Classic industries radiator finally gave out

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So everything was working just fine then, the radiator just sprung a leak.

I measured the core thickness on my Champion 26” 3 row, it is in fact about 2.5”. Tanks are 3”. Currently I’ve got ~9/16” from the end of my pulley to the fan shroud for my electric fans, so, a 2.75” core would be a no go for me. Hopefully you’ve got the room!

I measured the thickness, from the core support my current radiator is 3” deep. The new radiator is 3” deep. My current radiator appears to have a 2-1/4” core, but the core is offset towards the fan, the core is about 3/4” inset from the front but is flush with the back. I should have plenty of room but we shall see
 
Ok guys well i suppose its time, ran her on sunday and of course the classic industries radiator appears to be leaking at the bottom tank on the drivers side. I guess not too bad for about 8 years old. Not pouring but enough to notice, guess its time to go aluminum. I contacted wizard cooling and they recommended to go with the 1.25” tubes over the 1” they told me anything at or over 400 hp they recommend the 1.25” tubes.

Dang you got 8 years out of it? I couldn’t even get 8 months with my stock 318 daily driver lol. My buddy didn’t even get a year with his on his 170 slant six
 
Just a thought but why not find the leak (pressure test it) and repair it with a propane torch, solder. There are like chains they break at the weakest link. I have repaired rads (for pennies) decades ago because it took less time than finding a replacement and they still hold pressure today.
 
What is the downside to two 1.25 inch tubes? Th answer is nothing. I’d ditch the clutch fan long before i skimped on tube size. There is no downside to bigger tubes.
I would never ditch the clutch fan to gain radiator core clearance. The OEM 3 core narrow brass/copper is enough cooling for an A-body 426 HEMI, and enough for a 340 A-body with A/C. The clutch fan and proper shroud are the secret to proper cooling and don't steal 20 HP and make a bunch of noise in getting it done. I'm currently using the original 53 year old three core mopar radiator in my 69 Barracuda to cool a stout 468 automatic with A/C. It has proved to be capable up to air temperatures of 95 degrees in traffic with A/C on. Maybe 100 degrees would exceed its capability but seldom do we see such temps in mid-Michigan.
 
I agree, there is engineering that goes into it. If the OP is short on room two 1 inch tubes is LESS thick that your .75 3 core and it will flow more coolant at the same pressure and pump speed.

Two 1 inch tubes will cool way more that what the OP has IF he has thought out the rest of the cooling system. That means a quality high volume water pump, over drive pulleys and a decent fan. If anyone has that, two 1 inch cores will cool way more than what is claimed.

Fins per inch has its limits as well. Get too many fins per inch and you can’t get enough air through the radiator to cool anything. Too few fins and you can’t dissipate the heat quick enough.

I forgot to mention you also need a quality high flow thermostat. The only thermostat I’ve found that is always fully open by it’s rated temperature is the Robert Shaw/Stewart Components thermostats.

I just had a Pontiac guy call me on Monday and his engine runs at 192-195 a 180 thermostat. So I had him pull it out and verify when it opened. And sure enough it was starting to open at 180, when it should have been fully open by then.

A new thermostat is on the way.

There is certainly more to it than the number of cores and the size of the cores. You can run a 4 core radiator too, but what do you get? A total of 2 inches of tube. Same as a 2 core with 1 inch tubes and the two 1 inch cores will flow more coolant than the 4 cores at .5 inch each.

Fit the biggest radiator with the biggest, fewest cores you can get and use the thermostat to set your minimum operating temperature. Build in some safety margin so a few years down the road you won’t need to buy another radiator when you increase the power.
Nothing wrong with 195 degree coolant...that's where it should be. Even hotter is no issue...ive driven many vehicles that ran 200 or hotter, all the time.
 
Nothing wrong with 195 degree coolant...that's where it should be. Even hotter is no issue...ive driven many vehicles that ran 200 or hotter, all the time.


If you want to clan up the exhaust a LITTLE then this stupid hot coolant temperatures are great. If you want to run some compression and make some horsepower 180 is IT and that’s too hot. 160 is the best for a street car that needs a heater. Plus it’s damned hard to get much below that on a street car.

It’s long past time to stop saying high coolant temps are good. They are not.
 
