1961 Chevrolet Truck overheating

Tiny
BRIAN H BAUMANN
  • MEMBER
  • 1961 CHEVROLET TRUCK
  • 5.3L
  • V8
  • RWD
  • AUTOMATIC
  • 40,000 MILES
I have a 1939 chevy pick up street rod with a 350 motor and a 350 turbo trans on a s-10 chassis. It has an aftermarket ac unit in it. The condenser is mounted in front of the radiator along with an electric fan. The truck has an alunium radiator, high flow pump, 160 degree stat and the electric fan . The truck runs hot after only 25 mins ( almost on H on the gauge, about 220 plus ) there is no white smoke from the tail pipe, no water in the oil, no loss of anti freeze so i'm thinking this could be an air flow issue. The higher the rpms the faster it overheats. I m thinking the rad is not getting any air flow with the fan in front of the condenser. Should there also be on the engine side and should it be a push or pull unit. Whats your thought .
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Monday, July 7th, 2014 AT 7:25 AM

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Tiny
HMAC300
  • EXPERT
First when itgets hot with engine off place hand on several spots on radiator if you feel any cold spots the rad is not good it should be the same temp all over. Then check for blockages between condenser and radiator. The fan in front may not be big enough meaning itdoesn't flow enough air. Also have it pressure tested for a head gasket leak. If you decide to mount another fan get a pull type mounted on inside of rad if you have room. Finally what is your compression ratio if you know it. A higher compression motor will run hotterdue to compression causing heat. Also a lot of factory cars just normal ones will run at 210 normally. You can also add some of the additive to run the car cooler in the antifreeze, it works. And if you aren't running antifreeze do so with a 50/50 mix
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Monday, July 7th, 2014 AT 8:43 AM
Tiny
BRIAN H BAUMANN
  • MEMBER
Thank you, ill give it a try
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Monday, July 7th, 2014 AT 8:53 AM
Tiny
CJ MEDEVAC II
  • MEMBER
DIFFERENT GUY - OTHER THOUGHTS YOU MIGHT ADD TO THE POSSIBILITIES

JUST TO INTERJECT SOME STUFF!

NOW DAYS YOUR RADIATOR HOSES SELDOM HAVE A ANTI-COLLAPSE SPRING IN 'EM, I ALWAYS SWAP THE OLD SPRING TO MY NEW HOSE, IF THEY DON'T.

COULD YOU JUST BE SO "WOUND UP" IN IT, ON TOP, THAT MAYBE YOU ARE MISSING INTERMITTENT HOSE COLLAPSE OF ONE OF THE HOSES? 'SPECIALLY AT HIGHER RPMS?

THIS MAY OR MAY NOT HELP BELOW

I'VE HAD PROBLEMS (IN THE PAST) WITH MY THERMOSTAT ALLOWING THE WATER TO GET A BIT HOTTER THAN IT SHOULD ON THE MECHANICAL TEMP GAUGE, LIKE GETTING UP TO CLOSE TO 200 DEGREES OR MORE BEFORE IT WOULD SUDDENLY OPEN AND BE NORMAL (180 DEGREES), A LOT OF THE TIME, IT WOULD REPETITIVELY DO THIS WHILE DRIVING AND SOMETIMES IT WOULD SETTLE AND STAY WHERE IT SHOULD. I TRIED MANY DIFFERENT THERMOSTAT BRANDS, EVEN THE EXPENSIVE "LIFETIME WARRANTY" JOBS THAT WERE AVAILABLE. NO DICE. THE WHOLE TIME, IT DID REMAIN IN THE "SAFE ZONE". HOWEVER, IT DID WORRY ME THAT IT MIGHT NOT DROP TO IT'S PROPER TEMP AND OVERHEAT SHOULD I QUIT PAYING CLOSE ATTENTION!

I DISCUSSED THIS WITH MANY PEOPLE, FINALLY I FOUND ANOTHER CJ GUY, WHO HAD THE SAME PROBLEM AND A SOLUTION!

I'M NO ENGINEER, AND HAVE NOT "FLOW TESTED" THIS IN A LABORATORY ENVIRONMENT. OR KNOW FOR SURE THAT THIS WOULD PROVIDE BETTER FLOW MORE VOLUME THRU IT. BUT IT DID FIX MY PROBLEM! I HAVE STUCK WITH IT EVER SINCE

A SUBARU THERMOSTAT (COMMON TO MANY SUBARUs), 56 MM, ON BOTTOM SAYS "STC"--IN THE PARTS STORE, IT'S THE ONE FOR MOST SUBARUS. YOU WILL RECOGNIZE IF IT'S RIGHT BY THE O.D AND MY PIC AT THE BOTTOM OF THIS

THIS IS A PERFECT FIT REPLACEMENT FOR MY OEM 258 THERMOSTAT

IF YOU LOOK AT THE PIC, REGULAR OLE JEEP STAT IS ON THE LEFT, WITH A SMALL CENTER TRAP DOOR, AND SUBARU IS ON THE RIGHT WITH THE BIG TRAP DOOR

THE OTHER JEEP GUYS' THEORY WAS, OPENING EITHER STAT REQUIRED THE SAME TEMPERATURE - THE BIG DOOR IS LESS LIKELY TO STICK/ WEDGE IN THE HOLE (DELAYED OPENING), AND WILL ALLOW MORE FLOW THRU THE STAT. MY GAUGE NOW STOPS AT 180 OR 195 (WHICHEVER I'M RUNNING), THIS HAS BEEN WORKING GREAT FOR ME, FOR YEARS! CORRECT THEORY OR NOT!

WORKS FOR MY 1946 WILLYS W/ L-134 TOO

TAKE IT OR LEAVE IT, JUST SOME THOUGHTS

THE MEDIC
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Monday, July 7th, 2014 AT 7:41 PM

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