My Y block powered ‘54 Country Squire has been running hot on the highway. The rad is from a late 60’s mustang and smaller than a stock ‘54 rad. I had a 14” electric fan mounted on a sheet metal shroud that spaced the fan about an inch from the rad. It ran fine in traffic and at idle but got hot on the highway. I’ve since switched to a 16’ fan directly against the radiator. It doesn’t run as hot on the highway now but still hotter than I’d like, and it doesn’t overheat in traffic. My next step was going to be replacing the he mustang radiator with a stock sized ‘54 rad. However I’m planning to swap the transmission for an AOD with overdrive. Will the lower highway RPM hurt or help my cooling issues?
The lower RPM will absolutely help your temps. Horsepower creates heat. If your foot is in the gas to keep the car moving at highway speed, you're putting a load on the engine, and creating heat. The overdrive will lower that RPM, take some of that load off of the engine, while simultaneously feeding air at highway speed through the radiator.
fans have little or no effect at highway speeds. once you are going about 40 mph the speed of the car is forcing more air in than a fan possibly could. you answered your own question, the radiator is too small. one other thing could be the cause. the lower radiator hose needs to have an anti collapse spring inside it. I have 2 cars that did not have them and ran hot on the freeway. Once I put springs in them the problem went away
Yes, assuming it is properly "caught" at the front, led to and through the radiator, and let out somewhere further back. Even basics like that can get messed up, perhaps by using a smaller radiator and neglecting to block off the opening around the radiator letting most of the air go around it rather than through.
Before changing the radiator do a block check to see if you are getting exhaust gas in the coolant. A lot of the time, this will contribute to running hot. My axiom: runs hot at low speed > exhaust in coolant, runs hot at high speed > radiator plugged up.
Yes what is hot??? Dash gauge hot? Temp gun hot? Boiling over hot? Many think if they install a 180 thermostat in their engine that anything over that is hot. Many think 200-215 is hot. They only real concern should be when you see steam. Steam will not allow the engine to cool.
Thanks everyone, Some more information, the car doesn’t push water or steam, but it can hit 235° on the gauge at 65mph/3500rpm it has a stock rearend but slightly smaller than stock tires, probably about a 3.40 gear. If I swap the AOD in then I’ll likely swap in an 8.8 with 373 gears which will give me a better start in 1st gear and a good highway rpm in overdrive. yes overdrive AOD is redundant but not everyone knows what AOD stands for lol. To mount the rad I added 1/8” plate to the mounting flanges on the sides. As a result there is no space around the rad for air to bypass, all the air that would hit a stock rad is forced through the current rad. Interesting thing, the rear of the hood lifts slightly at speed so the car may be packing air,
Is the 235 degrees gauge hot?? If so, you may be saving alot of work and money if you buy a temp gun. Sounds like you do have trapped air. Consider louvers in your inner fenders.
IMHO, 235 degrees running down the road is too hot. It sounds like you don't have enough radiator to cool that engine. If anything, in my experience, you look for sections of open road where you can run to cool off an engine that is starting to heat up from sitting in traffic where no air is moving. And FWIW, your radiator must be small as hell for a Y block to run hot. I'm not a fan of that particular engine family generally, but credit where its due, they are typically cool running engines.
Get the proper radiator…US Radiators as 4 levels in the copper/brass. IMO an early Mustang is way too small. Fords in some states had a panel above the radiator support and rad top that sealed to the hood with a rubber seal. All air entering the grille was forced thru the radiator or interior air vents. Definitely helps.
I'm thinking that if the rear edge of the hood is rising up at speed, a bigger radiator probably isn't going to help much. For the radiator to functioning correctly, the air has to pass through it. If the hood is lifting at speed, the hot air movement is being restricted and is not being removed from under the hood, so you are reducing the amount of air that can pass through the radiator. You need to add louvers, remove the hood side panels, or figure out a way to get the air already under the hood to exit out from under the hood so more air can pass through the radiator. If you get the air to exit from under the hood better, you may find the cooling problem gone, or you still may need that larger radiator, but until you can get the air to flow freely out from under the hood, you are not going to know.
