1939 chevy master deluxe sedan over heats

Bountyhunter said:

i bought a 1939 chevy master deluxe sedan with a 454 engine and turbo 400 tranny 6 months ago and am finding many issues that need to be sorted out. The car was a frame off custom build in 1997 and sat in the dealers showroom for 16 years. Current problem came up when the radiator blew out several months ago and I had a shop pull the old radiator and I took it to a radiator shop with a good reputation. He would only rebuild the radiator in copper, which was expensive. The core was made in Texas and is 17.5 wide x 22 long and 4 inches thick. I had the 6 blade mechanical water pump fan and shroud that never looked right. The engine was tuned and flushed. Went out the other day and quickly overheated above 220. I have pulled the shroud and fan out and want to change over to an electric radiator fan. Today I talked to a custom shroud company in michigan and he said forget the shroud and puller fan because the radiator is 4in thick plus the ac condenser and tranny cooler are attached to the front of the radiator. He suggested using only a large pusher fan and put the water pump fan without the shroud back on. There are a lot of smart people out there, but different opinions and ways to solve problems. I have room at the back of the radiator for a shroud and puller or I can move the ac condenser forward to use a pusher. Any real time solutions will be appriciated.

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35WINDOW said:

Obviously the 454 fills the engine bay-I assume it has a Hood, so I would first pull the Hood and see if it is air not being able to get out of the engine bay (does it overheat in traffic and/or on the Highway)?
Secondly, the Fan setup does sound a little wonky, and an electric fan may help-
I have a 540 BBC (850 hp) in my '35 Ford, and was so concerned regarding airflow that I located my A/C Condenser under my front fender (with a electric fan/shielding) and mounted my Tranny Cooler under the Car (also with an electric fan/thermostat)-
I am running a 4 tube copper radiator, and due to a tight engine compartment a 17" Spal pusher curved blade fan and louvered inner Fenders-
I also have a 160 degree Thermostat and overflow Tank-
With this configat a light uration, it has never gone over 180 degrees (on a 105 degree day)-
Make sure your fan belt is tight-you may also have to run a cooler on your engine oil (it will help)-

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35WINDOW said:

Obviously the 454 fills the engine bay-I assume it has a Hood, so I would first pull the Hood and see if it is air not being able to get out of the engine bay (does it overheat in traffic and/or on the Highway)?
Secondly, the Fan setup does sound a little wonky, and an electric fan may help-
I have a 540 BBC (850 hp) in my '35 Ford, and was so concerned regarding airflow that I located my A/C Condenser under my front fender (with a electric fan/shielding) and mounted my Tranny Cooler under the Car (also with an electric fan/thermostat)-
I am running a 4 tube copper radiator, and due to a tight engine compartment a 17" Spal pusher curved blade fan and louvered inner Fenders-
I also have a 160 degree Thermostat and overflow Tank-
With this configuration, it has never gone over 180 degrees (on a 105 degree day)-
Make sure your fan belt is tight-you may also have to run a cooler on your engine oil (it will help)-

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wave1957 said:

Maybe not a ready-made solution, but comments on your issue...
Main thing is to know if your car overheats while highway driving, or while idling/driving in town. Typically, overheating at speed means not enough rad (or sometimes, grille too small to let in enough airflow), overheating while idling means not enough fan (or no shroud, or bad fan, or fan too far from rad without a shroud...). Hot air also needs a way to escape from the engine compartment.
The best way to cool an engine reliably (if possible, and in your case, it seems clearly possible) is to use a factory-style (no flex-fan...) clutch fan with the clutch and a shroud, which in your case will most probably have to be custom-made (a search here will bring up how-tos). Such a set-up has worked in millions of stock vehicles,including hard-working trucks with 454s... Such a set-up will also move enough air for A/C. And it is easier than going electric!
Then, I do not understand why a fan shroud company would recommend a pusher electric fan, as they tend to impede air flow at speed...
Do make sure that all the air entering the grill actually goes through the rad, and cannot go around it: the area around the rad needs to be sealed.

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Ford blue blood said:

There is an outfit that make a puller fan/shroud assembly that will work. Cooling Components makes a really nice assembly that works well. They are pricey but worth every penny!

Info on when over heating will help. On the road at speed I found through a friend having this issue that the deleted inner fender panels on his 35 Chevy were the culprit. The fenders were scooping in air restricting flow through the engine compartment. Made new panels and the issue went away.

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ogre said:

i thought it was overheating? 220° is not overheating and honestly if that's all the hotter it's getting, i wouldn't worry about it. 50/50 antifreeze with a 16 lb cap won't boil until 267°, engine oil is good to 280° before it starts degrading. i'm not saying that you should run a motor at those temps, but 220° forever won't hurt anything. someone stuffed 10lbs of poo into a 5lb bag.

View attachment 630170

that said, next time you change the oil, look for plastic in the oil. gm was famous for plastic coated timing gears, the plastic would break off and basically reset the timing. also change where you read the temps. i had a 396 that rusted a hole bigger in a head gasket that affected the flow around the temp sensor on the back of the head. the motor wasn't overheating, just the antifreeze around the temp sensor.

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Ford blue blood said:

The hood should have vents in it. Air needs to move. The three to four vent in the rear of the inner fender will not move enough air IMHO.

Yup, in town heating is a real pain! Not enough air moving. As mentioned before the Cooling Components system works well. The shroud has flaps on the lower portion to let air through while on the road and stay closed as the fan is pulling air through. It is a complete system designed to fit your car (or most other early cars) and installs cleanly. It does require a 60 amp fuse, mostly the high current is starting draw. I have always put the fans on a relay run by a temp sensor or by a trinary switch in the AC high pressure line. No need to run the fan when on the highway.

