Overheating Flathead

M

millcroft

Junior Member
I had a 53 Flathead rebuilt for my 40 Ford Coupe but it runs very hot except in winter. I am seeking help!!
I had the heads cooked out and shaved, installed new DRAKE water pumps, installed a new aluminum radiator, installed an expansion tank, reset the timing numerous times, but it still boils out the water.Have 160% thermostats,also.

Could anyone suggest what to do next.

I have rebuilt five flatheads in the past and did not have this problem.
 
Are you leaving enough room in the radiator for the water to expand when it is hot?

How hot is hot to you? Temperature degrees?
 
Not sure if I can help but, I do have some questions/suggestions. First, what do you consider "very hot"? If the Flathead is running at 180 or a bit closer to 200 (in the summer), that's not too bad... if the 160 stats you are using are the "new" type, I'd pull them out, as they are too restrictive. I'm also not a big fan of aluminum radiators (but that's just me), what pressure cap are you using? I run Skip Haney rebuilt water pumps on most of our Flatheads, here in central Florida the temp hovers around the low to mid 90's and our Flatheads, without thermostats and with stock radiators with the suggested pressure caps and Skips pumps run a steady 180 to 190 on the highway and in traffic. The only time the Flatheads get warmer is if and when I get stuck at one of the millennium stop lights here... One more question, are you running a stock distributor or an electronic one? An electronic distributor should let the Flathead run a bit cooler. Sorry if I'm not much help, but the things I've done have helped our Flatheads run cooler.
 
welcome to the 'Barn....got pics??...lol....what carb/carbs??....hopefully the brain trust here at the 'Barn can help you sort out your flathead.....what gauges are you using??....checked the temps with an infrared temp. gun?....Mike
 
The Drake pumps are high volume, and the thermostats (if the conventional type) are low volume. Remove the thermos, they are blocking the flow. Thermos are solely there for a quick warmup.
If you still have problems, remove the water pumps and put a high pressure water-blasting wand up into the water jackets. You'll be surprised how much rust, casting sand, core wire and other odd objects comes out of the water jackets.
 
Bassman is right. Henry did not do a good job of removing all the casting sand from the water jackets. Many flatheads have sand packed into the back of the block. The only way to get it out is to use sharp probes through the water jacket holes in the block surface. When I had my two flatheads built, the builder took out about a quart of sand out of each one. He probed through the water jacket holes and then rolled the block back and forth on a sheet of plywood till all the sand came out. Both of the engines ran cool after he was done.
 
add some "water wetter" different brands about the same stuff-personally I like the one by Lucas--seems to take about 10/15 degrees out of my flatheads
 
Did you check for exhaust gases in the coolant?
Timing. ?? Try 7 degrees advance and see if that helps
 
My blown 276 could not idle or perform in parades without boiling over. Griffin aluminum radiator with a fan shroud, electric fan and no thermostats now will sit in my drive way and idle with fan going on and off to keep everything in check.

Just the way I did it not necessarily THE way.

Fourdy
 
where is teh fan in relation to the center of the radiator? if it is way up high and not drawing much air through it, that will contrubute...
 
alan said:
add some "water wetter" different brands about the same stuff-personally I like the one by Lucas--seems to take about 10/15 degrees out of my flatheads
Click to expand...

Purple Ice water wetter worked for me too. Some people reckon it doesn't work, but I had to take it out of my system because it was running too cool. I have Drake pumps and no thermos and it sits just right now.
 
Thanks!
The motor was rebuilt and was supposed to have been cooked out prior to magnafluxing but maybe they did not follow the normal procedure.
 
Millcroft. Please let us know how you make out. I to have a overheating problem in my flathead. There were no thermostats in it when I got it, but, I heard that doesn't allow the radiator cool the fluid. Some say the coolest runs through the radiator too fast to cool. Anyway, I installed two 160 degree thermostats. I also drilled 6 quarter inch holes in the flanges of the thermostats. On normal days it works fine. However, yesterday and today it' s been in the 90s and the car tends to get very hot. Maybe the weather is just too much? - Dick
 
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