overheating 350

[chevycowboy]

Ok so i have a 350 that is overheating and i dont know why?
Last year and most of maylong this year its been running great i rebuilt it 4 years ago but have not put a lot of miles on it...  two years ago i thought it would be fun to blow up a lifter and ALL the wiring.....   so then after some rebuilding i got it working and took it out 4 or 5 times...    it sat most of the winter untill maylong where by the week befor i took it out to see if there was any bugs bfore i went hard for the weekend.  it ran great the temp. was around 190 to 200...   on may long a good one and ahalf good hard days untill the temp started to spike at 210 to 230 but it sounded like i had broke my water pump.. so we spent most of the day towing it out of the bush as so not to over heat it....     when i got home i changed the water pump cleaned the engien and rad and put on a new rad cap....   coolint is at 50/50 and i have also done a pressure test on it and it held fine...   oil is still same level as it was when i left and clean...   there is all so no theromstate in it...    but with in ten miunts of driving around the block it hits 210 to 230 why is it overheating?

[jandh]

Not sure if the pressure test would catch this or not, but do you have a plugged rad?  or even a large amount of air in it.

Test it and see how your coolant is flowing in and out of the rad

[Fredduck]

Ok so i have a 350 that is overheating and i dont know why?
Last year and most of maylong this year its been running great i rebuilt it 4 years ago but have not put a lot of miles on it...  two years ago i thought it would be fun to blow up a lifter and ALL the wiring.....   so then after some rebuilding i got it working and took it out 4 or 5 times...    it sat most of the winter untill maylong where by the week befor i took it out to see if there was any bugs bfore i went hard for the weekend.  it ran great the temp. was around 190 to 200...   on may long a good one and ahalf good hard days untill the temp started to spike at 210 to 230 but it sounded like i had broke my water pump.. so we spent most of the day towing it out of the bush as so not to over heat it....     when i got home i changed the water pump cleaned the engien and rad and put on a new rad cap....   coolint is at 50/50 and i have also done a pressure test on it and it held fine...   oil is still same level as it was when i left and clean...   there is all so no theromstate in it...    but with in ten miunts of driving around the block it hits 210 to 230 why is it overheating?

Put the thermostat back in it. The thermostat slows the water flow in the rad so it will cool. put in a 180.

[chevycowboy]

ok so the thermostat was out befor it was over heating / i havent had one for a year or two.....   and how can i test the rad to see if its pluged, there is good flow out the top???   also talking to some ppl i found out that i might have a bad head gasket, but the engein still as power when its not trying to overheat...

[XJwrencher]

Are you running a fan clutch?if so is it seized?

[chevycowboy]

yea its a fan clutch it has 7 blads but i dont know what size it is when i rev the engein it dose blow driy dirt off the engein so it is spining but i want to change it to a flex fan...  good call yes/no???

[Crunch]

when a viscous fan clutch cuts in you should be able to hear the air flow difference-it will be louder when your
engine is running higher than idle
also if you have a head gasket blown most of the time your cooling system will pressure up and blow
coolant out the rad befoe you over heat-hope this helps