Im in no position to talk technicalities, but when I owned my '50 shoebox, I had the same problem with the Flatty (Stock 239ci, non-OD) running hot. I would run it around 70mph on the highway, and the temp would climb to the 200's. However, 3 days after getting the flatty back on the road after 30 years, before starting the 400-mile (round) trip to Billetproof, I filled er up with some Marvel Mystery Oil. I was running a VERY STEADY 180 degrees going 75-80mph on the highway the entire day. Keep in mind that was without and OD tranny also. People thought I was Nuckin' Futz, but I didnt have ANY problems that entire trip. I wouldn't hesitate to do it again....If I still owned the car.
There is a difference between the pipe and hose thing and a closed system like in a car. If the water in the cooling system is flowing really fast, it won't spend the necessary time in the radiator to get cooled off again. Its a simple idea, the water has less exposure time. When the water gets back to the engine, it WILL NOT absorb the same amount of heat. Its fluid mechanics 101, heat flows from hotter to colder. If the difference between "hot" and "cold" is smaller fewer BTUs of heat can flow from hot to cold. Heat transfer slows to a stop when hot and cold reach a median temperature. I know an old mechanic who used to dirt track race, and he had a few flat heads. He started with no thermostats, and did overheat. He asked around and tried putting washers into the t-stat necks and it helped. The pipe and hose experiment is inaccurate. The water that comes out of the hose is cold to the touch. Exposure time to cool the water off again is not considered because the system is total loss. And of course, if the pipe has a trickle of water flowing through it, the water will be unable to cool the whole pipe. Personally, I think a 2 core aluminum radiator should be sufficient. We have 3 vintage modifieds. My dad has a 1 core in his mod, he seldom uses his electric fan. (the radiator is what the local B-mod, and A-mod guys use). I have a vintage mod with a 2 core aluminum, half the fins are bent over and it has some silicone on the bottom. I paid $20 for it to use as a mock up and have had it in use for three years. I don't have to use my electric fan either. The last car is a '74 Supermod, and it has a brass radiator. The flex fan on it is barely adequate to keep it cool. It runs HOT, and its a 4 row. Pull, the plugs. If they're ghost white the mixture is too lean. I think we've established the timing is close, but If not it try turning up the advance. Pull the T-stats and try some thick washers. I have personally had gauges that weren't accurate, so either buy a $20 temp gun or hook up another gauge just the check the accuracy of what you have. You might have to consider a new radiator but I doubt it. Adam
My T used to run very hot, 220 in town. Could hardly drive it on the highway. Tried the usual stuff to fix it. New water pumps, cleaned the radiator and changed the distributor to a electronic Mallory . It got a little better, but still ran hot. The only thing left was the carb, I fattened up the jets now she runs at 190 all day long. I only have a three speed trans and the radiator is a bit small. You just need to check one thing at a time , sooner or later you will get it fixed.
NOOOOO!!!!!! My bad for not making that clear in my first post I added it to the mix of oil that was already in the Flatty. It was already beginning to run low, so I filled it up with the MMO.
Let me throw this into the mix. Are you sure your fan is pulling air? I only ask because I once wired one wrong by mistake. Was baffled with overheating. One day, friend was sitting on a crate in front of car while it was ilding and smoking. I suddenly noticed his smoke being pushed away from the car. Simple wire reverse and cured the overheat. man did I feel stupid. As far as the flow discussion, back in my racing days, it was common practice to remove every other impeller blade from the water pumps to slow the flow of water. that and two pennies pounded into each block to restrict water flow to the intake. the standard joke at the time was that each blown flathead was worth at least 2 cents.
don't run without stats, it f***s up the flow rate which affects rate of heat transfer. A 16# cap is not helping or hurting the temp issue, it only raises the boiling point which is why you don't boil over, but 7# cap is much safer. Once you get this fixed, change to the 7# cap. No one suggested checking the flow rate of your fan and the direction of flow. I assume it is pushing air past the rad., not pulling. I am running basicly the identical motor as you in my closed hood '50. I am running a fan rated at 2800 cfm it was recommended to run atleast 2400. I have 180 stats., and a walker radiator. I also run air conditioning and the flatty runs at 185 to 190 on hot days with a/c running. I suggest your rad is too small and check the flow on your fan.
Thanks for the Suggestion. Man I wish it was that simple. Its definitely a puller thou. I'll just have to keep trying.
I'm leaning toward a radiator issue. I had an issue with a small block Chevy in my 34 sedan where the thing was running 190 to 235 degrees. I put in a Walker Cobra and now it stays right at 180 regardless of speed. I just wish I knew for certain that this would correct the problem before I drop $700.00
This subject has been debated a lot over at Fordbarn. For those who believe water can run too fast through the system.... Skip's waterpumps are regarded as the Holy Grail of waterpumps. They flow 105-110 gallons in testing and are the cure for many an overheating flattie. Compare that to Fords original pumps which flow 55 gallons. They are therefore flowing twice as much as Ford pumps. Why then, if coolant should not flow fast, are Skips pumps the be all and end all? Because slowing coolant down is a fallacy, that's why. As I mentioned earlier, I run Drakes pumps, which while not flowing as much as Skips, are still flowing way more than Ford pumps. I cannot get my temp above 170, and this with a little Mustang radiator. I might have to slow my coolant flow to RAISE the temp, not cool it.
