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chstickl

Belt fan or electric fan, that is here the question-

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Hi there,

because of notorious overheating I brought the radiator of my 37 Special Coupe to a restorer who will exchange the cool web into a high performance one, but use the lower and upper shell of the original rad. He offered to also foresee a thread for a thermo switch and besides recommended to remove the fan blades from the water pump and use an electric auxiliary fan with a thermo switch instead. (I have to say that he is a well known radiator restorer for old cars and I´d assume that he knows what he is talking about, but his main experience may come from allways overheating Jaguars or Austins.) He said that the advantages are:

- lower noise

- longer life for the water pump

- about 10 hp more

Since I have a 12V conversion, it should be easy to find a good electric fan. My questions now:

Should I do it at all?? (normally I am a proponent of original)

Anybody has done this? Experience?

Where to place the thermo switch? at the top of the rad with a 190 fahrenheit switch point, or at the bottom of the rad with a 120 fahrenheit switch point?

Thanks for your recommendations

Chris

P.S. yes, I know that I should look at all other reasons for overheating first and I´ve done it. Ignition timing is perfect, vacuum and rpm advance works fine. Carbon monoxide (carburator) is in good range, spark plugs look perfect, tried to clean the engine block several times by flushing and with acid. Water pump is ok, thermostat works well, etc.

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Chris,

Why not do both ?

On my '40, which lives at 8500 ft in the Rocky Mountains, I replaced my funky looking 5 blade fan with a 6 blade "flex: fan and I added an electric "pancake" fan to the front side on a hidden toggle switch. The electric unit is used mainly in the summer, on those long uphill pulls, and sure helps keep those "vapor lock" gremlins away.

Mike in Colorado

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I installed an electric fan in front of my radiator this past summer when I went 12 volt with A/C. It is on a thermo switch, but I put in a hidden toggle so I can turn it on if I need to for overheating. It worked very well on the tours we did in July, August and September here in Texas.

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I think it is a case of "DO YOU WANT FRIES WITH THAT?" or "DO YOU WANT TO SUPERSIZE IT?".

I would see if the new radiator core solves the problem first.

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I think it is a case of "DO YOU WANT FRIES WITH THAT?" or "DO YOU WANT TO SUPERSIZE IT?".

I would see if the new radiator core solves the problem first.

+1 and I would also think about figuring out a way to REALLY clean out the block. These engines, while very well designed, were prone to collect junk (sand, rust etc.) in the water jacket. While an acid flush will help descale it will do little or nothing to remove the compacted stuff in the lower water jacket. What may need to be done is to remove the freeze plugs and any other opening plugs into the water jacket and go after it with a stiff wire, pressure washer, flushing stream and/or anything else you can think of. Another thing to look into is to modify the thermostat housing to remove the spring bypass valve and replace it with a fixed orface bypass. It is not uncommon for the spring bypass to allow coolant to bypass the radiator at higher engine speeds leading to overheating. Just my thoughts.

Robin

PS: I am a purest and vote for as stock as possible, but with the 12 volt mods that is already a moot point so either way will work provided that the problem is airflow which I strongly doubt...

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You might want to consider the fact that the engine did run OK without overheating when it was new.

You can add all the bells and whistles on the front, but as mentioned above if you dont get ALL the crud out of the block first, the only thing that will occur is that your wallet will empty.

I have had my '38 Roadmaster run at correct temperature going uphill in slow traffic on very hot days. I feel one of the reason it does work OK is that when I had the engine out, I knocked the core plugs out and managed to scrape 1/2 of a 5 gallon bucket of crud out of the block. You first have to get the heat into the water.

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