I have a ‘36 LB Flathead I installed in my ‘29 coupe over the winter. I had the engine torn down and there were no ubstructions in the block, nothing in the heads. Nice clean engine. I took my ‘29 radiator to a shop and had them look it over. They said it was a super nice radiator. I had them add a port to the top and bottom tanks. Today while driving them temp went up to 210. It did not get any hotter but it was only 82 degrees. I stopped at a gas station to get smokes and let it idle and when I got back in the temp was 220+. It calmed down immediately to 185 driving and began to go up. I am running no thermostats at the moment. Should I install thermostats? Is my A radiator to small? Any thoughts? I don’t want a boil over every time I drive it this summer.
Yes..... If you don't run a thermostat nothing is regulating the flow of coolant and the radiator can't act as a heat exchanger and cool the water.
With my hopped up bangers a stock Model A, two row radiator isn't enough cooling on a hot day or at idle. I'm thinking you are going to need more radiator. Sent from my XT1585 using The H.A.M.B. mobile app
If you don't have a thermostat you don't know if the radiator is large enough.... Then if it runs warm it can be airflow .... I've seen cars with big radiators run hot without a proper fan or shroud.... Just putting in a bigger radiator doesn't always fix the problem
You have two issues going on here. One is you need to run thermostats. Henry Ford was cheap, and his Ford flatheads ran thermostats. If thermostats weren't needed Henry Ford certainly wouldn't have put them in his flathead engines. Two is that a stock Model A radiator won't cool your 1936 flathead engine. The Model A radiator was designed for a 4 cylinder engine and just won't effectively cool a flathead V8.
My problem with the New radiators is the bottom take is too tall and you can see it. A stock a bottom tank is about 1 inch if that.
Ok, I'll bite, if the new radiator is the same size as the old one and the old one is clean and bitchen where is the difference gonna be, I had a couple radiators built for a 1947 Peterbilt, mind you it came out new with a Hallscott or a Cummins of small horse power, I had to make a second new radiator for it because of some assholes inattention to his driving and this one came from Radiator Supply house in Oregon and showed up with one less row of tubes, Vince told me that by the time air got to the last row of tubes it was too hot to do anything, he might just be right as I have a Cummins of larger horsepower in it now and can't get it hot.
Same problem with my girlfriend - she's kinda petite - but has large projectiles that poke out........
Well, crap, man, folks have told you the answer. Continue to "look right" or run right. Only you can decide. Ben
U S radiator makes good ones. You can get different heights and the lower tanks are compact. They moved the outlets in 1/2 inch to match water pumps for me. I have a 276 and the fan is not real close to the core but it never goes over the 170 thermostat temperature on hot days. ford-1928-1953-car-1928-29-v8-flathead-radiator.html John
You will need stats any way, so try a pair of 180s. I had 160s in a 52 Ford with 8BA & it ran hot. Switched to 180s & it ran cooler.Kept coolant in the rad longer. New rad or not you need stats. My .02 cents, or nonsense.............
You never said it actually boiled over and 210/ 185 sound like perfectly normal temps? Some thermostats will help it regulate I think that’s all you need. If a stock model A radiator can cool a sbc it can cool a Flathead. worse case you could find an AA radiator they are twice as thick as an A but look the same other wise
I took it to the gas station and let it idle when I went in for smokes. When I came out it was at 230. I drove away and it went down quickly but when I got home and let it cool down I was about a gallon low on coolant. I went back to the gas station today and saw my trail of coolant. I bought some thermostats today and some water wetter. I’ll see if that makes a difference.
With a shot, if it wasn’t a whole gallon low I’d say maybe you just have more in it than it wants. Wouldn’t be the first car to do it. hopefully the thermostats do the trick, you’re close.
If you don’t have an over flow tank, leave the water down 1” in the top tank. I run a 7 psi tank and have a US radiator and it only pucked coolant when I forgot to leave the tank low.... That’s the way they are meant to be run...
No overflow tank. I do leave the coolant low as I found out ten years ago when I first bought the car. It pucked because I had it filled right to the top but found its sweet spot and I never had to do a thing after that. But that was with the banger.
Drove it around a bit and it got up to 200-205 so I brought it back home. Dang. I do not have the cash for a new radiator at the moment.
Thats why A V8 ran 32 radiators and grill shells , they didn’t have to solder necks in by the radiator shop, just bolt on and go, and it cooled them.
My fan is from a ‘46. It is practically the same diameter as my radiator so a shroud would be almost impossible.
No don’t drop the water in your radiator. Along with a pressurized radiator cap install a brake residual valve onto your overflow hose. Yes I said (brake). It runs at 2 lb and will keep your radiator from losing your needed coolant and the pressurized system will keep it cooler. I run them on all my Flathead’s. https://www.jegs.com/i/JEGS/555/631030/10002/-1
T stats for sure. I knew some flathead racers that used washers that slowed the flow a long time ago. I don't remember what they are called now but you can still buy them in different sizes. Some drag racers use them. I probably would not use them in a street car. Last flathead I drove on a regular basis was in the very early '70s. It was a Merc hardtop. Someone who owned it before I did put dual temp gauges in it. I had a stat stick on the pass side once and pulled it out (to get home) and kept an eye on it. The driver side temp gauge maintained a better temp than the pass side.
I run the same thing on my stock 34 radiator with Skips pumps and no thermostats on the 59AB in my 34. Never, ever gets hot. Has the stock cap too I made a thicker gasket for to help with puking. My Brother has a 29 roadster AV8 with a 1934 flathead V8, he used a stock 32 radiator cut down to 28-29 height (new core). Stock cap. Pressure valve. Runs a 33-34 fan with the blades shortened to clear. No thermostats. Skips Pumps. Never runs hot.