Running Hot?

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51John

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I have the '65 Valiant with a mild built 318 and the stock 2 row radiator with shroud and stock fan and no heater core...I'm running 195 to 210 degrees, a little hotter in traffic...Think that's too hot? I suppose I need to install Heater core and upgrade to a 3 row rad>. Thoughts? Thanks
 
I would have the radiator flowed and make sure it has a good thermostat.
 
What temp is your thermostat?
How many blade fan?
What is fan off of?
Auto or manual trans?
What is shroud off of?
Does temp keep rising till boilover?
 
sometimes 'mildly built' vs 'heavily modified' is not the differing factor. It's the way the engine was rebuilt that can make all the difference. A poorly rebuilt motor may run inefficiently and therefore run HOT. Just throwing that out there up front. That doesn't mean you have to go get your engine rebuilt again. It just means you may need to add more cooling capacity to compensate.
Depending on the answers to Dana67Dart's questions may determine whether an upgrade is needed and whether a 3 row copper/brass radiator is enough.

You don't want to upgrade your radiator if it is something else but you certainly don't want to purchase a middle of the road upgrade if it means having to do it again because it wasn't quite enough to solve the problem.
 
One step at a time . First : have the rad flow tested . Second : make sure the block is free of scale and rust . third : use a high flow thermostat 160-180*. Forth : high flow water pump . Fifth : clutch fan drive . Sixth : 18" steel fan . Do one at a time until problem is solved . Then and only then upgrade the radiator . Oh yeah , I forgot : fan shroud . Remember, you may not have enough volume to cool a modified engine .
 
I would flush and back flush the radiator and the Block the best you can to make sure it's clean and try a new thermostat. That's as cheapest start as you can get..
Also this is assuming your tune is correct. Timing? Carburetor?
 
51John said:
.I'm running 195 to 210 degrees, a little hotter in traffic
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If OP is running a 195 thermostat his numbers are not suprising.
IMHO....We all need some answers before offering advice.

case in point. I took my dart out yesterday, on a cool day factory guage stays near left normal mark, yesterday it was hot and guage was reading in the middle. Sitting at a light it would raise, once moving it would drop a bit. ALL very normal.
 
Thanks for the responses.. I have a unknown 6 blade fan and an unknown shroud. It's an automatic and it never boils over and never really runs cooler than 190 no matter the weather. 180 thermostat.
 
383Scampman said:
One step at a time . First : have the rad flow tested . Second : make sure the block is free of scale and rust . third : use a high flow thermostat 160-180*. Forth : high flow water pump . Fifth : clutch fan drive . Sixth : 18" steel fan . Do one at a time until problem is solved . Then and only then upgrade the radiator . Oh yeah , I forgot : fan shroud . Remember, you may not have enough volume to cool a modified engine .
Click to expand...

Before you get mad at me for this post, notice I 'agree' with you. :)

Each one of the suggestions have very good merit but unless you just plain have a BAD water pump (easy to just look in the fill neck), if you add up all the time and money it takes to do all those things, there is at least sound financial reason to at least consider replacing the radiator instead.

The first test I would absolutely do first is 'make sure the block is free of scale/rust'. No sense in upgrading anything without first making sure you are not going to contaminate the new parts with a bunch of sludge!
Then I'd add a new thermostat because it is easy and cheap. Moving forward, I'm seeing upwards of $800 in costs to do everything suggested. A new radiator is going to cost $350 at most.
 
51John said:
Thanks for the responses.. I have a unknown 6 blade fan and an unknown shroud. It's an automatic and it never boils over and never really runs cooler than 190 no matter the weather. 180 thermostat.
Click to expand...
What is the diameter of the fan? If your car never ran less than 190, that's fine. It's the 220+ temps that are just plain uncomfortable and can reduce the life of some of the engine and cooling system parts.
 
Ccas said:
Before you get mad at me for this post, notice I 'agree' with you. :)

Each one of the suggestions have very good merit but unless you just plain have a BAD water pump (easy to just look in the fill neck), if you add up all the time and money it takes to do all those things, there is at least sound financial reason to at least consider replacing the radiator instead.

The first test I would absolutely do first is 'make sure the block is free of scale/rust'. No sense in upgrading anything without first making sure you are not going to contaminate the new parts with a bunch of sludge!
Then I'd add a new thermostat because it is easy and cheap. Moving forward, I'm seeing upwards of $800 in costs to do everything suggested. A new radiator is going to cost $350 at most.
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I don't know where you're getting your radiators at, but I just got one from Summit for about $159 that's cooling my stroker just fine...
 
j par said:
I don't know where you're getting your radiators at, but I just got one from Summit for about $159 that's cooling my stroker just fine...
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I said '$350 at most' You are correct. At the bottom end of the price range, you can get a radiator that can get the job done at $159. The reason I don't brag about $159 radiators are;
1. Sometimes they don't get the job done.
2. Sometimes they don't fit
3. sometimes they don't last
4. some owners don't like putting a radiator in their car that looks like it was made in someone basement.
5. Cold Case doesn't make such a radiator.. ;)
 
51John said:
Thanks for the responses.. I have a unknown 6 blade fan and an unknown shroud. It's an automatic and it never boils over and never really runs cooler than 190 no matter the weather. 180 thermostat.
Click to expand...

