temp drop across radiator
Instructor
Joined: Mar 2005
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From: Perkasie PA
Durango Boy - that makes sense. What I struggle with is why when I walk through a parking lot on a hot day and I walk past a car with a fan running and the car off the hot air is blowing on my leg. I am almost certain my '90 Corvette fan blew outward also.
I am going to check mine and I am going to reverse it to see what happens for the sake of knowledge versus guessing.
Good thread but still a lot of BS floating around on this subject.
I am going to check mine and I am going to reverse it to see what happens for the sake of knowledge versus guessing.
Good thread but still a lot of BS floating around on this subject.
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From: hernando fl
the car that started this whole debate is a 4 speed,so no tranny cooler is involved. i have also read and reread a lot of the posts . i think there is some truth in the too much flow theory. however i think it would take an extraordinary set of circumstances for that to be the silver bullet and cure everything. and i also agree there is a lot of BS on this subject.if time permits ( lots of obligations this weekend) i will put the thermo couples back in and take some serious notes on what exactly the temps are at the rad inlet ,outlet and t stat housing. as near as i can tell the temp stays around 180 to 185 all the time A/C on or off , at cruise and idling at a traffic light. in my opinion very very good for muggy sout fla days.
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From: hernando fl
i guess i didn't reread everything.............the overheat on this car is now fixed,it was the lower rad hose , spring insert was missing & being sucked down and causing a restriction,but i will do the thermo couples and provide some hard numbers on what is going on in the radiator.
Tech Contributor
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
i guess i didn't reread everything.............the overheat on this car is now fixed,it was the lower rad hose , spring insert was missing & being sucked down and causing a restriction,but i will do the thermo couples and provide some hard numbers on what is going on in the radiator.
Melting Slicks
Joined: Jan 2003
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From: Doha
St. Jude Donor '08
i guess i didn't reread everything.............the overheat on this car is now fixed,it was the lower rad hose , spring insert was missing & being sucked down and causing a restriction,but i will do the thermo couples and provide some hard numbers on what is going on in the radiator.
I agree with mrvette, if you use a high-volume water pump then you must use a balanced thermostat. I upgraded to a HV water pump from Stewart in my BB and left the un-balanced stock thermostat, it had the same symptoms as you described in your original post, but when I replaced it with a balanced thermostat from Robertshaw , the problem was fixed right away. I strongly recommend to have a balanced tstat if you have a HV water pump. Also don't forget to drill a 1/8 whole in it to release air pockets.
Team Owner
Joined: Jan 2006
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From: Crossville TN
I'll close my remarks on this topic by stating the following....
You can have too much pump flow through a system and it will cause excessive pump heat from doing unnecessary work and generate turbulent flow (at restrictions); all of this will cause elevated temps from what should be the normal operating temperature. You can have too little pump flow, which will also cause excessive operating temperatures. Hence, my original statement which was that "..the pump used must match the needs of the cooling system". A cooling system and its components must be matched; if they aren't, it won't work properly.
You can have too much pump flow through a system and it will cause excessive pump heat from doing unnecessary work and generate turbulent flow (at restrictions); all of this will cause elevated temps from what should be the normal operating temperature. You can have too little pump flow, which will also cause excessive operating temperatures. Hence, my original statement which was that "..the pump used must match the needs of the cooling system". A cooling system and its components must be matched; if they aren't, it won't work properly.
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From: hernando fl
i agree with what 71vette said ,bottom line is the components & system must work together. if i have learned anything from all this ( and believe me i have learned a lot) putting a hi flow pump or an electric fan or whatever the "cure" is thought to be...even if it does fix the problem , it is probably just a band aid on a larger SYSTEM malfunction. these cars functioned as they were delivered from general motors , no hi flow pumps,giant aluminum radiators, electric fans ect. i spent a lot of money and a lot of time chasing rainbows overlooking that fact.
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Melting Slicks
Joined: Mar 2002
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From: Ohio
My stock small block with a new recored copper radiator and stock fan on a hot day was running 210 on the gage. At an idle back home I had 195 on the top tube on the radiator and 162 at the bottom tube with my infa red gun tester. I now know I have a gage problem but thease numbers could give you an idea of the drop on a good system.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
i agree with what you said 7t1vet. what you said was great first up checks and kind of just got repeated . i wouldnt have said quote" going through all that stuff " after going through all the stuff that sixfooter and 7t1 said and it fails put your hand in front of you ac condensor ..your fans should be powerfull enough that you feel the air being sucked in through the front. also you running a 502. that requires a radiator that is sufficient for that motor. you say its an alloy but dont even know what type it is. could be a skinny barely good enough 2 core for something else..i would be looking into that.
It is that simple, BeCool sells three different systems, one for 400HP, one for 700HP and one for 1000HP. There is a reason they do this, why don't they just have one system sell that to everyone ?
