Posted by Vaughn [172.68.141.235] on Saturday, May 19, 2018 at 09:35:10 :
In Reply to: Re: Cylinder head update #3 posted by Clint Dixon [172.68.58.86] on Saturday, May 19, 2018 at 06:35:27 :
Well, the thermostat is probably working fine, sounds like it is, if you haven't replaced the water distribution tube, if it were me, that would be the next item to check. If you have good flow of water out the bottom hose outlet of the radiator, then rule that out. When you had the head off, did you check head and block for war page? Did you notice any gray area between cylinders on the block, an indication of leakage? Engines that heat quick and cool slow, are an indication of leakage between cylinders. What head gasket did you use, old style or new? The new paper/copper gasket will only work with block and head in good shape.
I had the same symptoms you're experiencing with the engine, and I had a low area between 5 & 6. To avoid pulling the engine and having the block resurfaced, I used the old style gasket and Otey Pipe Joint Compound to seal the gasket adding an extra amount in the low area. I know, pipe joint compound is not for sealing engine parts, but it can hold 6,000 pounds of pressure per square inch, and that's enough for the old flathead. Now my truck runs 140 to 160 with a 160 thermo depending on outside temp. It can run 160 on a warm day, let it set for 15 minutes, and the engine temp will drop 20 to 30 degrees so I know internally, the engine is sealed. You may need to do the same.
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