finally figuring out overheating

[Johnnydidd]

I been very active on the board title evap-o-rust. I visited with Bob at Baxter Ford in Lawrence, we discussed my overheating problem, the part where I slow down and the temp goes down. this is pretty simple really when I slow down I don't need as much air to pass through the radiator as I need at 75 mph. The electric fan an shroud completely covers the radiator only allowing so much air to pass through. need to remove electric fan an use 4 to six blade fan, not using a shroud, so as much air will pass through as possable

[RKS.PA]

I found Bob at Baxter Ford to be very knowledgeable. He helped me calibrate my speedometer on my '39 and got me the right "turtle" gear.

Don't throw the electric fan away until you see how the engine mounted fan performs.

Hope this solves your problem.

Dick.

[George/Maine]

My 39 Ford sedan with a mercury 8ba was running hot I put a coolant electric fan sold by Walker and found out with fan off doing say 50mph it would run hotter.
I cut off the lower shroud so as to get more flow, they do put rubber flaps on bottom to help the flow of air. I only put fan on in traffic. I run a 12 volt fan.

[1931 flamingo]

I've been following your "journey".

Have you addressed the radiator?? Clean?? Rodded out??
Use a digital hand held temp gauge at diff spots on your radiator at operating temp. Should be diff temp top to bottom. FWIW
Paul in CT

[flatheadmurre]

You had an aftermarket core if i dont remember wrong.
It is more efficient so its less easy for the air to pass then an original.
Taking the shroud away makes the fan very unefficient.
So if it will work better without a shroud only means your fan aint doing the job.
Drop the electric one to start with then try a truckfan thats what i would do.

[Johnnydidd]

Sponsored Links (Register now to hide all advertisements)

I got a 6 blade fan I am going to try, wont know till next week how it works, I have to have an adapter made so fan will fit.

[40cpe]

If you are determined to try this, I would remove the fan and shroud and try it on the road. Above 30-40 mph you shouldn't need a fan. If the car cools at 70 as well as at 55, maybe the shroud was part of the problem. If it still runs hotter (too hot), you don't have enough radiator capacity.

[G.M.]

Originally Posted by 40cpe

If you are determined to try this, I would remove the fan and shroud and try it on the road. Above 30-40 mph you shouldn't need a fan. If the car cools at 70 as well as at 55, maybe the shroud was part of the problem. If it still runs hotter (too hot), you don't have enough radiator capacity.

I think it would be more like not enough coolant flowing through the radiator. A restriction, poor pumps or low coolant lever would cause this condition. Coolant lose from non working pressure cap allowing coolant to back out the over flow tube. G.M.

[HELENT]

good day i had the same deal with my 46 running hot did ever thing you can do took my air condition condenser off ran cool move it under the front bumper look at my album may help

[Mike51Merc]

One thing to remember is that fans (electric and mechanical) are only needed (and useful) for slow speed driving. There is no fan that can match the airflow that nature provides at highway speeds. As a matter of fact, a fan is more of an obstacle on the highway than a benefit.

So, with that in mind if you are overheating at highway speeds, there is either a serious engine problem or your fans are blocking the air.

[Johnnydidd]

Do you think 6 blade fan will do more harm than good, it had a 4 blade fan on it before I put on air, it ran a little hot not bad. I think I will try the 4 blade and see the how it works with air.

I appreciate all the help you have provided, makes me look things I haven't though about.

[51 MERC-CT]

Originally Posted by Johnnydidd

Do you think 6 blade fan will do more harm than good, it had a 4 blade fan on it before I put on air, it ran a little hot not bad. I think I will try the 4 blade and see the how it works with air.

I appreciate all the help you have provided, makes me look things I haven't though about.

I'm running a 7 blade flex fan and it pumps a lot more air than the original 4 blade.
Especially at idle.
It's off of a 78' Granada.

[JSeery]

With an A/C condenser and an electric fan blocking air flow through the radiator it is not surprising there are heat issues.

[flatford8]

I have a six blade after market flex fan and it pulls a huge amount of air. I dont notice alot of noise but it has been on the motor since I bought the car....... MARK

[FlatheadTed]

I was testing a 32 tall coil on my 34 as a result I could not run the fan ,at highway speeds I was surprised to see the Temperature rise . My conclusion was that at 50MPH the fan is assisting and sucking a high amount of air .My radiator tube design was not ideal so radiator affiance was on the low side .I rectified this by adding a shroud which makes it suck even more air at high way speeds .and now it runs on the cool side .At the lights the shroud really comes into its own .In some cases you can run these cars with out a fan but its not a hard fast rule as there seem to be lots of variations .Ted

[johnh7]

I installed a 12 volt 18" puller [3000 cfm] fan, thermal switch and a walker shroud on my 38 Pickup. I had no heating problems before the installation, but needed to replace the 16" 6 volt fan. I thought the shroud would improve air flow and help to cool the engine even better. I was wrong. The shroud fit the radiator perfectly, but seemed to really restrict air flow. The engine ran hot at highway speeds and while stopped at stop signs. That had never happened before.

I removed the shroud and installed the fan directly on the radiator. Now there is plenty of air flow and the engine again runs cool. In town at stop lights it will heat up to 185 and the fan comes on and keeps the engine cool. Once out of town and on the road the engine cools down and the fan shuts off. For me the shroud absolutely did not work! It acted as an air dam and made the engine overheat. Not enough air could flow through the 18" hole in the shroud. Even with the fan on, the engine ran very hot with the fan shroud. Without the fan shroud everything is fine! The new fan moves much more air than the old fan did and without the fan shroud it keeps the engine cool while stopped.

[tubman]

Just to add some more information, the fan bearing on my '51 started making noise, so I decided to replace it. In the interim, I had a '51 Mercury fan assembly (without a fan on it) that I decided to run in the interim. It didn't work at all well without a fan (got hot real fast), so I bought an aftermarket six blade aluminum fan. It works OK, but doesn't seem to work any better than the stock 3 blade fan. My car is completely stock (no shroud). I think that the Ford engineers had this all figured out, and that adding a shroud and more blades screws up the designed airflow. After I put in my recored radiator in 1987, I have never had an overheating problem. Maybe I'm just lucky, but this isn't the first time that I found that the original design was right on.

[Johnnydidd]

I am fighting between taking the shroud off using the electric fan or using the 4 blade ford fan or using the six bladed fan mechanical????????????????

[Kahuna]

Johnny
Look closely at HELENT's album
May be your answer with the AC
Seems to work well

[Joe Immler]

I have heard that the engine blade fan can be installed backwards. Is this true ?
Since this post is about fans I thought I would ask. I know my '41 fan has a metal strip that the blades are riveted to.That is my guide for installation. Just wunderin.