Nothing wrong with 195 degree coolant...that's where it should be. Even hotter is no issue...ive driven many vehicles that ran 200 or hotter, all the time.
Especially with the fuel we have nowadays.

I agree, look at my new Daytona gauge, and that’s normal.

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If you want to clan up the exhaust a LITTLE then this stupid hot coolant temperatures are great. If you want to run some compression and make some horsepower 180 is IT and that’s too hot. 160 is the best for a street car that needs a heater. Plus it’s damned hard to get much below that on a street car.

It’s long past time to stop saying high coolant temps are good. They are not.

160-180 temps are drag race, track only stuff. It's not peak efficiency, it's peak power for a VERY short period of time. It's not the best operating temperature for efficiency or longevity.
 
160-180 temps are drag race, track only stuff. It's not peak efficiency, it's peak power for a VERY short period of time. It's not the best operating temperature for efficiency or longevity.


Thats just not true. Have you ever done it? And used the appropriate compression ratio? If you ever do it you’ll wonder why you didn’t do it before.

It isn’t less efficient and it has ZERO affect on longevity if you do it correctly. I suspect you’ve never done it and you are speaking from conjecture and speculation.
 
Thats just not true. Have you ever done it? And used the appropriate compression ratio? If you ever do it you’ll wonder why you didn’t do it before.

It isn’t less efficient and it has ZERO affect on longevity if you do it correctly. I suspect you’ve never done it and you are speaking from conjecture and speculation.

What’s your deal? I didn’t disagree that drag racers tend to run and tune their cars to run 160-180 at the track. They do and it works. But it’s not reasonable or smart to continuously run a street car like that, especially at the low end of those temperatures.

And if you look at other motorsports, pretty much no one else runs their engines that cold. NASCAR runs their engine temps at 290*F, because air flow and drag is more important. NASCAR is clearly a special case, but so is drag racing.
The Fascinating Reason Why NASCAR Engines Run So Hot

And I can tell you that the 340 in my Duster, as it’s tuned, does in fact run much better at 190-200 than it does at 160-180. I actually changed out the thermostat and reprogrammed my electric fan controller to raise the engine operating temperature to keep it between 190-200, previous to that I had been keeping it at 180. And if you go back at my build thread and look at why I ditched my mechanical fan and went electric in the first place it was because the car was running cold, and it wasn’t running as well as it did when it was hotter.

So yeah, I’ve tried it. I’m not gonna say that’s best for everyone or every engine, but 160-180 is a drag race trick, and it doesn’t carry over to the street or many other motorsports.
 
What’s your deal? I didn’t disagree that drag racers tend to run and tune their cars to run 160-180 at the track. They do and it works. But it’s not reasonable or smart to continuously run a street car like that, especially at the low end of those temperatures.

And if you look at other motorsports, pretty much no one else runs their engines that cold. NASCAR runs their engine temps at 290*F, because air flow and drag is more important. NASCAR is clearly a special case, but so is drag racing.
The Fascinating Reason Why NASCAR Engines Run So Hot

And I can tell you that the 340 in my Duster, as it’s tuned, does in fact run much better at 190-200 than it does at 160-180. I actually changed out the thermostat and reprogrammed my electric fan controller to raise the engine operating temperature to keep it between 190-200, previous to that I had been keeping it at 180. And if you go back at my build thread and look at why I ditched my mechanical fan and went electric in the first place it was because the car was running cold, and it wasn’t running as well as it did when it was hotter.

So yeah, I’ve tried it. I’m not gonna say that’s best for everyone or every engine, but 160-180 is a drag race trick, and it doesn’t carry over to the street or many other motorsports.

It’s not a “trick” drag race or otherwise. It’s simple physics. You have to tune for it. It’s not hard.

Just because I’m curious how much compression do you have and what carb do you run? Cold air intake or heated?
 
Radiator showed up today, looks great, got it mocked up in the car, needs a little adjustment here and there but not too bad, one thing i wanted to ask is how much clearance should be between the fan clutch and radiator core? Right now without the radiator being tightened to the core support i have roughly 7/16” between the fan clutch and core, im thinking when its tightened up it might open up to 1/2” of clearance, is this enough?
 