If you have a fan and shroud, an important factor in how well they work together is how much the fan and shroud overlap... You want to have 30% - 70% of the fan in the shroud, the general rule of thumb is 50% of the fan should be inside the shroud...

Also make sure that you have a good seal on the radiator and fan shroud... If there are any gaps, that can be a path for the air to go 'around' the radiator fins instead of 'through' them... You want to funnel as much air into the radiator as possible... The more air that you can funnel into the radiator fins, the more cooling you can get... OEM manufacturers use rubber and foam seals to fill the gaps between the radiator and shroud to keep the air from passing around the radiator instead of through it...

You may want to try going to the home improvement/hardware store and getting some various thickness of foam strips with adhesive and attach the foam to the fan shroud to seal any gaps between the radiator and fan shroud...


Another thing that may cause the engine to run hot is ignition timing.... If the timing is off, that can cause an engine to run hot... Try bumping the timing in 2° intervals at a time to see if it helps it run better and cooler... I would try advancing it first as I've seen cars with timing too far retarded run hot...
 
OP...look at your pulleys. The water pump pulley MUST be smaller than the crank pulley. If the radiator isn't plugged, you may be turning the water pump too slow.

Always use a 2 core radiator with two big cores and not a 3 or 4 core radiator with smaller cores. Flowing water and air is what does the cooling work.
 
51John said:
I have the '65 Valiant with a mild built 318 and the stock 2 row radiator with shroud and stock fan and no heater core...I'm running 195 to 210 degrees, a little hotter in traffic...Think that's too hot? I suppose I need to install Heater core and upgrade to a 3 row rad>. Thoughts? Thanks
Click to expand...
Low speed only or hwy speeds?
Fwiw You might have a 4 blade fan and that would not be helping you at all at low speed and idle...so if that's the case, my advice is to get a 7 blade 'factory a/c equip cars had them' or just a good flex o lite that fits the shroud.
You dont need a 3 row. More rows ime are for small window core support cars. A good cross flow single row will do it.
 
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51John said:
Thanks for the responses.. I have a unknown 6 blade fan and an unknown shroud. It's an automatic and it never boils over and never really runs cooler than 190 no matter the weather. 180 thermostat.
Click to expand...

A quick test that I would recommend is when the engine is running hot, run the garden hose and spray the radiator fins with water... If the engine temp goes down 10° or more, then your radiator is not keeping up.... You may need better air flow through the radiator at idle/low speed or look into a larger capacity radiator...

Advice on radiator: Don't go with too thick with getting carried away with rows (4 row, etc...)... Rows add thickness, thickness is more resistance to airflow... Too thick can restrict airflow, so I would recommend three row and no more... You get more benefit with increasing the area vs depth if you have the room for it...
 
Heres a pic of the fan and shroud set up.

SAM_0569.JPG
 
yellow rose said:
OP...look at your pulleys. The water pump pulley MUST be smaller than the crank pulley. If the radiator isn't plugged, you may be turning the water pump too slow.

Always use a 2 core radiator with two big cores and not a 3 or 4 core radiator with smaller cores. Flowing water and air is what does the cooling work.
Click to expand...
Just to clarify, this advice applies for aluminum radiators. Copper/brass rads do better as 3 and 4 rows in that order.
 
Ccas said:
Just to clarify, this advice applies for aluminum radiators. Copper/brass rads do better as 3 and 4 rows in that order.
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True. But, if you had the choice and it wasn't a full blown resto, what would you choose, a copper/brass or aluminum radiator? Just curious, because I've been told a correctly built copper/brass radiator will actually cool better than aluminum, it just costs more and is heavier.
 
MOPAROFFICIAL said:
Low speed only or hwy speeds?
Fwiw You might have a 4 blade fan and that would not be helping you at all at low speed and idle...so if that's the case, my advice is to get a 7 blade 'factory a/c equip cars had them' or just a good flex o lite that fits the shroud.
Click to expand...

You had me until the flex fan...

I've seen and heard about flex fans coming apart... I would not use one...

Other than that, I agree with what you said...
 
yellow rose said:
From the picture, the fan looks like it's too far into the shroud. Either remove the shroud, or take that spacer off from behind the fan. The shroud can block airflow when you have th radiator that far into it.
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I would keep the shroud the way it is and make the spacer shorter....
 
yellow rose said:
True. But, if you had the choice and it wasn't a full blown resto, what would you choose, a copper/brass or aluminum radiator? Just curious, because I've been told a correctly built copper/brass radiator will actually cool better than aluminum, it just costs more and is heavier.
Click to expand...
Well, we're in the aluminum radiator business. So you know our position on this. :) This is a somewhat debated subject. I'd love to discuss but I don't want to jack this thread. I think it's a topic for a separate discussion.
 
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