I know this has been a very good topic in the past for flathead overheating. I am having the same issue but I would like your input on these copper tube sleeves which have a 3/4 opening at one end and 1 1/2 inche at the other end to slow down the water flow to the radiator I will have them installed inside the hoses and closest to the radiator neck and hopefully get the temperature down. I will be using the Dextcool 50 / 50 with distilled water. I do not have thermostats in my hoses at this time. Let me know Thanks Frenchy
Gee in the old days LOL we just drilled a hole in a freeze plug or used a washer. But that should work OK also. Personally on the street I always used thermostats. Do run a block check to look for combustion gases to make sure that is not the prob. In the 60s I ran a 296 flattie and with a good block it ran 180-190 in mid summer here inPhoenix with 180 stats.
Adequate radiator checked for flow and cleaned if necessary. Air deflectors in place to insure all air flows through radiator core. Even in a radiator shell some deflection may be necessary of the rad sits behind the grille opening ala 32 Ford. Thermostats 180 degree. Water jackets in block cleaned. Water pumps working correctly. Timing correctly set. 50/50 Coolant/water(distilled prefered) Mechanical fan centered in radiator core spaced at 3/4"-1". Electric fan mounted to rear of radiator centered in core with thermostatic switch and manual override. The above are the keys to cool running flatheads.
Brand new engine rebuilt with new Skip Haney water pumps new pistons new Ron Davis radiator custom build etc ... Thanks Frenchy
Install decent thermostats with a high flow capacity, Supposedly Prestone makes a good one. Use 170 to 180 deg. Slowing the flow down does not help cooling, just the opposite.
im gnna have to agree with installing thermostats. my flathead runs 180-190 here in vegas even during the summer heat..the highest ive seen mine go is 220 and that was stuck at a red light.
As someone above said, timing, timing, timing. Good proper advance curve cures more heating problems than anything else. What ya running for a distributor and ignition ??? As a problem solving hamb-er aid ship me the system and i will check and curve for no charge. Have fixed a ton of them just by making the advance function properly. New Mallory odds are 90 to 1 the advance curve is like a chevrolet every time...... www.bubbashotrodshop.com Glad to help .......
I appreciate everyone input. The engine is a V12 Lincoln. The distributor was timed on the Sun machine and the advance was also adjusted on the Sun. I have a pair of the original thermostat which is to be installed right after it leave the head . I will installed them first and see what will happen. Most of the other V12 I have build in the past were installed in cars that had the original radiator and we never installed thermostat in any of them and never had overheating issues possibly because I have a smaller radiator in my 32. Thanks again Frenchy
Frenchy, Boil your thermostats on the stove first to make sure they cycle open and closed before you install them Sometimes it will take a good boiling to get a sticky stat to open. And you don't want to do this in your fresh engine (boil it)
I have installed the copper sleeves in my hoses which are the ones shown at the beginning of my post. Where is the proper placement for them. Better at the top of the hoses close to the radiator or at the bottom close to the heads. Let me know Thanks Frenchy
Is Dextcool that pinkish stuff that GM uses? The stuff that chunks up if it gets any air in it? I wouldn't go that way if I was you.
I wouldn't run any antifreeze or glycol-based "coolant" unless you're concerned about freezing. Straight water, a wetting agent, and a corrosion inhibitor. If freezing, mix in no more antifreeze than required for the temperature protection you require. I run T-stats in all my engines - all drilled with at least one or two "burp holes". Timing, as mentioned, is critical on a flathead. They can use a tiny bit more initial advance (from stock 4 to about 6) which seems to help a lot.
I just got my flattie on the road last week. I was having the exact opposite problem, my flattie wouldnt run over 140. And that was in traffic with no fan. Seriously. Well, come to find out, my t-stat's had lodged themselves in the corner of the rad hose. I put a hose clamp about a 1/4 inch above the cylinder head to hold the t-stat in place, then I put the fan back on. My car is running 180 all day. Ive yet to see it climb at all. I have the speedway pumps on my 59A with a converted Model A re-pop radiator.
Well it has been a year since I had my car on the road. So far no problem the temperature is staying at 170 with the electric fan on here in Phoenix keeping in mind that we had temperature up to 112 and the radiator stayed at 170 no problems. Thanks Frenchy
I live in Southern GA and i just purchased a 50 custom deluxe... i dont have any fancy tools or anything and i read that an effective way to ck to see if the water jacket is broke on the block is to pull the water pump belts and start her up and look for bubbles in the radiator. i was having the same problem with an overheating flattie, i looked and i had no thermostats in it, so i drained the radiator, flushed it with a hose, flushed the block with the hose and ****oned her back up with 160 thermostats and wetter water. the theory behind the thermostats or washers for that matter is that the flathead needs resistance, the liquid needs a chance to soak in the heatfrom the block back to the radiator. im no genius just a shady tree hobbyist mechanic, but the flattie runs like a champ now 150-170
Wait before you stick those stupid pipe fitting in your radiator hoses why don't you just determine what the operating temperature is after you have the engine in operation. This is like the question "how hot is hot?", if you do not establish a base line it is difficult to speculate if restrictors are necessary? If you didn't have thermostats and your engine temp range was ok you shouldn't need them now. The better coolant is just plain water or water with a wetting conditioner for summer use. .
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