crossflow vs downflow radiators wich is best - Chevelle Tech
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post #1 of 3 (permalink) Old Jul 16th, 08, 6:18 PM Thread Starter
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Question crossflow vs downflow radiators wich is best

I have been told crossflow radiators cool better then downflow is this true? I have a BB chev. in a 65 ss, and this car comes equiped with a down flow originally.
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post #2 of 3 (permalink) Old Jul 16th, 08, 8:47 PM
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Re: crossflow vs downflow radiators wich is best

Either will cool well, but the crossflow has one distinct advantage. A crossflow radiator will allow more pressure at the radiator inlet before the cap vents because the cap is on the low pressure side of the radiator.

Cross flow radiators are superior to upright radiators because the radiator cap is positioned on the low pressure (suction) side of the system. This prevents the pressure created by a high-flow water pump from forcing coolant past the radiator cap at high RPM. As mentioned in the radiator cap section, an upright radiator should be equipped with radiator cap with the highest pressure rating recommended by the manufacturer. The system will still force coolant past the cap at sustained high RPM.

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post #3 of 3 (permalink) Old Jul 17th, 08, 4:27 AM
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Re: crossflow vs downflow radiators wich is best

that statement is very correct in regards to presure ...there is a myth about crossflows being superior to down flows as far as cooling .. all in all its about SQ inches of cooling surface .. as of 68 most rads went to crossflow as hood lines got shorter .. so no where to go but wider .. so more SQ inches = more cooling .. but you will see many truck rads still run down flows due to the area and hood lines being taller .. look under the hood of a
f-350 .

the vertical tubes of a down flow work well with heat convection .

just a note
64 to 67 Chevelle bb ..403 SQ inches of core .. change to a cross flow conversion 374 SQ inches of core area ... a loss of 29 sq inchs of cooling core surface area .

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