Overheatling temp range
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Joined: Aug 2007
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From: Glendale California
Overheatling temp range
I just installed a new Dewitt stacked aluminum radiator. I have a 65, 327, 350HP that always ran hot. The temp guage was always showing past 240* before the new radiator. Now at low speeds its around 230*. At high speeds its around 220*. I have changed 2 sending units, but plan to buy another one from Auto Zone ( Wells TU5) and hope this one will work. I have also checked the temp. with I.R. gun at the thermostat housing while parked and the engine running 210*. Is 210-215* too hot? The ambient temperature was 72*.
Team Owner
Joined: Mar 2002
Posts: 44,681
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From: Huntsville AL
I have the same setup as you and run 180 deg on the gauge and when using my IR gun have 182-185ish at the rad inlet and 165-170ish at the rad outlet.
One thing I did learn in all this is that the $35 IR guns are best used when shooting into a black surface about 1" away. I point the gun 1" away from the rad inlet and outlet.
I would think your car would be puking at 240 so my guess is your temp gauge is not reading correctly or there are other problems in the cooling system.
One thing I did learn in all this is that the $35 IR guns are best used when shooting into a black surface about 1" away. I point the gun 1" away from the rad inlet and outlet.
I would think your car would be puking at 240 so my guess is your temp gauge is not reading correctly or there are other problems in the cooling system.
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Joined: Aug 2007
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From: Glendale California
I have a brand new high flow water pump with its corresponding 160* thermostat. New fan clutch, Fresh premixed coolant, a new tank cap, and a new radiator. After all this, its still running at 210* at the termometer housing and if measured at 1 inch away it adds another 5*. I am very frstrated with the cooling system. I keep throwing money at this problem but it just wont go away. 
Former Vendor
Joined: Jan 2000
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From: Brighton
Very Important! This will make you run hotter than normal at idle and low speeds. You might have the correct one but the diaphram could be cracked and not functioning. Check to see if you get 12-15 degree additional when hooking it up. If that's ok, then let's take a look at the other stuff. The high flow water pump may actually cause more problems than it solves. I have had many people tell me that adding a high flow pump made the engine run hotter. The 160 stat does nothing for running cooler, so I'd change that back to a 180.
Do one thing at a time, and log the results. Instead of the hassle of changing the pump back, you could install a restrictor plate to see what happens. Every radiator has an optimum cooling flow point. To much low or too little flow and you will reduce the performance.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
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From: columbus oh
you are running too hot. assuming everything in the cooling system is ok....check the advance curve and the vacuum advance unit. could also be a head gasket or a loose hose clamp on the suction side of the water pump----loose clamp lower hose---bad internal spring lower hose----heater hose clamps on return ( 3'4) hose loose at core or pump..good luck and hang in there
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Joined: Jun 2006
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From: S.F. ( E. Bay) Calif.
Check thermo before replacing
If you replace the existing thermo and install a new 180 deg., as Tom suggested, put them in hot water on stove, before installing, and confirm they are operating. You can put a thermometer in water at same and see at what temp they respond. It will tell you if you old one was working and confirm if your new one is before installing it.
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I have a 65 300hp car. And my overheating problems, and attempts to repair mirror what you have done. I added a digital temp. gauge which confirmmed my original gauge was about 40 degrees off reading to high. But even the digital gauge still reads 210-220 degrees. My block was overbored .060 and I've been told that's way it runs in that temperature range. These temps scare me, so I can only drive the car in the spring and the fall.
Lowell
Lowell
Le Mans Master
Joined: Nov 2000
Posts: 7,246
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From: Going too fast over the hill. Iowa
If the wire to the sender is laying on the head or intake manifold, move it or wrap it in an insulator - then see if the temp gauge drops.
Does your car have Powerglide?
Does your car have A-C?
Does it have the shroud in place and sealed?
If you have a clutch on the factory fan have you tried eliminating it to test the air flow?
Get out your timing light:
1 What is the initial advance at idle with vacuum can disconnected and vacuum hose plugged?
2 When you reconnect the vacuum advance what does the timing light indicate the advance is at idle?
3 What total advance does a timing light show when you rev the engine?
Do you have the lower shields in place on the engine compartment? They can restrict high speed air flow.
Does your car have Powerglide?
Does your car have A-C?
Does it have the shroud in place and sealed?
If you have a clutch on the factory fan have you tried eliminating it to test the air flow?
