Ford 841 overheating

Last Ford question from me for the night, the tractor heats up real quick and runs at about 215 deg (according to calibrated kitchen thermometer in the top of the radiator.) Is that usual? I have a 160 deg t stat in there (new just 20 hours ago,) (w kitchen thermometer I see the coolant start flowing at about 160 like it should.) would swapping that out for a lower temperature do much for the running temperature? I’ve flushed it a couple of times, once w vinegar, another time with flush product from the store. Even took both the freeze plugs out to try and get water flushing out every which way. Hose in the top, flowed out easily through the bottom and out plug holes. The radiator is relatively new, nice and clean, hoses are all good, doesn’t lose coolant. I had the head off and had it machined, new gasket. The water passages are rusty, but from what I could see, seemed like plenty of space for water to flow everywhere. I had the pump off, rusty, but looks indestructible. Not sure if that’s just how hot it’s supposed to be or if there’s anything else I ought to do.

Also, the tractor has combination intake and exhaust manifold; there’s cracks at the mounting bolt holes between the two outside exhaust ports and the intake ports. Cracks are up and down, not from port to port. Is that a big deal? If so, think I’ll have any luck fixing that, or would you guess I have to (or can) get a new one?

Thank You

That is a little hot. And no, a cooler thermostat won't help.

How is the airflow through the radiator? Is there a fan shroud? The air should be hot coming through the radiator. If the air is cool, it is not carrying away the heat. Either the air is not flowing through the radiator, or the coolant is not moving through the radiator to be cooled.

But, sounds like you have covered all the bases. As long as it isn't loosing coolant or boiling over, and you have a 50-50 mix of anti freeze and water, the ignition timing is correct, I would just keep an eye on it. At 215 that is concerning but not destructive.

The manifold cracks sound harmless as long as there are no vacuum leaks or major exhaust leaks.

Rick........yer cracked cast iron manifold could be a problem. With the engine running at idle, squirt some WD-40 at the cracks. Iff'n it changes, ya gotta BAD manifold. Buy a NEW one. While some cast iron kenn be BRAIZED, it takes EXPERIENCED welder to due it. Then ya gotta gitter "milled" flat again. As fer flushing yer radiator, thattza goot thang but won't cure yer over heating. Me? I'd just filler with 50/50 anti-freeze, putta 7-lb cap on and runner like ya stole it. (orignal cap was 4-lbs)........the cool Dell

Since you asked 3 question on 3 posts I'll see if I can address them all here.
#1 get your timing problem fixed because it can and will effect the engine temp big time. Make sure the distributor advance is as it should be and also that the distributor bushings are good and that the points plate does not move in an incorrect way.
#2 compression should most likely be around 125-150 on a real good engine.
As for over heating that can be a number of problems like timing. Clogged radiator which some times has to be rodded out to fix. Or even the manifold problem you have. My 841 ran hot years ago till we had the engine rebuild and we replaced the radiator

The manifold was cast with gaps at the bolt hole between intake and exhaust. Late ignition timing will lead to overheating (see OLD's Post) as well as too lean. Lean will lead to burnt #4 valve; ask me how I know!! How hard are you working it when it gets hot?

My Ford 4000 4cyl ran hot til I put a higher
pressure radiator cap on it. I don't
remember what was on it vs what is on it
now. Maybe 4 to 7. Made all the difference.
Also, the mechanical advance on those
distributors was terrible and with age they
may not work at all. Bad timing can make one
run hot. Lastly, try to run it a little on
the rich side. Those tractors (45 horse)
came from the factory with a marginal
cooling system.

I agree with young fella Old, that it is timing. do you have a little black spring clip under your rotor in the distributor to hold it from rotating on the shaft?