric fans all have a sensor to turn the fan on and off. Where that sensor is located will also effect the coolant temp. Air flow through the engine compartment will also effect the coolant temp, if the heated air can not get out of the engine compartment fast enough, the cooling system can not function correctly. The speed the vehicle is moving will also have an effect on how much air is p***ing through the rad, a faster moving vehicle can force more air though the rad then a slow moving vehicle, providing nothing is interfering with the air flow. To ***ume a bigger radiator, a bigger electric fan, and a certain mixture of coolant/water will solve all overheating issues shows inexperience in the real world. Gene
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