1956 Thunderbird runs hot / overheating

[Medal5]

My 56 runs hot in the summer. In the fall and the rest of the year it runs fairly normal unless I am in bumper to bumper traffic. I have added an aluminum radiator, a 3200 CFM electric radiator fan, a high input water pump, and added water wetter to the radiator. But when I restored the car and had a new valve job, overhauled the transmission, new fly wheel, I also added an air conditioner. But the air conditioner's condenser is located right in front of the radiator and covering it completely. I am wondering if this is preventing air from the outside from entering the radiator normally. Should I remove the air conditioner and condenser? Will this help? Or is there another remedy? How is this Evans coolant? Is it effective and OK to use?
Thanks

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[Bandit]

Is your elec fan on the front of your ac cond, if so it will actually block air flow. If you are going to run a elec fan it should have a shroud and be placed on the engine side of radiator . Cooling Components make shrouded elec fans in many different sizes. You also don't want the water flowing thru the rad too quickley.
Carb jetting is another area that can cause heating issues, a lean carb will overheat quickly.

 

[TeeZee]

Medal5,
I have a '55 I converted to 12 volt so I could run AC. But, even on a cool day (in Florida) with the AC off and top down, my car would overheat in parades. I even tried the trick: turning on the heater to no avail. But once at speed the engine cools.
Turns out that up to 750 RPM and possibly higher, the coolant flow is negligible. The Ford Thunderbird water pump and spacer was a compromised design. Christopher Ames published an article in the Early Bird, Jan-Feb 2017 where he graphically presents the coolant flow vs RPM. He does provide a solution as well. A modification to the spacer between the water pump and block resulted in significant cooling flow at 750 RPM. The spacer is expensive compared to the baffle or high output water pump, but compared to the cost of the AC installation it is cheap.
I have also tried the Evan Waterless coolant in another car (MGB), but I also switched to a new aluminum radiator, plastic fan, and new heater core during a complete engine overhaul. The engine did not have an issue cooling at idle (bumper-to-bumper traffic), but the coolant approached HOT at highway speed on hot days. Now the Evan coolant barely reaches 180 F, while maintaining cruising speed on I95. I am happy with the Evans Coolant, but have not applied it to my Tbird
I suggest, besides obtaining best tuning, the coolant flow issue be addressed.

 

[Tchristian]

You mentioned adding a high input water pump. Was that a Casco modified pump? The problem the baby birds have with cooling comes in large part from the spacer between the block and the pump. The impellers on the stock pump did not reach deep enough into the spacer to get adequate flow. I got the Casco pump (which is a stock pump with deeper impeller blades attached) and it seems to work fine. I tried the baffle, but it is really a non-solution. Although it increases pressure and velocity, it reduces the volume of water moving through the engine. The more water by volume, the greater the capacity for heat exchange. Moving it faster doesn't give the water enough time for heat exchange at either the motor or the radiator.

 

[CSPIDY]

The problem is usually when idling, there is not enough airflow or water flow, in fact at idle with stock water pump and spacer there is no flow. The new spacer, dual water pump, wide mouth thermostat from, CASCO and the small pulley they offer will ensure water flow. The electric fan will ensure airflow. The aluminum radiator helps a lot as well. I have done all this plus blocked the bypass and have no overheating problems Evan on the hottest days with AC on.

 

[ICON 56]

My radiator is aluminum and the added fan shroud cover does help, I have never over heated so far well I just had the car for a few months...The previous owner had dual water pump and added the wide mouth thermostat. This was done by Jewel Meets in Brillion Wisconsin.

 

[zeroroadkill]

The problem is usually when idling, there is not enough airflow or water flow, in fact at idle with stock water pump and spacer there is no flow. The new spacer, dual water pump, wide mouth thermostat from, CASCO and the small pulley they offer will ensure water flow. The electric fan will ensure airflow. The aluminum radiator helps a lot as well. I have done all this plus blocked the bypass and have no overheating problems Evan on the hottest days with AC on.

How did you bypass the bypass hose? Would that increase flow? I often wondered why there was a bypass hose in the thermostat housing.

 

[George K]

George K
New and first post. May be in wrong place. On my 56, I have replaced radiator 4 core, 6 blade fan, new Casco water pump, wide mouth t,stat ,checked heat valve in exhaust and it still overheats in traffic. I see someone mention a new spacer and dual water pump. Is this something new and better than the Casco pump. It is a total ground up, body off restoration. Has about 5000 miles on rebuild. Ideas would be appreciated.

