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hey guys, i have a problem with my 63 sagon with l-6. it wants to over heat at highway speed, 70mph. i cooked the thing a couple of weeks ago on my way to lebonon to a car show. it does fine at idle and low speed but at highway speed it tends to overheat. i talked to a guy at bowling green this weekend and he has a 63 with a v-8 and said he had the same problem with his. he put on a new aluminum radiator and still has problems at 70 mph and up. anyone have any ideas. i would hate to put my new engine in the thing and cook it too. it is a l-6 with a 390cfm offy intake, split manifold, and stock 250. thanks for any help. jim
 

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hey guys, i have a problem with my 63 sagon with l-6. it wants to over heat at highway speed, 70mph. i cooked the thing a couple of weeks ago on my way to lebonon to a car show. it does fine at idle and low speed but at highway speed it tends to overheat. i talked to a guy at bowling green this weekend and he has a 63 with a v-8 and said he had the same problem with his. he put on a new aluminum radiator and still has problems at 70 mph and up. anyone have any ideas. i would hate to put my new engine in the thing and cook it too. it is a l-6 with a 390cfm offy intake, split manifold, and stock 250. thanks for any help. jim
I just bought a 62 wagon last weekend and drove it 440 mile to get it home, 70mph and 160* all the way home. I don't know the secret, my wagon is all stock with a 160* thermostat (194ci with a glide)
 

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Sounds like a water flow issue. check for plugged radiator, pump cavitation, or a bad impeller.
 

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well the radiator is stock but i had it rodded out and leak checked. the water pump is new, new hoses and i am running a 180 stat. is that too hot? timing and all were good. guy i talked to this weekend said something about putting a washer in some where. he lost me right away. thanks
 

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hey i just thought of something, what about the fan. the car does not have a shroud and has the stock 4 blade fan. could that be it?
 

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At highway speed the fan is not needed to cool the engine. Stock engine and cooling system shouldn't have any problems even without a shroud. Typically(but not always) a heating problem at highway speeds is an idicator of an undersized rad or insufficient water flow through the rad/engine. Stock fan should be OK. Try another thermostat or test the one that was recently put in. Put it in a metal container with water and bring it to a boil. The thermostat should be all the way open before the water boils. Use an old pot(wife approved) and a barbeque etc... I always drill a 3/16" hole in my thermostats(the outside area of the opening part) as a bypass to moderate the coolant flow and if the thermostat sticks then at least something will get through.
 

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i was having the same problem with my 250. it has a offy intake and a edelbrock 600cfm carb. i changed out the thermostat to a 160 and put water wetter in it and it never goes over 160 now. drove 2 hours straight after the BBQ and 70 all the way home. no problems at all. oh and no shroud on mine
 

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If an automatic transmission has cooling lines to the radiator, the transmission could be adding too much heat also. How is the condition of the transmission. Color and smell of the Transmission fluid good? If dark and burnt smelling, transmission could be slipping.

Check the simple things
The total advance at higher RPMs
Fan belt good? Properly tightened?
Is it loosing fluid during the drive?
Radiator cap leaking, correct pressure rating?
 

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Could also be a compression leak into the cooling system (bad headgasket or crack in block or head). This can overpressurize the cooling system, causing it to loose water, then it overheats. Do you have a guage? What temp are you seeing? Or is it just blowing out the cap then the idiot lite comes on?
 

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Discussion Starter #15
thanks. i never heard of the stuff. the guy at the parts store uses it in his bb vette and he swears by it. thanks again. jjim
 

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I use Water-Wetter and straight water, no antifreeze. No heating problems with a .040 over 400sbc.
 

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I "HAD" the same problem with my 62 with a 383 TPI. I tried everything, 3 diffrent water pumps, a stack of diffrent thermostats, new hoses, alum summit rad, etc, etc, etc. and still had the same issue. I finally went with a good rad, dual elect fans and shroud best money I spent.

http://cgi.ebay.com/ebaymotors/NEW-Aluminum-Radiator-Nova-61-62-63-64-65-66-67-Fans_W0QQitemZ280408605395QQihZ018QQcategoryZ33602QQssPageNameZWDVWQQrdZ1QQcmdZViewItem





hey guys, i have a problem with my 63 sagon with l-6. it wants to over heat at highway speed, 70mph. i cooked the thing a couple of weeks ago on my way to lebonon to a car show. it does fine at idle and low speed but at highway speed it tends to overheat. i talked to a guy at bowling green this weekend and he has a 63 with a v-8 and said he had the same problem with his. he put on a new aluminum radiator and still has problems at 70 mph and up. anyone have any ideas. i would hate to put my new engine in the thing and cook it too. it is a l-6 with a 390cfm offy intake, split manifold, and stock 250. thanks for any help. jim
 
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