VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Water Pump Question

I dont like the "bubbling" bit, it generally indicates a combustion leak. Here in Aus we have a test fluid that changes color when combustion gases are detected in the vapours coming out of the radiator.
The compressions are within in the 10% but in comparison to modern engines are rather low but with those lower compression ratios could well be OK.
Tony

Before taking off the head go to your local parts store and get a combustion gas test kit. It detects CO2 from combustion in the radiator. Cracks in the exhaust passages as well as the combustion areas can cause overheating.

Well I got it checked out by a professional and there are no combustion gasses in the cooling system... back to square one.

Anyone have any insight?

Thanks,
-Davis

Davis,

Here is my take on this issue:

If the flues and fins are open in the radiator

and the water pump is pumping

and the block is clean

and there is no gases going into the water jackets

and the water is half-way the top tank when it is cold

and there is no stuck thermostat

and there is no collapsing or collapsed (interior) hose(s)

Then it is not overheating. You may be hallucinating, on something more potent than some spirits made without taxes being paid, or that filter thing you told us about is a-messing up or the sending unit bad.

Given the above positive conditions, there just ain't no way, that I can figure that it can overheat. Get hot yes, but overheat, no.

Charlie

Davis,

'Suggest you do as I had to do. The Temp gauge on the '41 doesn't "zero" when dead cold. It is up the scale a bit. Occasionally, it got over "in the red". The rad never burped or boiled.

With a cold engine, remove the rad cap and insert a dependable stem-type thermometer. Make sure it is submerged well into the coolant. Start the engine and set the throttle or the idle screw to a healthy (safe) idle speed. As the temp begins to rise, make frequent notes of the readings of the thermometer and the temp gauge (use 2 columns) until the dash gauge reaches its high point. The thermometer will keep you informed. Of course, don't allow it to overheat to a dangerous point.

When you are finished, you will know exactly how accurate your temp gauge is and whether you have an overheating situation or if the gauge is lying.

Keep your notes in the glove box for future reference (lest I forgets!).

I did this on my '41 (and earlier on a '47 Ford Convertible). Both gauges were lying on the hot side but the engine/s were not overheating in the least. Sometimes these ol' gauges get tired and undependable.

Well, I had it checked for gasses and it came back negative. However I added some rust inhibitor to the cooling system and then started getting water in the oil. So I took the head off and am having it checked for any cracks or warpage. The old head gasket doesn't appear to have any breaks or imperfections. It doesn't look like any sealant was used when it was put on. Should I use some when I put the new head gasket on? If so what exactly should I use?

Thanks,
Davis

"modern" head gaskets do not require a sealant.....but there should be instructions with the new head gasket.