Overheating with v8 rad

Srt4cooled bird

Registered User
So I didn't have the. $ for a griffin rad.so I found and purchased a all alluminum v8 rad for a tbird.to my dismay it doesn't have a rad cap.no spot for it just the overflow hose nipple.i think I need a cap bc the overflow fills up and overflows and thus cooling down sucks in air.options??inline rad cap spliced to upper hose ?weld in a cap in top of rad?i can't use a v8 overflow resivoir bc the hoses are bigger and there's two hoses instead of just the tiny one for the overflow tank.options/opinions??
 
Thanks

Do u think pressure is the issue?it needs the cap?i can get one at the junkyard too from a Durango too I think but that's the part I was thinking.thanks for the input
 
What issue? If you can't bleed and pressurize/regulate a cooling system correctly, it will overheat...is that what you mean? You've already tried plumbing it without a cap and vent?

Is that V8 radiator crossflow or vertical like the SC? Does it hold more coolant than the SC radiator?

Get that adapter, then get a #16 cap that fits, then plumb the stock overflow tank. Be sure to use the cooling system bleed standoff to clear air pockets.
 
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Rad

My issue that it over flows when it heats up like the tank isn't big enuff but I think it's bc it does dnt get pressure from the cap.i don't know exactly what the cooling system need to op correctly.but I'm sure it need a cap.its cross flow I believe the tanks are on the side rather than top and bottom like a stock sc rad.the rad I installed is for a v8 tbird that has the rad cap on the expansion tank
 
My issue that it over flows when it heats up like the tank isn't big enuff but I think it's bc it does dnt get pressure from the cap.i don't know exactly what the cooling system need to op correctly.but I'm sure it need a cap.its cross flow

I think that crossflow holds less coolant.

You can't just add a radiator (with no cap) and hoses and close it up.

But yeah, it needs to be properly configured and bled. Until you do that, you won't know if it helps. If you don't completely understand how all this works, I think you may have better luck sticking with a stock system :)
 
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Good luck....I'd be interested if you can make it work like you want, so if you can follow up with details/results it would be neat, thanks.
 
Rad

Good luck....I'd be interested if you can make it work like you want, so if you can follow up with details/results it would be neat, thanks.

Yea I'll keep u posted the trans went out and I'm waiting on my buddy to put another one in in and figured I'd fix my rad issue.just a pain for the most part that rad works great but stopping in traffic the temps climb and the fan kicks on but it's not enuff.pretty sure bc it has no cap.so that was my fault
 
If you now have a cap-less radiator, you need a reservoir built to hold pressure or some way to add a cap, like KMT posted. Otherwise, it simply won't work. Overflow tanks (like the factory SC), are just there to catch coolant as it heats up and store it until it cools down, at which point, the radiator cap will allow the coolant to get pulled back into the radiator. Newer systems without a cap/filler neck on the radiator use reservoirs that will be pressurized when the coolant heats up and expands.


I would guess that once you have a system that is operating properly, you'll be okay, but good luck!
 
Thanks

Yes I agree thanks for the help.i know a good bit a about cars but some areas I'm fuzzy on the little details of how it exactly works and y.i couldn't justify the griffin price and I had my stock rad fixed twice and got tired of fixing it which is y I looked for an alternative.i found like ten rads that were stock replacements ordered and paid for them and a week later each company told me they didn't have them.y list it on ur website that u carry it,also call them to confirm they have it,they say yes then later tell me they can't get it.~~~~
 
Rad

Ok guys I got the inline cap from a dodge Durango at the junk yard 5$ and it has the cap.cap is metal and the tube etc is plastic looks like it will work.i get my torque converter mon so when I get the trans in next week I'll let u know how this works.unsure what to do about the overflow nipple on the rad tho.may cap it off.since the Durango has one at the cap.cant post the pic mayb later
 
Yes I agree thanks for the help.i know a good bit a about cars but some areas I'm fuzzy on the little details of how it exactly works and y.i couldn't justify the griffin price and I had my stock rad fixed twice and got tired of fixing it which is y I looked for an alternative.i found like ten rads that were stock replacements ordered and paid for them and a week later each company told me they didn't have them.y list it on ur website that u carry it,also call them to confirm they have it,they say yes then later tell me they can't get it.~~~~

For reference.

I have a griffin radiator in my car that was a universal setup off Summit. It was $195 shipped...I then took it too a fab shop and had them weld 2 inch wide flat stock on it for mounting 6 inches on each side. I then cut it down to mount in the stock locations...drilled holes and mounted it to the OE locations...Total invested was $215 and essentially I have the same radiator as the expensive $400-$500 units.

Wasn't a direct bolt in but for a little fab work it was worth it. At crusing speeds my car runs right at 180 per QH.

-Tim
 
For reference.

I have a griffin radiator in my car that was a universal setup off Summit. It was $195 shipped...I then took it too a fab shop and had them weld 2 inch wide flat stock on it for mounting 6 inches on each side. I then cut it down to mount in the stock locations...drilled holes and mounted it to the OE locations...Total invested was $215 and essentially I have the same radiator as the expensive $400-$500 units.

Wasn't a direct bolt in but for a little fab work it was worth it. At crusing speeds my car runs right at 180 per QH.

-Tim

do you have some pics....i'm kinda visually oriented....not a very good imagination.
 
do you have some pics....i'm kinda visually oriented....not a very good imagination.

Here's a small time line of the work that was done. The radiator used was a universal Griffin Radiator that had no mounting on it what so ever. I contacted a local metal shop and asked if they could complete what I was looking for...that said sure come on down. I had them weld 12 inches total from all 4 directions...I then cut it to fit once I got home (there was no complex blueprint ideas in the design) I centered the unit given I have no facotry IC, bolted the top portion in the factory holes. The bottom sits on the radiator frame area.

If I had the Factory IC this would still work as I have plenty of room on either side. I will try to find the part # of the radiator used but I purchased it off summitracings ebay page.



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Also with this - everything considered...Those with a front mount home made spend $400-$600 on average...and then another $200+/- for a Better Radiator...still hunderds less than the orginal MP IC kits...however fabbing it yourself is always less than something already made to install.

-Tim
 
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FYI, the reason the cap matters is because pressurized fluid is more dense, has a higher specific heat capacity, and therefore a higher boiling point. The higher boiling point allows the engine to run hotter without boiling the coolant, which would cause local hot spots and problems in pumping. Without the pressure, you get those problems, which is bad. To avoid them, you have to run the engine much cooler. That hurts the thermal efficiency of the engine, costs power, and makes it wear out faster. Plus the local hot spots still won't be cured.

So pressure in the cooling system is a good thing!
 
Ahah

Now that's the little detail I needed.thats what I didn't know that makes perfect sense.i knew the how it works just not y It needed to be.thanks for that info.and as for the year Durango I have no idea I looked at 5 and none had a rad.so I just found one that had a rad and the inline cap.
 
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