Have a 74 J20, new aluminum radiator with 2 12" fans, new water pump, tried with a thermostat and with a restrictor plate in it and it still heats up to quick and gets over 200. Any ideas?
Air pockets?
Make sure ur fans are running the right way for that vehiclethey either gotta push through the radiator or pull put a dollar on radiator and u can tell witch way they are working reverse wires to change rotation and see if that helps
check radiator cap if its no good it wont pressurize the system and it will heat up faster
Brand new cap come with radiator, fans are pulling thru on outside and going in correct direction. Am thinking that block maybe clogged. Am going to try a back woods way to try and clean block. Running out of ideas. Also it does not have a stock fan on it.
heater core hooked up? bypass it if it is see what happens. Also double check for pressure, squeeze the hose when its warmed up, sometimes even new caps are bad.
Timing too far advanced?
Quote from: huntermrh on May 23, 2014, 10:32:37 PM
Brand new cap come with radiator, fans are pulling thru on outside and going in correct direction. Am thinking that block maybe clogged. Am going to try a back woods way to try and clean block. Running out of ideas. Also it does not have a stock fan on it.
Prestone makes some stuff to flush a engine if the coolant gels up it works for that pretty good can you look in the rad cap and see the coolant moving ???
Could be running lean too...that will make it heat up pretty quick
Are you using the proper antifreeze mix or straight water ?
Has the top end been apart recently?
It's the original 1974 360 2bbl. Has not been apart or timing messed with. Runs fine starts good. Still has points, does not have heater core, that would help cool. Have brand new antifreeze. Does not have water in oil, and is not losing water.
is the radiator down flow or cross flow? with a brand new down flow rad it could be the coolant is not staying long enough to cool down in the rad so it just keeps building heat. so what t stat are you running?
Trya real t stat. Not a restrictor plate
Put a radiator in the bed so you haVe 2 radiators cooling
Just take the hood off :D
what about the air flow too the radiator ? those trucks have a pretty small opening behind the grill and if you have the bottom of the engine closed/mud proofed the heat cant get out anyplace