 

[Ward 57]

Sounds like you have done due diligence. Something as simple as timing and fuel flow can make an engine run hot at lower rpm. I'm sure there are several on here that know how to tune that way.

 

[55blacktie]

Medal5, did your car overheat before the valve job? The head gaskets could have been installed backwards, thereby restricting coolant flow. Anything placed in front of the radiator can, to some extent, restrict air flow, but the majority of T-bird owners/w ac put an auxiliary fan in front of the radiator and condenser, where yours is located. I have seen once instance where the water pump spacer was removed and both mechanical and electric fans were used on the engine-side of the radiator. Using a plastic fan? What's the diameter? Number of blades? Are you using a shroud? A 1-inch smaller pulley will increase water pump and fan speed at idle.

Cspidy, what is a "double water pump?"

 

[Ward 57]

I think you are looking in the right direction especially about the head gaskets. They may fit upside down or reversed blocking unknowingly blocking coolant flow. I know there is a way to check externally but can't remember the tell tales.

 

[paul5456]

CASCO has an improved lower shroud piece for the radiator. The factory piece does nothing for coolng

 

[Ward 57]

CASCO has an improved lower shroud piece for the radiator. The factory piece does nothing for coolng

Hmm, Mine seems to fit pretty well with the fan. What did they change?

 

[Douglemmo]

In some of the above posts there is mention of a "dual water pump" can anyone explain what they are talking about,?. I know about the modifications to the stock pump to increase flow, but what is a dual pump?

 

[doug7740]

I think you are looking in the right direction especially about the head gaskets. They may fit upside down or reversed blocking unknowingly blocking coolant flow. I know there is a way to check externally but can't remember the tell tales.

Since the head gaskets used on a Y-block engine are identical, it might seem like you would install the same side of the gasket against the heads on both sides of the engine. This is not the case. What is critical is that the open coolant holes are at the back of the head and the blocked portion of the gasket is at the front. Look for the word FRONT on the gasket and place it at the front even if it looks wrong. This places one of the gaskets face up and one face down. Notice that there is a square corner at one end of the gasket; this must be at the front of the engine. This can be checked without removing the heads. If you are having overheating problems check for these square corners at the top front corner of the head near the intake gasket.

doug7740
1955 Thunderbird Blue

 

[doug7740]

In some of the above posts there is mention of a "dual water pump" can anyone explain what they are talking about,?. I know about the modifications to the stock pump to increase flow, but what is a dual pump?

I think what they are referring is the high output water pump that CASCO sells. I installed this pump on my T-bird engine without using the modified spacer and it took care of my running hot at idle issues.

doug7740
1955 Thunderbird Blue

 

[Critterpainer]

There is also a re-engineered water pump spacer available that increases water flow at an idle. If your car gets hot at idle, this will help with that issue. The stock spacer does not let water circulate at idle speed.

 

[doug7740]

There is also a re-engineered water pump spacer available that increases water flow at an idle. If your car gets hot at idle, this will help with that issue. The stock spacer does not let water circulate at idle speed.

I installed the CASCO high output water pump with the stock spacer, the water circulation was increased and it took care of my car running hot at idle.

doug7740
1955 Thunderbird Blue

 

[CSPIDY]

Cspidy, what is a "double water pump?"

For clarity,
The original water pump only had pump blades on the forward side of the pump.
There were no pump blades in the spacer side as ilistrated in Doug’s post.

I was still having an overheating problem at idle on my 57 with the dual/high output pump installed.
After installing the spacer mine doesn’t increase in temperature while idling.

 

[Billy-Bird-FiveSeven]

Working on getting my 57 to run cooler. An aluminum radiator with electric fans was installed. I fixed a bad wire on the temp sensor. Currently runs about the 3/4 mark on gauge now in various driving conditions. BUT, it is still cool weather here in North Carolina. I replaced the upper radiator hose(puncture), by-pass hose, and installed the 170 degree large opening thermostat. Long story short, pulled thermostat and replaced with the existing180 degree after seeing this...(see attached photo of scratch (grind) marks on thermostat). It appears it was making contact with the inside of the intake housing? Wore off the embosed numbers on T-stat. I did cut off the heater valve pipe to just past the threads.

Would it be safe to re-install this thermostat?