Get out your timing light:
1 What is the initial advance at idle with vacuum can disconnected and vacuum hose plugged?
2 When you reconnect the vacuum advance what does the timing light indicate the advance is at idle?
3 What total advance does a timing light show when you rev the engine?
Do you have the lower shields in place on the engine compartment? They can restrict high speed air flow.
Race Director
Joined: Nov 2002
Posts: 12,142
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From: Taylor Michigan
Very Important! This will make you run hotter than normal at idle and low speeds. You might have the correct one but the diaphram could be cracked and not functioning. Check to see if you get 12-15 degree additional when hooking it up. If that's ok, then let's take a look at the other stuff. The high flow water pump may actually cause more problems than it solves. I have had many people tell me that adding a high flow pump made the engine run hotter. The 160 stat does nothing for running cooler, so I'd change that back to a 180.
Do one thing at a time, and log the results. Instead of the hassle of changing the pump back, you could install a restrictor plate to see what happens. Every radiator has an optimum cooling flow point. To much low or too little flow and you will reduce the performance.
And put a 180 thermostat in the engine and dump the 160.
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
I have a 160F tstat in my 1966 with Stewart high volume pump. The temp doesn't get above 170F unless the A-C is running on a 100F day, and even then it doesn't get above 185 on the highway or in city traffic.
A 160F tstat does not make the car run hotter, and in my experience neither does a Stewart high volume pump.
A 160F tstat does not make the car run hotter, and in my experience neither does a Stewart high volume pump.
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
I have a 160F tstat in my 1966 with Stewart high volume pump. The temp doesn't get above 170F unless the A-C is running on a 100F day, and even then it doesn't get above 185 on the highway or in city traffic.
A 160F tstat does not make the car run hotter, and in my experience neither does a Stewart high volume pump.
A 160F tstat does not make the car run hotter, and in my experience neither does a Stewart high volume pump.
MagicV8,
If my memory is correct you have a big block (not the sb the op is talking about) which originally came with a copper radiator, and then you upgraded that to an aluminum radiator.
If that's correct then your application is different. The replacement aluminum radiator has about 30% more cooling tubes than the copper one originally installed and therefore the peak water flow for that radiator would be higher. In your case, the higher flow water pump is actually an upgrade because you matched the radiator and the pump.
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
MagicV8,
If my memory is correct you have a big block (not the sb the op is talking about) which originally came with a copper radiator, and then you upgraded that to an aluminum radiator.
If that's correct then your application is different. The replacement aluminum radiator has about 30% more cooling tubes than the copper one originally installed and therefore the peak water flow for that radiator would be higher. In your case, the higher flow water pump is actually an upgrade because you matched the radiator and the pump.
If my memory is correct you have a big block (not the sb the op is talking about) which originally came with a copper radiator, and then you upgraded that to an aluminum radiator.
If that's correct then your application is different. The replacement aluminum radiator has about 30% more cooling tubes than the copper one originally installed and therefore the peak water flow for that radiator would be higher. In your case, the higher flow water pump is actually an upgrade because you matched the radiator and the pump.
When I get more time Ill look for the BTU numbers that you gave me.
If you ae really saying that the rad with the bigger tubes NEEDED a higher flow pump to match the coolant flow capacity of the rad and optimize heat transfer. I can agree with that. The Stewart pump may be a closer match to the BB pump in terms of flow.
The fact remains that my car is now able to operate with the A-C system pumping heat out o the cabin and into the front of the radiator under all the conditions I encounter.
Last edited by magicv8; Dec 8, 2008 at 05:45 PM.
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
If my memory is correct, you told me that your SB repro rad had a lot more heat transfer capacity than the aluminum BB rad that you sold me.
When I get more time Ill look for the BTU numbers that you gave me.
If you ae really saying that the rad with the bigger tubes NEEDED a higher flow pump to match the coolant flow capacity of the rad and optimize heat transfer. .
When I get more time Ill look for the BTU numbers that you gave me.
If you ae really saying that the rad with the bigger tubes NEEDED a higher flow pump to match the coolant flow capacity of the rad and optimize heat transfer. .
What we claim is the SB factory aluminum radiator has a higher btu rating than the stock COPPER radiator, not the upgraded aluminum one you have. That one is higher.
And I'm not saying that upgraded BB radiator NEEDED a bigger pump, I'm saying it will show an addition benefit with one but the upgrade without adding the pump is typically enough.