1937 buick rat rod

I have a 1937 buick rat rod has a small 305 in it and it is running hot like 210 most the time somtimes it gets alot hotter. the way i got my car rigged right now it is impossable to get a larger radiator and im running a small radiator off some small forign car. is there a possibility of rigging somthing up to run 2 radiators? what elce can i do to get it to run cooler? I got a fan on it and i changed out the thermostat

How about two fans?

were would i put the other fan?

because hondas are throw away cars and a car that is over 70 years old diservies some respect.

Does it run hot all of the time, only at idle/slow speed, or only at highway speeds?

There’s several possibilities but was curious about the exact symptoms first.
As usual, ignore the poster who continues to try and mangle every post on the forum. I always prefer the odd stuff so a 37 Buick is darned cool IMHO due to it being so rare.

are you certain the used radiator was in good condition?

you may be restricted by overall size, but if it wasn’t in good shape when you put it in; you’re killing cooling from the start with a bad radiator.

you mention the fan. an original fan? the original fans were just a plain two blade, bent sheet metal fan (very inefficient.) find a modern fan blade. they are much more efficient. the trick will be to find one that FITS!

How about you let him worry about what he wants to do with his car and you just mind your own business. You’ve been preaching this very idea all evening.

More info needed:

  1. Explain in more detail what temps you see under various conditions. For example, is the temp affected by road speed? Does it spike up to >210 only when sitting still and idling?

  2. What temp thermostat do you have in there now?

  3. Carbureted engine?

  4. Is the 305 basically stock?

  5. Tell us more about where you got the donor rad from, or failing that, what are the dimensions of it?

  6. If your temp problem is while idling only, describe your fan including; diameter, flow rate, pusher or puller, how it’s coupled to the rad and on which side.

  7. Any other components in the air stream for the rad (e.g. A/C, transcooler etc)?

Don’t overlook ignition timing. Overly advanced ignition timing can really make an engine run hot.

You need a larger radiator. I doubt the current one is any more than a 2-core, probably a single core. If you know the car it came out of, contact these people, and request a 4-core version : http://www.americanradiator.com/. Or talk to them about your current set-up. They may be able to help. They can actually build a radiator to your specs.

i think its a radiator off a honda civic i need to go mesure it but looks new and its really small, everyone tells me its small for a V8. I got the coolest temp thermostat and im not sure about the ignition at all, it seems to get hottest after a burst of gas like getting on a on ramp or sitting idleing after its been running. I can let it idle for hours but if I run the motor on the road for a bit then it over heats. ill tell you what it is. its 1937 buick with a S10 sub frame and a camero rear end with a chevy motor and criager rims tubed in the back. I just blew the carberator it was a Q-jet. and i just perchased a 600 edlebrock carb, havnt hooked it up yet but im thinking it might even make it run hotter. im gonna post a picture this is an old picture before i finished the hood and painted it black

I do not know what the stated specs are on the Civic radiator but it is probably far less than the standard radiator for the 305. Radiators are rated in BTUs dispersed and the radiator you have is simply not going to get rid of that much heat.
Another problem you have is the narrow frontal cross-section of the car.

Many GM cars use a plastic airdam underneath the lower radiator support. This forces air up and through the radiator. When these airdams get broken off (usually on curbs or critters) the engine will overheat while on the road; sometimes as much as 30-40 degrees. Idling and stop/go driving will not be affected.

I think you need a larger radiator along with fabricating an airdam to go under the car. Most dams are about 3-4 inches wide and 3 feet long. A strip of 1/8" aluminum would work.

Try a different radiator and airdam first. If any overheating problems continue I would rig up a canister for additional coolant rather than use 2 radiators. A 1 and 1/2 or 2 gallon canister with a pair of heater hose fittings or radiator hose fittings should do it. A 5" diameter piece of pipe about 2 feet long with end caps welded on would work as a coolant canister.

My feeling is that a proper radiator and airdam should be sufficient.

Because of the pointed nose, the openings on the sides of the engine are restricting your air flow. Maybe you need some gills to cover the openings. Try an electric fan. OK had a good suggestion if you can get an airdam right under the radiator.

You don’t have a problem; or, why do you think you have a problem? Cooling systems since, about, the 1950’s, consistently, and quite safely, run at 220F degrees at 15 psi. They don’t boil over until 265F degrees.
Cooling systems before the 1950’s ran at lower pressures, and lower temperatures.
Your 'rod has the more modern cooling system and engine; so, it can run at modern temperatures and pressures. Don’t mistake the opening temperature of thermostats to the normal operating temperature (220F degrees) of the cooling system.

My first thought was similar to yours, that in the very early 1970s and in response to the clean air act manufactureres raised thermostats to 185F and operating temperatures accordingly.

However I do think it would be wise to get a radiator capable of disspating the heat from a 305 V8 rather than keep running with one designed to cool a 1600cc I4. In addition to having a much larger engine, that car has a huge frontal area, does not have the aerodynamics of a new Honda and overheating on the highway in the summer would not be a surprize. I’d want to get a proper sized radiator before that event happens.

The poster who provided the link to the aftermarket radiators for classic cars was, I think, the one with the best idea.


By the way, if your moniker is a reference to military rank, thanks for serving.

Some small cars have two radiators, side by side, each with an electric cooling fan. One radiator cools the engine, and the other radiator cools, either the automatic transmission fluid, or the A/C (condenser).

thanks for all the replies i really do need a bigger radiator but right now money is the problem, to get a custom radiator is really expensive and also space is critical because the power stearing lines are routed right underneath this radiator, so i would have to rout all new lines could be a pain in the ass. some one told me I could run the motor without a thermostat at all and it would stay cooler anyone know anything about that?. Also thanks for the complament for the military, yes I am a vet

At the temp your rod is running, the thermostat is always open, anyways. Removing it will do no good. HEre’s another source for radiators that will fit the '37 Buick, and can be big enough to handle a SMC. http://www.walkerradiatorworks.com/radiators.cfm. But, they don’t come cheap.

The Civic radiator just does not have the capacity to ger rid of the heat generated by a much larger engine. Removing the thermostat will not help.

The same kind of problems would occur on a home A/C unit in regards to capacity. Drop a 4 ton compressor into a 1 and 1/2 ton chassis and problems will develop.