Does any body know what proper lbs. pressure radiator cap goes on a 235 engine. I just want to know so i dont blow out my heater core when i hook it up for the first time thanks for the info.
Radiator cap 4 pounds I have been using a 4 pound cap on my 235 radiatoron my 54 for the past 6 years. Works just fine. Jim
I have been running mine at 0 psig for the very same reason - I burst a heater core once (a while back) and I have no overheat/boil over issues at 0 psig. Those donut cores are hard to come by (the ones that don't leak that is). GLTA
Cooling System Pressure Only 3 # maximum as pressure doesn't help cooling one bit . The stock radiator in an AD is sufficient to cool off a Caddilac 500 C.I. engine with tranny cooler and AC , full power etc. , in 125° F desert heat so if your old 6 banger or SBC engine is overheating , look elsewhere for the problem , the radiator is prolly clogged or the timing is off , etc. . Remember : Citric Acid Cleaning works wonders and doesn't hurt the radiator .
Newer cooling systems were designed to work more efficiently under more pressure. The old AD is not effected by pressure.
Cooling Systems That's not quite correct ~ Modern engines are designed to run at higher operating temperatures (increases efficiency etc.) and so need more coolant pressure as each pound of pressure raises the boiling point oif water by 3° F . My '49 shop truck runs a '57 235 and I have a 185¯ F thermostat in it so I get better power and fuel milage out of it plus of course , NO sludge buildup in my old tech engine..... I know most are worried about running an old engine too hot but as long as no boilover , it's actually better for the engine to run as close to boiling temperature as possible .
