The Stovebolt Site Forums The Shop Area Engine Shop 235 Cooling Problem

My 1956 235 engine is having trouble staying cool. It is a fresh rebuild with everything new, except the radiator was "rebuilt" (Cleaned). It has a new water pump with a 6" pulley and a good fan (the big one). I am running a 180 degree thermostat.

When I am driving it hits 180 on the dot, but when It's stopped or if I let it idle, it doesn't take long before it starts to warm up (200+ in about 10 minutes) If I get going again it will slowly cool back down. It also slowly gets hot in stop and go traffic. It's only happy if it gets a constant flow of air.

The only thing I can think of is when I got the radiator back from the shop, I painted it with high heat black. I thought too much paint on the fins would not allow it to cool properly. I can still see through it though.

Or maybe I just need a new radiator.

Some input would be awesome. It's no fun to drive when I have to worry about overheating!

The engine is in my 1950 Chevy Pickup

Yes that paint may be your problem. Should be very cold in CO this time of year, should run all day and never get hot. I had to add an electric pusher fan on my 46, only because of HOT weather in traffic.

I would like to know more about the electric fans that are available, and how they compare to the standard setup

There are numerous fans avaiable at most parts stores. they all run on 12v usually fed power through a relay. the relay can be powered from several sources--- A/C clutch, Temp switch(newer models) or a toggle switch. most AFTERMARKET fans are "universal" fit and come in several sizes pricing starts about $75 and goes up. Create your own wiring harness, most are designed to "piggy back" an existing system.
******A note of caution*******
Many can be wired as a pusher or puller, depending on which side of the radaitor you mount it on. BE CAREFUL IF THE WIRING IS "REVERSED" YOU CAN CREATE A WORSE OVER HEATING PROBLEM!
I hope this helps, good luck.
Brad

Are you sure you have the engine timing advanced enough?

Yes it might be the paint. What radiator cap do you have? A 180 degree thermostat might be too hot. And last what type of radiator core is in your radaitor? I ask because if it is a cellular type core they are difficult to clean.
Good Luck
Steve

Radiator shops use a special heat-conducting paint. I'd suggest stripping it down, and using a different type of paint. Also, just spray the surface, at an angle. You don't want to coat the entire core with paint, just the part that gets seen from the outside!
Jerry

Can I add an electric fan on the front of my radiator in addition to the belt driven fan?

not sure that would be useful - one might be fightin the other - I'd say either or
how close is your fan to the rad, and is it fairly centered, or down towards the bottom? needs to be quite close otherwise a shroud helps] and somewhat centered

Bill

The fan is very close and in the center. Maybe it would be best to remove the belt fan and replace it with a new electric assembly.

I am wondering if electric offers better cooling?

I am using a 4# radiator cap

That fan should cool it. Try another 180 therm. or test the one in there in a pan of boiling water. It should open fully. I have seen several times where therms. have been defective. If the radiator is in good shape you could run a 7lb cap.

Are you boiling over? Is your gauge correct? I think a 7# cap with a 165 degree thermostat is stock. You surely do not need two fans. The stock fan should be fine.

As a rule, you get more air moving at low speeds with a stock fan than you will with an electic. I would start by getting the paint off the radiator and leave it bare to see what happens. For some reason your not getting either enough air or water moving at idle. Could also be water pump or fan belt problems. Can you see water flowing at idle?

I worked out a similar problem: The valves may be set too tight especially the exhaust valves. When the valves are too tight you will experience temp creep because the exhaust valve is not on the seat long enough to transfer heat. Also with a 180 degree therm the engine heats up to 180 before the radiator gets a wack at cooling and then is behind when it does start to cool. Put in a 160 degree. Recheck your timing and make sure your vacuum advance is working. Someone mentioned the rad paint also. Good luck.

I run a 180 degree stat in my 261 and the temperature never gets over 190. Definately check your valve lash and thermostat before you try anything else. Also check to make sure the lower hose isn't collapsing under the suction of the water pump. It is supposed to have a spring in it.

I have my exhaust set at .014" and my intake is set at .007" Let me know if I should use I different adjustment, or one that would help it cool better.

Also... what it the advantage of a 4 or 7 pound cap with a 160 or 180 degree thermostat? The coolant is not even close to boiling.

the 4# rating should be fine w/ these old rads [even rebuilt] and if you're not blowing a lot of coolant out the overflow when it's 'hot', things are fine - the 7# cap will allow higher pressure before blowing off, which might be useful when it's runnin a bit warm, but running the 7# you're more likely to spring leaks on an old rad - nothing to do w/ boiling, just that the coolant changing temps from rad to block results in rapid temp change expansion

in my experience, the 235's are cold runners, and using a 160 [which allows cooling to start at that lower temp] normally results in a 235 running cold - 180 is what it should have, to keep the temp above that - I agree ya got something wrong someplace if you're having problems w/ a 4# cap and 180 thermostat

are you sure the water pump is pumping well? maybe pumping too fast? maybe you got the wrong size pulley on it?

Bill

The coolant is not even close to boiling.
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I would check the temp of the coolant to see if your gauge is correct. Also be sure you have a 50/50 mix of water and antifreeze ( 1 gallon is enough, any more is too much).
Steve

How do I check the water pump to see if it is pumping well? It has the 6" pulley. I am pretty sure this is the right one.

Axton,you running a 56 235 in an early truck? the problem is typical of the low fan position cause of the low mounted water pump.If ain't radiator paint or phases of the moon,it's the pump location. Get a pump adapter to use a 216 pump,raises the fan about 3-1/2 inches,or go electric fan,or a fan shroud at the least.
The low mounted water pump is driven at slightly less than engine speed,the earlier 216 pump is driven at 1.4 times the crank speed.

Where can I get an adaptor? Who sells them and how much?

Here's the Ebay link Pump adapter
The guy who sells tham visits this site,he goes by Pre 68 Dave.
I have done the conversion 3 times,and in all cases the engine temp stayed normal in heavy traffic.
Be advised,the conversion requires some simple engineering,drilling and tapping two holes in the block.It's easy to do when the front sheetmetal is off,a little harder with just the radiator removed.
If you have the 6-3/4 inch damper pulley,you may want to swap to a larger pulley on the 216 pump,60's-70's Ford 200 6 cylinder has the correct size pulley,about 5 inches in diameter with the correct offset,this keeps the 216 pump spinning at about 1.4 times the crank speed.Although some guys don't worry about the pump speed.
Your stock old fan will be spinning faster,maybe not a good idea,an 18 inch Flex-a-lite normal looking 6 blade fan works out very well,it needs to trimmed at the edges to clear the damper,easily done with a tin snips.Or Flex-a-lite make nylon fans that are easier to deal with.I have a nylon one here already trimmed for the conversion,you can have it for free,just pay me shipping.
If this is more trouble than you need,go for an electric fan if you like your truck to sound like a modern front drive car

I really think my problem is the radiator. Is it possible that not all of the radiator is cooling?

sure it's possible if some of the tubes are plugged, but didn't the rad shop 'boil it out'? 'rod it out'? - and possible that bar-b-q paint doesn't dissapate the heat well enuff - why didn't it have proper paint put on in the shop, or did you just want more shine?
I think Tony might be right about the pump position, which is what I was askin about the fan bein fairly centered - up and down, not side to side

Bill

Axton--

I come to this thread late but I don't think its ur radiator because it's just been rebuilt and if it weren't circulating you would gone above the boiling point based on what you describe. I'd listen to TruckedUp--raise your fan with the adaptor.