ok to start with i have a new waterpump, thermostat, 3 core all aluminum radiator, 16 in 1900 cfm fan, 12in 1300 cfm fan, head gaskets, and yes i have an air dam that i fabbed up.

now my problem is on my 86 bird with the original 305 my temp gets to 180 ( thermostat is a 180) in about 15 min on a warm day and then creeps up to 230 240 in another 15 to 20 min does not matter sitting or driving

i just dont know what else to do. i need help!!

my mods are

holley 650 4bbl
edelbrock performer intake
edelbrock performer plus camshaft with matching valve springs and lifters
comp cams aluminum retrofit 1.6 roller rockers
not original heads, cast iron 1.94 int 1.5005 exh 58 cc
and of coarse the rad and fans

 

What temp thermostat ?
At what temp are your fans coming on ?
Ware are the fans mounted ?

If ones a pusher and ones a puller or even if they are on the same side is the fan rotation correct? Look closely at the fan blades to determine the proper rotation. Once there on have someone kill power to the fans watching closely with a bright light. If there pullers than make sure they are pulling.


If a fan is supposed to be pulling but is actually pushing it will not push all of the air through the fins of the radiator. A large percentage of the air is kicked back. It will give the impression its pulling. As I'm sure you already know the fan wires can be connected either way. One way pulls and the other pushes. The polarity gets mixed up. You can't mount the fan and test it by sticking your hand down there to feel if the airs blowing the right direction. As mentioned above air that does not get pushed through blowsback. .Its easiest to see the blades slowing down rather than on startup.

This may sound trivial but can easily be eliminated as a suspect.

I know this first hand. I have installed two thermostatically controlled,adjustable switches and had to go through this procedure.


Also
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Thanks

 

Tkanks for the reply

I filled that out not sure of my gears yet

stat is a 180 fans kick on at 190 off at 180

ill triple check the fans on my lunch break

they are mounted on the radiator both as pullers

 

Update

Both fans are moving the correct direction as pullers

brought home the thermo gun from work and letiing the car warm up now

 

Ok temp gauge is at 225 ish , thermo gut shows 210 at tstat, 205 at upper rad hose on the fins, 200 by lower rad hose on fins, 197 on water pump bottom, 207 on top of the pump, 207 on front block freeze plug, and 227 on left head by the sensor

 

Is the overflow tank operating normally ?Cold line when cold and hot line when hot ?
Could the bottom hose be collapsing on you ?

 

Bottom hose is not collapsing but it has a bubble in it now I assume from the heat so im replacing it and yes hot line and cold line changes on the tank

im starting to think somethin in the block itself is plugged up. Its the only thing left unchecked......

I think im just goin to pull the engine and build a 350 and drop it in.......

 

So frustrating. ... I was gonna tty to stay "numbers matching"

 

I did just try a different radiator cap that I had and no change

 

Looking at these temps and the very minimal differences ( not including surface temp on head as radiant heat from exhaust could account for that minimal difference ), seems like your coolant is barely moving & radiator isn't hardly removing any temp at all. Sure there might not be some restriction in the radiator ( I know it's new but packing stuff? ) Also, I have had vehicles come in that had our new radiator installed before and the customer had changed the water pump & thermostat afterwards but used too much RTV and the stuff came loose and plugged up 60% of the new radiator with little pieces of the RTV. Unusual that it's running that hot and not overfilling the overflow reservoir. Can you run it long enough to see if it fills the reservoir and then begins to put a constant stream or intermittent but regular interval stream of air bubbles ( head gasket or head leak would overpower the radiator cap with combustion gases after it pushes enough coolant out). Having the whole block plugged up to the point that it wouldn't move water would be unusual. Was the old coolant really rusty and brown, like real bad???? One last thing, check your pump part # and make sure it coincides with your belt set up. I believe grooved pump pulley or V belt would be clockwise pump and smooth pump pulley would be counter clockwise. Would still move some water but not nearly enough. Parts guys screw up a lot at discount stores from time to time.

 

If you're not boiling over, then you're not overheating. With the readings you got, with the minimal difference between them and yet the gauge reads 225*, I'd say your gauge is simply off, reading on average 25* hotter than what it really is and that you're running fine.

 

Go buy a STOCK Replacement Radiator.
Had the same issues.

 

No rtv silicone used and some more in site the car sat for 8 years before I got it ans was park ed for overheating
coolant is spotless

 

Also overheating to me is running hotter than what the thermostat will allow

 

Pour in some Marvel mystery oil. Let it circulate in the block for a bit. I've heard of some GM blocks that didn't have all the sand removed from them, probably a 2:55 pm block on a friday. Then over the years all that sediment builds up and blocks the water jackets at the base of number 7 and 8 cylinders.

After the marvel has been in there for a week or so, flush the block. Then try again. This can be what your problem is and can take a bit to fix.

You can call around and see if a local shop has a power flush system. My buddy has one at his shop. He had to do this to my dexcool filled 01 Silverado to get the crud out of it. You might even have to remove the water jacket plugs at the base of the cylinders. Then jam a piece of wire in there to get the crud out.

Worst case scenario, you will have to remove the intake and heads. Then clean all the water jackets out manually with block brushes

I hope this isn't your problem but it happens when a car sits and nobody flushes the cooling system.

 

Well, the t-stat only controls minimum temps and was never designed to control maximums as you are finding out. The 220f or so would not be as big of a concern but the 240 would be to me. The other concern is that infrared temp guns usually tend to read a bit colder than actual temps. Does your car have a heater return line just below the filler neck so you can turn on the heater ( if you still have a valve ) and watch the coolant coming in to the radiator? You might need to lower the coolant level a bit to watch this moving. This might at least give you some idea of it the pump is pumping well. If you can see good coolant movement at that point, I would remove the thermostat completely and see how the car behaves.

 

just to let everyone know..... i pulled the engine, freeze plugs and heads removed and found a "dam" of sediment and rust on the right bank blocking off cooland flow to # 6 and 8 cylinders

 

^^^^Thats EXACTLY What I was talking about!!!^^^^