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Gregory Avery
12-23-2006, 08:28 PM
Have a 1953 Champion C-coupe with 169 flathead six. Went to rebuild carburator and found antifreeze in intake manifold. Dried it out with towels and for kicks put carb back on and started motor. Pulled the carb back off and low and behold more antifreeze.If head gasket was blown I would think steam would come out the exhaust pipe. It does not- even while reving the motor.Have not seen dramatic drop in radiator level and oil is crystal clear and so is breather cap area.Motor sounds and runs perfect.Anyone got any suggestions were to procede from here?? Gut instincts tell me to pull the head but hate to do that for nothing if it could be something else.Appreciate any and all feedback Gregg

gordr
12-23-2006, 09:29 PM
quote:Originally posted by Gregory Avery

Have a 1953 Champion C-coupe with 169 flathead six. Went to rebuild carburator and found antifreeze in intake manifold. Dried it out with towels and for kicks put carb back on and started motor. Pulled the carb back off and low and behold more antifreeze.If head gasket was blown I would think steam would come out the exhaust pipe. It does not- even while reving the motor.Have not seen dramatic drop in radiator level and oil is crystal clear and so is breather cap area.Motor sounds and runs perfect.Anyone got any suggestions were to procede from here?? Gut instincts tell me to pull the head but hate to do that for nothing if it could be something else.Appreciate any and all feedback Gregg


Hmmm. The head gasket doesn't directly seal any of the intake ports, as far as I know. And there is no water passage in the intake manifold itself, unless you have one of the aftermarket dual-carb manifolds with a water passage cast in it.

I'd be thinking maybe a cracked block in the vicinity of the valve seats, with the crack extending into the intake port.

What to do?

1. Do a cooling system pressure test, using one of those gage/pump tools. Try it with a cold engine, and again with a warm engine.

2. Pull all the spark plugs, and see if any are unusually clean and white on the insulator tip. A water leak will sometimes "steam-clean" the plug on the cylinder involved.

3. Do a compression test while all the plugs are out, preferably after the engine has been warmed up. A cracked block might show lower compression.

4. Suggest you remove the manifolds before removing the head. A bit less work, and if you see antifreeze pooled in one of the ports, it narrows down your search. If nothing shows, at least you can do a valve adjustment while the manifold is off.

5. If all else fails, remove the head.

Hope this helps,

Gord Richmond, within Weasel range of the Alberta Badlands

John Kirchhoff
12-23-2006, 11:24 PM
I haven't worked on a flathead stude, but I was looking at the picture in the shop manual. I saw what appears to be an oval shaped hole in water jacket outside of the valves. If the head gasket was leaking between there and the combustion chamber, the vacuum created in the intake cycle could possibaly pull fluid through the bad gasket. If it's just a very small seep, I wonder if a drip or two forms and runs down past the open valve and into the manifold. Antifreeze doesn't vaporize worth a hoot, so the drip could stay in a liquid form and be subject to gravity even though the intake charge is going the other direction. Maybe I'm just speculating though. I could also see the block being cracked as Gord suggested but at least in my experience with cracks between the valves in overhead valve engines, it's the compression that leaks into the cooling system and not the other way around. Do as Gord suggested and you should be able to narrow things down. I suspect the head gasket and fortunately, it's extremely easy to pull on your engine.