Ditch that electric fan, run the stock mechainical if possible if not make sure its pulling enough or or pushing which ever you have and make sure it is has an addiquit fan shroud cuz that fan wont do a thing without it. Dont run the thermostats and if you must run a 160 and make sure that it is properly installed. ive seen quite a few that have wiggled there way out and got cocked eyed in the hoses. flush the entire cooing system. Cat used to make a good coolant flush that worked with aluminum raditors not sure if they still do. Otherwise just use water. And like everyone else said check the timing. Do a leak down test or compression check to make sure you head gaskets are in good shape and not blown out. I would also recommend you pull the heads off make sure the head gaskets arent on backwards and all the visable water jacket passages are open. I dont run thermostats, a piece of crap stock raditor, a 4lb cap and a stock fan and my 41 ford never exceeds 190. Good luck thats a nice car and i wouldnt run that thing much longer like that. Flatheads dont like to run hot and youll kill it pretty quick at that temp.
Try removing that ring around your cooling fan, and replace it with a rectangular shroud that pulls the air through most of the radiator fins for more efficient cooling.
I agree with you 100%. Some people get a thought in their head and have thought wrong for years and they will not change their minds. You can not have too much flow and you can not have too big of a radiator.
Thanks Bruce--- I'm using a Mallory Unilte for a Chevy which I had Bubba convert. I got the advance Cranked just below ping. (Although I will again check advance at 2500rpm to make sure its ALL IN.)
Some thought on thermostats...not only are they designed to bring the engine up to temp, they are designed to regulate temps. When the thermostat gets a slug of cold water, it will close enough to slow the flow, when the coolant is hot...the thermostat will open wide and not impede the flow. I still say that this problem doesn't originate in the cooling system, the engine is exposed and able to shed heat without the hood, there's got to be a reason the engine builds heat and can't get rid of it. Timing, fatter carb, pluggage in the cooling passages, head gaskets...I'd really like to know what the solution is, can the op let us know?
Overheated flatties has been a common subject here. I have heard that the blocks get lots of sediment in the cooling passageways over the years. Even from the factory, sand from the casting process may have been left behind. Lots of work, but it may be worth pulling the motor and cleaning out the cooling passages. One old mechanic said he used a piece of rebar both manually and in a drill. Another said he used a piece of cable from a bicycle lock, chucked up in a drill.
The guy says he used nos thermostats and a 16lbs cap . On the bottom of page one someone posted an article on thermostats that states that old style non pressurized thermostats dont work in pressurized systems. Are they the old bellows type that your useing?
I'm running a flattie in an A PK. 3:27 gear I have a two core aluminum radiator I am running 180* stats. My total timing is 24* all in at 2,000RPM. I, running two 94's with #50 main jets, a 31/2 PV rear and a 71/2PV front. Run 180* around town and might get to 190 on hwy speeds. Also, you need to add an overflow tank and a better fan shroud. PS as you change things, only do one thing and test run before the next. If you have to pull the heads, check your spark plug thread length. May be causing the miss above 200*. Butch
I realy don,t understand having the advance to 2500 rpm. My car has 2.78 gears 205/75/15 and setup to crusie at 55mph at 2000 rpm. I have stock dist 8ba and run 190degs at 55 mph. When i was haveing overheating problems with of without termstats same problem. The rad with 1 inch tubes that must be some new one. I would remove the fan and get stock dist. Then go for the big Bucks $700. if not fixed.
This one would idle all day in 90* weather using an original unpressurized 32 radiator, 180* thermostats and a 49 Ford mechanical fan. It does have an old Mallory centrifugal advance dist. No modern theories or old wives tales...just old Ford parts.
WELL --Went back to 7 lb. cap. I pulled out the thermostats and found little change. Slightly longer to reach 180* but still climbed after that to 210* with normal driving. So Then -- I put in restrictors with a 1/2" hole and it took much longer to get up to the 210* area. Things got a liitle better. I was thinking that my electric "puller" fan isn't efficient enough, but at 40-55 mph I don't see the need for any fan. Back to the drawing board.
I don't see how restricting flow with either thermostats or washers could possibly make an engine run cooler. The physics doesn't make sense. Restricting flow is to keep the engine temp high enough.
The right amount of flow restriction keeps hot water in radiator long enough for fan & wind to do its job of removing heat before sending cooler water back to engine.
I'm missing the front pulley sheeve that would run the fan. Had to trim it off for clearance. Can't run it off the alternater- Too High.
Lots of great info and theories here... My situation was not a flattie, but same problems, as I had overheating issues on a sbc 283.... Messed around with a lot of the above, but turned out to be simple lack of air flow thru the radiator.....after much frustration, I put in a good SHROUDED electric fan...and all my problems went away... Just a suggestion to consider.... Good luck, and yes...one awesome ride! Cheers....
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