Most well maintained 54 ford cool fine, even with a larger Y block. The radiator is too small and the fan mount to the radiator might just be impeding the flow. The right radiator and an engine driven fan (don’t know what they used, but the oem 3 and 4 blade ones weren’t that great) you should be good. Running a 55-57 bird with the hood open (front hinges) is a common “parade” deal for overheating at idle. But over 60 the back of the hood rises and starts to block the windshield. Some guys put a strap on them. Fixing the radiator is a better idea. Before you buy the radiator see if the cooler for the transmission will be ok with the AOD. Early Fordo’s were air cooled, so that may be an additional item either not available or not adequate. Heat will kill the AOD.
When I purchased a new U.S. Radiator 9 years ago I asked to the trans cooler in the lower tank even though I had an air cooled Ford-O… when I changed transmission to a 62 Cruise-O it was ready. I also use a plastic fan shroud from Southwest Thunderbirds and a 6 blade fan. The smaller Mustang 289 water pump pulley made the biggest change. No overheating at 90* plus with the AC on. From when these cars were new the only real change is the formula for gasoline…. I blame it for most of our problems but with the proper fix, band aid to some, our Fords will perform perfectly. My temp is never over 180. In the photo you can see the stock upper hood seal, fan shroud, 6 blade fan, coolant recovery bottle, and smaller water pump pulley.
Back to this, You said you filled the spaces beside the radiator but did you put the panel back on above the radiator that seals the radiator support to the hood? Looking at a batch of 54 Fords on the net that were mostly in fo sale adds it looks like it is real common to forget to put the panel back on that goes between the hood latch panel and the radiator especially if the radiator is swapped. If that is missing a lot of air is going to go over the core support rather than though the radiator. The sweet glass top that is in Germany having all the pieces still in place
Have you got one of those terrible aluminium/stainless plates that directs the fan air by blocking off half the radiator?
This usually turns out to be the culprit. Getting hot air to exit is harder than you would think on some old cars. My 49 Buick drove me crazy. My 49 Chevrolet Tin Woody, I never did fix. Took it to the auction, as i was tired of it anyway.
Here are some pics. I think I’ve got all the sheet metal installed. The car runs at 180-190° at any speed 50mph and below. It only gets hot at 60mph and above. I can drive on country roads all day long and idle till I run out of gas and won’t get about 190°.
The core of that radiator is really small it only looks like a couple inches on either side but that's a lot fewer cubic inches of cooling area.
A few thoughts: Some electric fans will turn backwards and block airflow at highway speeds. I knew someone who had that issue on a mid-60's GM car. Manually switching the fan on made his big block run cold. I didn't see mention of how your fan is controlled. If the fan is running at highway speeds, does it still get hot? If the first bullet isn't it, does taking the hood off and going down the highway with no hood solve your issue? If so it's an issue of under hood air evacuation. When's the last time your engine and rad were flushed? I've used off the shelf rad flush products to resolve heating issues several times with great success. After investigating the above, if there was no relief I would look to the rad. I know a few people that have run those Mustang rads and they're often just not big enough.
That radiator looks really small for a V8 motor. The air gap between the sheet metal piece at the hood latch and the front and sides of the radiator is allowing a huge amount of air to bypass the radiator, and that bypass air could be what is raising up the back of the hood. The car was originally designed to flow the amount of air that could pass through the radiator to exit from under the hood, if you have a lot of extra air that does not pass through the radiator entering that air space, it could reduce how much air cab pass through the radiator because it can overwhelm the exit flow. Generally any space around the front, sides, above, or below the radiator of 1/4" or more is increasing how much air will go around the radiator rather then pass through the radiator. The air hitting the front of your car rolling down the highway at 60, will take the easiest path around your car. Going around the radiator is much easier then going through the radiator. The goal is to get all the air that enters the grille area to pass through the radiator, that means blocking off as much area that can allow the air to go around the radiator is much better.
Only gets hot at 60 mph+, I would look at the tune up, running lean at those speeds, or need for more spark advance. And do you have an anti collapse spring in the lower hose?
Sounds like the consensus is that I need the proper rad. I was planning to do that anyway. once I Get the new radiator installed I’ll bend up some sheet metal to block off the air that is passing over the rad. I do t think there is a problem with the tuneup, the car runs great and the plugs look about perfect after a long run.
is there an anti collapse spring in the lower hose? you can tell by squeezing it with your hand. (this is the third time this has been asked)
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