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Bountyhunter said:

Thanks for your reply, It is heating to over 220 + gauge doesn't read in enough increments. It has new 16# cap and full flush out, but when I pulled into the garage and shut off the engine, it dumped new antifreeze all over the floor. I'm currently going over everything to see what's going on.

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BogiesAnnex1 said:

The problem is there is no substitute for flat face area which is lacking due to space restrictions. Each successive tow of tubes is less effective than the row or rows ahead of any row. This relates to what the design engineers call “delta T”. This is the difference in temperature of the cooling medium in this case air passing over the tubes and fins and the item to be cooled n this case engine coolant passing through the tubes while those tubes surrender heat to the fins. So each successive row of tubes sees a hotter cooling medium and is therefore less effective than the row ahead. The same happens with the fins in that the front of the fins sees cooler air thus has a higher rate of heat transfer than the back side of that same fin.

So the rub is adding thickness is no where as effective as adding face area and we know by practical example that three rows thick is really the practical limit of adding rows over increasing face area. Then in your case this is made worse because the engine’s radiator is behind that of the air conditioners which for the face area that occupies essentially adds more tube rows of heat to the incoming air and that fin structure more aerodynamic resistance to air flow.

For the area you have there is no electric fan that can compete with an engine driven fan for CFM pulled or pushed through there cores. The problem with any fan front or rear mounted mounted is flow resistance through through the core presented by these elements. When you read flow numbers for electric fans these are calculated free flow. Now for a given fan blade count and configuration being same similar consider the power of an electric motor spinning that fan compared to what a 454 can put into spinning a fan then you start to get an idea of how rational advertising claims can be.

The OEMs tend toward sucking fans and shrouds be they electric or engine driven. The electric fans the OEM’s use are really part of the fuel mileage and emissions games they and the EPA and DOT play. For the duration of these tests using an electric fan transfers direct power pull from the crankshaft and puts it on the vehicle’s battery which of course tor these tests is new and fully charged not a 5 year old from O’Rdilly’s. Plus for transverse mounted engines of front wheel drive electric fans are a simpler solution to right angle drives.

Probably the best GM fan is the reinforced plastic fan of either 9 or 11 blades they’ve been using for many years on light trucks. Unfortunately these are only available for reverse rotation (counter clockwise) serpentine belt drives. But regardless of how much power applied to the fan there is a point where flow resistance through the radiator’s peaks and adding more power on the fan cannot overcome this in the sense that the flow gains get proportionally smaller per added horse power till the flow stalls. One has to remember that air is compressible which in a way is saying it’s elastic. So unlike water where the number of molecules in a cubic foot of water from the bottom of the Mariana’s Trench is essentially the same as a cubic foot of water scooped out of the surf in LaJolla. This is not true of air in that a cubic foot of air captured from the stratosphere does not contain the same count of molecules as a cubic foot of air captured at Furnace Creek, Death Valley. This latter gets into why measuring CFM in head ports isn’t a full expiation of cylinder head power, but that’s a different and longer story.

The lack of the shroud is a detriment in that it performs two functions; first it forces as much air flow as efficiently possible to pass through the total face area of the radiator, assuming no leak paths exist between the radiator face and the shroud air outlet. Secondly, the fan is positioned in the shroud such that the blades are captured mostly within the shroud so that air being slung off the ends of the blades is forced to exit to the rear of the shroud.

Air out is important having stuffed a lot of V8’s into tight spaces it becomes apparent that just getting the air out becomes a headache. I rather accidentally discover one cool near foggy morning that my idling 350 powered S15 pressurized the engine compartment sufficiently that hot air was blowing out around the headlight bezels. I could see the hot wet air condensing to a mist as it flowed out around the headlights. So there may be something to be gained in your case with hood louvers.

A trick I got into with these big V8’s in small engine rooms has been to clamp pipe to the frame circulate coolant inconspicuously around the vehicle. This adds quite a bit of volume and uses the frame as a heat sink. It’s quite helpful but a PIA to install.

Bogie

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RWENUTS said:

Doesn’t sound like you have a catch can coolant overflow return set up.
if not don’t fill the rad right to the top, fill it to about 2-3 inches from the top.

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BogiesAnnex1 said:

Modern cooling systems use an expansion tank as well as an overflow tank.

In the OEM design world the needed coolant volume is calculated then an extra volume within the system flow is included to allow the coolant to expand when it gets hot but that volume is contained so volume is retained rather than lost from circulation to a bypass recovery tank. Classic design would and was to size the needed volume and bypass the expansion to a recovery tank.

But of course in service most everybody just fills the system to whatever capacity it will hold so any heat expansion just vents to the recovery bypass tank where it will be drawn back in as the coolant cools and contracts making a vacuum that atmospheric pressure on the vented volume will push back into the radiator.

Bogie

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Ford blue blood said:

The hood should have vents in it. Air needs to move. The three to four vent in the rear of the inner fender will not move enough air IMHO.

Yup, in town heating is a real pain! Not enough air moving. As mentioned before the Cooling Components system works well. The shroud has flaps on the lower portion to let air through while on the road and stay closed as the fan is pulling air through. It is a complete system designed to fit your car (or most other early cars) and installs cleanly. It does require a 60 amp fuse, mostly the high current is starting draw. I have always put the fans on a relay run by a temp sensor or by a trinary switch in the AC high pressure line. No need to run the fan when on the highway.

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Bountyhunter said:

maybe I should install a recovery tank?

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ogre said:

you can, but until then quit refilling the radiator.
let it puke all over and get it out of the way.
there's no cooling capacity in the top tank, just keep it half full

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