Ok so i have a 86 t/a with a carbbed 350 in it out a 76 chevy pickup. My main concern is that it will idle all day and maintain 190° F, but as soon as u head down the road it over heats im talkin 240 quick, new thermostat new radiator newer hoses new water pump, does have air dam but the fan shroud is gone im just at a loss

 

Are your fans operating properly?

 

Yea i just have one fan in the center on the back of the radiator it runs fast and moves alot of air its turning the right way its got me puzzled

 

Just to be clear, the fan is blowing air towards the eng right?
Is the ignition timing set right?
Any bubbles in the coolant?
Is the lower radiator hose collapsing when the eng is rev'ed up?

 

Yes that is correct fan is blowing towards engine i filled the coolant with it running and waited till the t stat opened as far as the timing i never messed with it all i did was retarded the timing using the dist. Never messed with the timing chain though and i can rev it up and i dont see the hose collapsing

 

Retarded ign timing will make an eng run hot. Probably should verify it with a timing light.

In regards to the lower radiator hose, did you hold the rpm at abt 2500 RPM for like a min or was it just a short burst?

Is there a spring inside the lower rad hose? If so, you can skip this test.

 

I just did it in short bursts and there is no spring in the hose i might go get one though im in the process of building a 383 for this car but i dont wanna run into this with a new motor and its gonna be a while till i get it done so i will throw the timing light on it and i will get a spring and see if makes a difference

 

Well im pretty sure i found my problem the lower hose is sucking shut its a brand new hose so i bought a cap thinkin maybe the old one was venting all the time. I havent installed it but when i do i will post results

 

That's usually a sign of an old hose going bad. Probably just got a bad one from the store.

 

Well now if i can figure out why my car is missing it will be good to go new cap rotor plugs wires timing set at 10 deg and and a steady miss all yhe time on the gas or off probably a lobe wore off the cam

 

So i now have an all aluminum 3 row radiator 2 fans new hoses new t stat new pump and still overheating but only when im driving down the road at above 35 mph. Im about to unhook a fuel line and set it on fire!

 

Assuming your lower radiator hose isn't collapsing any more, verify the air dam is in good shape.
In regards to the missing, pull/inspect the plugs.
A compression test would be a good idea too.

 

Same question as ZZ28ZZ. Do you have the air dam installed? Is it in good shape? Fans are only for cooling below 35mph.

The airdam creates a low pressure area behind the radiator that pulls air over and across the radiator when you're at speed. Without this, almost no air is going over the radiator untill the fans kick in and their not strong enough to keep it cool at speeds over 35mph.

 

B

 

Well i built an air dam out of some abs plastic installed another water pump and a new t stat both new hoses and its cured!!!!! I also had 5 and 7 plug wires swapped. Yes im an idiot lol thanks for all the help guys