Our C3's especially the later ones have cooling systems that were equipped to handle 200HP. Now when we put a 500HP motor in there we wonder why it over heats. You have to buy a good radiator and good electric fans
Last edited by MotorHead; Jul 26, 2008 at 11:20 AM.
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From: hernando fl
i should have been a little more specific , i agree bigger engines than stock and higher hp than stock need special consideration. however a bone stock car should function normally without all the high dollar after market "fixes" providing all the components of the system are in good condition. at least in my mind a stock 454 cooling system should be able to handle a 502 99% of the time. i am almost certain i will get flamed for this but here goes....cruising down the road @ 45 mph A/C on requires a certain amount of HP, that amount of HP generates a certain amount of btu's,the cooling systems job is removing btu's. so in theory at least a 150 HP 6 cyl is generating the same amount of btu's as a 500 hp 502 in the example above.maybe not identical but very close.so the cooling system should be adequate. the problems arise when the 502 gets tapped for more HP (btu's) than the system was originally designed to handle.
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From: Orange Park Florida
That is the best advice to anyone running a high HP or bigger motor, get a cooling system designed to handle the motor you have.
It is that simple, BeCool sells three different systems, one for 400HP, one for 700HP and one for 1000HP. There is a reason they do this, why don't they just have one system sell that to everyone ?
Our C3's especially the later ones have cooling systems that were equipped to handle 200HP. Now when we put a 500HP motor in there we wonder why it over heats. You have to buy a good radiator and good electric fans
It is that simple, BeCool sells three different systems, one for 400HP, one for 700HP and one for 1000HP. There is a reason they do this, why don't they just have one system sell that to everyone ?
Our C3's especially the later ones have cooling systems that were equipped to handle 200HP. Now when we put a 500HP motor in there we wonder why it over heats. You have to buy a good radiator and good electric fans
Drifting
Joined: Aug 2005
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From: League City TX
It is that simple, BeCool sells three different systems, one for 400HP, one for 700HP and one for 1000HP. There is a reason they do this, why don't they just have one system sell that to everyone ?
Our C3's especially the later ones have cooling systems that were equipped to handle 200HP. Now when we put a 500HP motor in there we wonder why it over heats. You have to buy a good radiator and good electric fans
Our C3's especially the later ones have cooling systems that were equipped to handle 200HP. Now when we put a 500HP motor in there we wonder why it over heats. You have to buy a good radiator and good electric fans
A 700hp motor will generate more heat than a 300hp motor, when you are beating on it.
At idle or at 55mph though, heat production should be pretty similar.
A properly working stock cooling system should be able to cool most cars during normal operation, no matter what hp the engine could potentially make.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
While that is certainly correct, its not totally applicable to cars that overheat at idle or low speeds.
A 700hp motor will generate more heat than a 300hp motor, when you are beating on it.
At idle or at 55mph though, heat production should be pretty similar.
A properly working stock cooling system should be able to cool most cars during normal operation, no matter what hp the engine could potentially make.
A 700hp motor will generate more heat than a 300hp motor, when you are beating on it.
At idle or at 55mph though, heat production should be pretty similar.
A properly working stock cooling system should be able to cool most cars during normal operation, no matter what hp the engine could potentially make.
Drifting
Joined: Aug 2005
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From: League City TX
But wouldnt you agree that it takes the same amount of hp to push a car down the road at 55mph, no matter what the engine is capable of?
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From: hernando fl
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
You guys go ahead and do what you want, I can't waste any more time on this
Melting Slicks
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From: Doha
St. Jude Donor '08
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From: Scottsdale Arizona
I think in this example it would be about efficiency. A higher HP motor is less efficient at low loads, hence why it burns more fuel even when not driven like a solen car. In your example, while it only needs the same HP for the same weight car at the same speed, it will generate more waste heat.
That is the reason for some of the engines that "switch off" cylinders for greater fuel efficiency at highway cruising speed. Less fuel used and, as a byproduct, less heat generated.
Regarding the question of flow rates through the radiator, I don't think that any pumps on the market are capable of taking these systems to a point where efficieny diminshes. There certainly is such a point, but we won't get there even with high flow pumps. I forgot who said it earlier in this post, but I agree. You will not make a problem worse by increasing the coolant flow. May not fix it though.
That is the reason for some of the engines that "switch off" cylinders for greater fuel efficiency at highway cruising speed. Less fuel used and, as a byproduct, less heat generated.
Regarding the question of flow rates through the radiator, I don't think that any pumps on the market are capable of taking these systems to a point where efficieny diminshes. There certainly is such a point, but we won't get there even with high flow pumps. I forgot who said it earlier in this post, but I agree. You will not make a problem worse by increasing the coolant flow. May not fix it though.
Last edited by CA-Legal-Vette; Jul 26, 2008 at 11:41 PM.