57 chevy getting hot gradually!

[BFS57]

Hello;
My 57 chevy seems to have this overheating issue (been doing it for quite a while) while Im driving, it seems to get hotter and hotter gradually! (tased some time)
I changed my radiator from a Champion with 3 row tubes (combined 1.8 inches volume) to an aluminum radiator with two rows of 1.25 inches (combined 2.5 inches volume) didn't help! Im running a Cooling Components fan with shroud. Also have a temp control switch on it that works perfect. Have a serpentine system with a reverse rotation high volume water pump.
Thats about it on this car. I did have a problem with the temp sender on the gage (Dakota Digital) which i added a diode on it to be at correct temperature on the gage! Used a digital temp laser to figure this one.
I just finished my ac charge and the system blows ice cubes! But it does not seem to be the culprit As I drive it, it seems to get hotter and hotter going past 220 deg. If I stop and shut it off, the temp goes down according to how long I park it!? Also have a 160 deg. thermostat!
My engine is a pretty much stock 350 small block!! No performance mods!!
Anyone got any suggestions or answers based on my symptoms?
Any advise greatly appreciated.

Bruce

[enjenjo]

Heating up at speed is usually air flow, or coolant flow. You seem to have the right parts to address both of these, but you still have a problem. So lets look at that.

With a well designed system a 160 degree thermostat  is not needed. If you stop and think about it, it doesn't limit how hot the engine gets, just how soon the radiator comes into play. If the engine continues to get hotter above the thermostat rated temperature, either the thermostat is not working properly, or it's restricting flow. They are both possibilities. The quality of thermostats has declined sharply in the last few years, to the point I will only use name brand thermostats. I prefer the FlowKooler Robertshaw thermostats because they are high quality with exceptional flow. The old trick of using a washer in place of a thermostat works because it breaks up the laminar flow of the water, causing more of the water to contact the inner surface of the radiator tubes. The Robertshaw thermostat does pretty much the same thing  by having an annular opening that causes the same turbulence in the coolant.

Once the rated temperature of the thermostat is reached, and it opens, it no longer affects the coolant temperature, so at 220 degrees, a 195 thermostat is as good as a 160 thermostat, as long as it isn't restricting flow. With the added benefit of raising engine efficiency for more power and better mileage.

Now lets discuss air flow. I am assuming you have one of the dual electric fan kits. This should be very efficient. But what if the air is not going through the radiator. If your 57 is set up like most there is no baffle between the top of the core support, and the bottom of the hood. This can allow the air to flow over the top and never go through the radiator. Air flow, like water flows to the least resistance. The same can happen under the radiator, particularly if there is a high pressure area behind the radiator. Remember there is an AC condenser, the radiator, and the cooling fans all restricting flow in that area. You can build some corrugated cardboard air dams to test this.

Let me know if any of this helps

[348tripower]

What kind of hoses do you have on the radiator? I have heard of problems with the fancy flex chrome ones causing cooling problems. I would recommend silicone hose and aluminum couplers for building special hoses. I used these on the wagon with great results.

[BFS57]

Hello;
I agree with you on the fact that the thermostadt might be the culprit.
When I built my car I used a hood that is basically flat no hood "rockets" but I did take the brace out of the old metal hood and perminently (with screws) attach it to the radiator cross brace. Thats not to say that there is air going over the top of that so I will see if there is any place thats letting air go by.
About the bottom, I have not paid particular attention to this, bit I will now!
My fan (1) is behind the radiator comes on at 170 the measurements are provided by a Davies Craig digital switch reading temps direct from the radiator core via probe.This fan is also a shroud and really is a good unit!
In front of my radiator is the ac condenser it has 2 10" pushers mounted in front of it and they come on when the ac is turned on.
At one point I had a large 1/8" thick plastic piece cut to fit the front of the car from the grill brace to the radiator brace. Maybe I should experiment with something like that again.
As far as hoses go I have the good old rubber (stock) ones. Regular at the bottom  a "springy" one at the top!
Ill start looking for the thermostat first and go from there. What temp range would be a good one?
Thanks for the info guys

Bruce

[WZ JUNK]

I know from experience that the sheet metal panel under the hood, that runs from side to side, and aligns with the top of the core support,  makes a big difference.  A friend was having trouble cooling at interstate speed and I noticed he had removed that panel when he built the car.  When he reinstalled the panel, his heating problem went away.  The panel keeps all the air that comes in through the grille opening going through the radiator, and it keeps the hot air, of the engine compartment, from reentering the radiator.

I am using a separate trans cooler and engine oil cooler on my current project to reduce the heat transfer in the radiator.  By keeping the hot transmission fluid out of the radiator it should work better at cooling.  The engine oil cooler should also help take some of the load off of the radiator by dissipating some of the heat of the engine.

John

[Bruce Dorsi]

How much space between the a/c condenser and the radiator?

What is the ignition timing at cruising rpm?

[papastoyss]

Hello;
I agree with you on the fact that the thermostadt might be the culprit.
When I built my car I used a hood that is basically flat no hood "rockets" but I did take the brace out of the old metal hood and perminently (with screws) attach it to the radiator cross brace. Thats not to say that there is air going over the top of that so I will see if there is any place thats letting air go by.
About the bottom, I have not paid particular attention to this, bit I will now!
My fan (1) is behind the radiator comes on at 170 the measurements are provided by a Davies Craig digital switch reading temps direct from the radiator core via probe.This fan is also a shroud and really is a good unit!
In front of my radiator is the ac condenser it has 2 10" pushers mounted in front of it and they come on when the ac is turned on.
At one point I had a large 1/8" thick plastic piece cut to fit the front of the car from the grill brace to the radiator brace. Maybe I should experiment with something like that again.
As far as hoses go I have the good old rubber (stock) ones. Regular at the bottom  a "springy" one at the top!
Ill start looking for the thermostat first and go from there. What temp range would be a good one?
Thanks for the info guys

Bruce

If the Robertshaw thermostat (highly recommended) doesn't cure your problem , think about installing a trinary switch in the a/c line that will turn  on your Cooling Components rad fan when needed & ditch the fans in front of the condenser which can restrict air flow.

[BFS57]

Hello;
Ran the car the other day hot as hell here!!! Im thinking of re resurrecting the air dams I had only with more logic.
I just bought a new TV so I have lots of cardboard!!!

Bruce