What’s your deal? I didn’t disagree that drag racers tend to run and tune their cars to run 160-180 at the track. They do and it works. But it’s not reasonable or smart to continuously run a street car like that, especially at the low end of those temperatures.

And if you look at other motorsports, pretty much no one else runs their engines that cold. NASCAR runs their engine temps at 290*F, because air flow and drag is more important. NASCAR is clearly a special case, but so is drag racing.
The Fascinating Reason Why NASCAR Engines Run So Hot

And I can tell you that the 340 in my Duster, as it’s tuned, does in fact run much better at 190-200 than it does at 160-180. I actually changed out the thermostat and reprogrammed my electric fan controller to raise the engine operating temperature to keep it between 190-200, previous to that I had been keeping it at 180. And if you go back at my build thread and look at why I ditched my mechanical fan and went electric in the first place it was because the car was running cold, and it wasn’t running as well as it did when it was hotter.

So yeah, I’ve tried it. I’m not gonna say that’s best for everyone or every engine, but 160-180 is a drag race trick, and it doesn’t carry over to the street or many other motorsports.

I forgot to mention I read this link, and if you read it correctly they make LESS power with coolant temperatures as high as 280-290 degrees. LESS power. Plus it’s harder on parts. Plus they run 100 PSI on the system.

They do it for aerodynamic reasons, not to make more power.
 
Radiator showed up today, looks great, got it mocked up in the car, needs a little adjustment here and there but not too bad, one thing i wanted to ask is how much clearance should be between the fan clutch and radiator core? Right now without the radiator being tightened to the core support i have roughly 7/16” between the fan clutch and core, im thinking when its tightened up it might open up to 1/2” of clearance, is this enough?

1/2” should be fine, that’s about the minimum you’d want but it’ll work. Might want to make sure your engine and transmission mounts are in good shape as you won’t want a lot of movement there.

I forgot to mention I read this link, and if you read it correctly they make LESS power with coolant temperatures as high as 280-290 degrees. LESS power. Plus it’s harder on parts. Plus they run 100 PSI on the system.

They do it for aerodynamic reasons, not to make more power.

Yeah, I said right up front it was for aerodynamic reasons, check my post - “air flow and drag”.

My point is that it’s stupid to tune your street car based on what a race car does. Pro-stockers try to run 100-120* at the start of a run. NASCAR runs 300*. Both are detrimental for the life of the engine and highly specialized to that type of racing and class rules. 180*-200* is perfectly acceptable for a street car, even 210* wouldn’t bother me a bit as long as it could maintain it. 160* is basically the minimum operating temp to prevent valve train wear and quite frankly isn’t realistic for a real street car in real world situations.
 
1/2” should be fine, that’s about the minimum you’d want but it’ll work. Might want to make sure your engine and transmission mounts are in good shape as you won’t want a lot of movement there.



Yeah, I said right up front it was for aerodynamic reasons, check my post - “air flow and drag”.

My point is that it’s stupid to tune your street car based on what a race car does. Pro-stockers try to run 100-120* at the start of a run. NASCAR runs 300*. Both are detrimental for the life of the engine and highly specialized to that type of racing and class rules. 180*-200* is perfectly acceptable for a street car, even 210* wouldn’t bother me a bit as long as it could maintain it. 160* is basically the minimum operating temp to prevent valve train wear and quite frankly isn’t realistic for a real street car in real world situations.



yeah its probably close to 7/16” motor and trans mounts are good plus i have a torque strap. I shaved down the fins by about 1/8” to get me at least 1/2”. Will it hurt anything for the fins to be 1/8 shorter? I only Did the center fins closest to the radiator, the outer portion of fins have plenty of room
 
Got the fan and clutch mounted up, looks like i will have right about 5/8” between the clutch and the core. Not sure if shaving the fins down slightly will have any ill affect on the clutch


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i have roughly 7/16” between the fan clutch and core, im thinking when its tightened up it might open up to 1/2” of clearance, is this enough?
Too close IMO. Others have said that 1/2" worked out OK for them. Solid mounts?
FWIW the MP............
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Got the radiator in its final resting place, had to open up the mounting holes some but its to be expected. waiting on a new lower hose and have to trim one little spot on the aluminum shroud and should be ready to fire it up


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