So I put a new radiator in, Frostbite Aluminum Radiator 4-Row 67/69 V8 ,Fan/Shroud Package FB509H, to fit it, a new water pump,FlowKooler 1649 - Hi-Flow Mechanical Water Pumps, still heats up, I set my advance to 6*,still heats up, cannot even drive it, going down hill, still does not seem to cool down? this is a rebuilt 400, runs pump gas, no high compression engine, was running cooler with my old radiator, a brass 3 row?
Did you install the water pump divider plate and clearance it properly ? 6 degrees of initial timing is hardly enough for a vehicle to get out of its own way and idle decently. 15-18 degrees would be much better. Does this engine have a thermostat ?
I am trying to fix the heating issue, Pontiacs have a problem with heating up with to much advance, yes it has a 180* thermostat, yes the plate is clearanced
So everything was great, that is to say not overheating. Did this engine ever run and not overheat?
Then you changed a couple things and now things are bad. The radiator might be a problem but they are a very simple concept. So my guess is something ain't right with that water pump or the thermostat isn't opening.
Is the pump working? That is to say... pumping fluid. Is the thermostat opening?
I'm wondering why you messed with the timing at all? As mentioned 6 deg is way off.
does it go over 220 while driving down the road with air moving thru the radiator? you can use an inferred heat gun to check the inlet and outlet temperature of the radiator. an aluminum radiator should drop 220 degrees coolant down to at least 180 no problem while just sitting there with an engine driven fan.
I have heard of similar things happening because of air bubbles being trapped in the system. I mean, it sounds like you are doing all the other things right with airflow, pump, and the radiator. It's all heat in, heat transfer, heat out. We'll keep helping with suggestions until we get it.
John
To err is human. To really foul things up takes a computer.
Well if everything worked well before the rad swap and overheats after the swap, perhaps it's the new rad.
I agree with the others' comments about the timing. With the timing set so low the air fuel charge may be still burning as it heads out the exhaust port. That heats up the surrounding metal and the coolant. Maybe try 16-18 initial and try connecting the vacuum advance can to manifold vacuum port rather than the stepped port.
I once solved a friend's hot idle problem by simply changing the connection of the vacuum can from stepped to manifold. He had initial at 12 but the extra 20 degrees of vacuum advance cooled the idle temp.
Not to say it isn't one of the other suggestions, air can get trapped in the cooling system which would cause hotter coolant as well as thermostat etc.