Had a old stock plastic overflow tank w OEM cap. 400 horse 383 with champion 3 core and 1 single elec fan. Car would sit at 180 degrees and not budge, fan on rocker switch run constantly.

All being the same installed the canton tank and it will run 180 if I baby it. Jump on the throttle and screw around its 195 to 220 depending how far you take things. It does recover back to 180 when drive it calmly.

I spoke with Canton as I had heard rumors about the venting of there caps. They assured me it was vented. If it is it's a **** poor design. There's a rubber gasket under the cap and a ring with a tiny "vent" slot cut in it. They sent me another one it's the same design.

I drilled a 3/16 hole through the center of one of the caps and saw no change.

The tank looks awesome with how I have my engine bay I dont want to go back to a stocker, I'm shocked about what this thing has done to coolant temps.

Thoughts and advice very welcomed.

 

The overflow tank has virtually nothing to do with your operating temps. The only way it could affect the system is if, after a normal heat cycle, it did not allow the coolant to be sucked back into the radiator. It's just a non-pressurized overflow bottle. It has ZERO impact on the operation of the cooling system. A beer can would work just as well. They don't need much vent. A 1/16" hole would do.

 

I agree with you however I dont understand it. Nothing has changed. Air dam is same, motor is the same GM crate less than 2kmi, stat is the same. Timing was not changed, neither carb adjusted.

 

Have you tried swapping back to the stock tank (or a beer can) to see?

You clearly have correlation. Now you need to prove causation.

I suspect you may find this is an unfortunate coincidence. 2k miles is pretty low. Sounds like many things got "touched" recently. I would suggest a cooling system pressure/leakdown test.

GD

 

A beer can? What I'm confused.....

Set down you warrior keyboard bud.

I replaced the rubber line, it may have been fuel line spec as no markings on it, going to try a different hose first, possibly this one collapsing under heat.

Keep your beer can full!!

 

To wit:

https://www.jalopyjournal.com/forum/...-tanks.302437/

.....Shlitz Tall Boy. Hose clamps...... drink the beer and use the EMPTY can. Don't put beer in the cooling system. No good drunk will come of that.

Someone please step in here and help me out. I must not be breaking this down to the lowest common denominator for him.

Remember - long, firm strokes. Slight twist at the top.

GD

 

I don't see the hose collapsing.... the radiator is going to be pushing. Fill the radiator and drive it. Does it overheat on the FIRST drive? Before it cools down and is expected to dutifully return the coolant on request..... if it does then the overflow isn't the problem.

 

Thanks for the jalopy link reference. I Iiked hotrodders.com yrs ago but not so much now (doc passed away).

I am going to try the old hose first, thanks for your input.

I will not be suddenly checking my cylinder pressures or performing a leak down test.

 

No. Cooling system pressure/leak down test. That's when you manually pump up the cooling system with a pressure gauge and look for leaks and watch it bleed down to see how quickly it loses pressure, etc. Has nothing to do with the cylinders (unless coolant is going into them)

like this:

 

You assumed an "unfortunate coincidence" "lots of changes made" and "a few pressure checks"

Thanks for your opinion

 

No assumptions. Absolutely reasonable suppositions based on available evidence.

I do this for a (very good) living. Every. Day.

What's your explanation? You came here for help did you not? I don't see anyone else offering..... why not perform a cooling system pressure test? What's the harm in it? You test to rule out possibilities. That's what tests are for ya know.

Sounds like you have confirmation bias. You already believe it's the fault of the overflow tank yet you have no evidence other than the circumstantial evidence that it happened after installing it. That's not enough.

GD

 

Explain to the folks at home what suppositions means

Swapped the line back over let you know.

 

It can't be a hypothesis because of the uncertainty of the internet. I'm not there. Which introduces unavoidable uncertainties. An assumption would require me to be in complete agreement with it. Which is impossible due to the above stated. So the best I can do is a supposition. I am still open to other arguments of course.

I'm not seeing a compelling line of reasoning to suspect the hose. But sure..... it's a cheap enough thing to rule out. I wouldn't take the bet though.

Looks nice. But invest in some ear clamp pliers and an assortment. Really cleans things up to eliminate all those worm clamps. And they are terrible for even clamping force on small diameter stuff like your overflow hose. Get the tongue and groove ear clamps that can't pinch the hose.

GD

 

Let me guess your an engineer, not a mechanic. You got me thinking a little more


Thanks for your help bud.

 

Of sorts. Actually was a software engineer by education. I own a performance/repair shop for about 10 years now. Besides my main focus on engine buiding my software background gives me a competitive edge when tuning on our 2000 HP AWD DynoJet.

But yeah I tend to be analytical with diagnostics.

Good luck. I hope the hose does the job.

 

Go to bed

 

Issue resolved, the hose must of been collapsing

 

Hhhmmm that's odd. I wonder at what the mechanism behind these effects is. There really shouldn't be a significant exchange of fluid between the tank and radiator once it's at operating temp. Possibly the system would be low if the hose didn't allow the coolant to return once it goes through a cool-down cycle. This should have presented as an ever-increasing level in the tank rather than a rise when hot and a fall when cold.