I have a 1957 312cu with the G heads  and 570 cmf Holley on it with 3spd OD and a 3 bladed fan.  Runs great  does not over heat even with this 90 degree weather.   In slow traffic it pushes up pretty close to 200.  Which then when I park it must push it way up.  So was wondering if a 4 blade would help?  Or I could mount electric fan on radiator with thermostat as I have do on others that I had with heating issuse.  Would like some input to push me off fence.

The next fan to try is a Ford 4 blade the fan for a 312 will have stamped on one of the blades SC

If the temperature stabilizes at 200 then I don't think there is any issue but if it keeps climbing and could potentially overheat in really bad traffic, then it is something worth looking at.

Two easy things to try is a fan with more blades and / or a smaller diameter water pump pulley.  A smaller pulley increases fan speed AND coolant flow.  If a smaller pulley solves the problem, then it may not be the fan.  It could be that low speed coolant flow was insufficient.  The stock passenger car pulley is quite large and could contribute to overheating in modern traffic.


Lawrenceville, GA

As a general rule of thumb an engine with its cooling system in good shape will run about 100F above ambient temperature so 200 on a 90 degree day sounds reasonable to me. I don't think adding more blades will help when help isn't needed. As long as it doesn't boil over I would do nothing more than keep an eye on it. When you park it the temperature will climb since there is no coolant flowing and little to no air flow through the radiator. It should return to normal operating temperature when you start driving again. 

My  55 TBird has a similar engine and transmission.  I have an aluminum radiator and a single electric fan. I do not have a fan drive off my water pump. I also have a high flow 170 degree thermostat.  It's hot in Central Florida.  I experienced similar issues when sitting in traffic and parking. I recently purchased the improved TBird water pump from Casco.  It has deeper fins to make up for the water pump spacer used in these cars. What a difference!   Every early TBird owner should run this pump. 

If you have a 57 BIRD w/ a three blade fan, it is incorrect assembly.

1955/mid-1956 was three blade and when FORD went to a coolant cooled FM, they also went with a four blade fan -

FAN BLADE -

FAN PULLEY -


FAN SPACER -

____________________________

Melly didn't say in the original post, what model of car his engines in..??  It's known that T.Birds are more prone to running hot than sedans etc.  


Paul

My ‘55 Customline has the original 3 blade fan, no fan shroud, and that fan is a reasonable distance from the radiator.  All factory.  Same scenario in that if caught at traffic lights or very slow moving traffic the engine temperature will slowly rise up to 200°F.  As soon as the car is moving, the temperature always comes back down.  No spitting of coolant so I have never seen a need to improve the low speed air flow characteristics through the radiator on that particular car.

I did have a cooling issue on my ‘66 Fairlane that started when installing a new 3 core radiator versus the two core radiator it originally had.  I originally had a fiberglass flex fan with the two core radiator but when switching to the three core radiator, that proved to be insufficient.  Switching to a five blade fan with offset blades solved that problem.  The downside is it does sound like a wind tunnel now though when the rpm is up.

Lorena, Texas (South of Waco)

Ted, the Studebaker guys found that the replacement radiators had too many fins, so no matter how many tubes and rows they had, there was not sufficient air flow to cool the engines.  Just a thought.

John - "The Hoosier Hurricane"

John. When I went to purchase a new radiator for the ‘66 Fairlane, a bolt in 2 core was no longer available so a 3 core it ended up being.   I would have preferred the two core as the car had no heating issues even with a 'hot' 427 FE.  Air flow through the 3 core is definitely restricted.   I remember my Father talking about adding additional cores to radiators in his 337” Flathead powered grain trucks in the early Fifties and he commented that it did not help in cooling down those grain trucks.

My roadster is a two core but a triple pass.  It’s only 1 foot square but does a good job in cooling down the 500+HP Y.

Lorena, Texas (South of Waco)