"WT" Water test. What does this really mean?

[incinr8]

So in doing some investigation, WT on the block means "Water test". Does anyone know what exactly that means? Why is it on some engine and not others? Can anyone describe the process? Thanks in advance

 

[Lefty71]

If you mean specifically how did the factory do it?, can't be positive. But in a conventional sense, it means, they pressurized the block from the water pump passages after the heads and exhaust mainfolds were installed on a big block. Intake on to on a small block. Maybe five pounds and then watched for a drop in pressure. Now why??? I know why you or I might do it, before you go any further on a motor build. I would suspect the factory reasoning was the same, maybe a defect they saw in the iron, that would'nt necessarily mean "scrap pile" if it passes the water test. No defects to the naked eye, no need for the WT. Also, maybe they did every 25, or 50, or 100, to keep the tooling honest, if you know what I mean.

 

[Dipstick]

I would think they merely blocked off the head surface and pressurized the block. Again, to test the block casting for porosity.

 

[Jerry Hall]

I would think they merely blocked off the head surface and pressurized the block. Again, to test the block casting for porosity.

I couldn't be sure where in the process they would do the WT, but I fully agree with them possibly seeing a possible defect in the casting and checking futher. Also could have been every so many blocks. As dependable as these drivetrains were in the day, I think they were high on quality control in the drivetrain department. Sure there were problems, but on the HP cars, I would guess customer abuse.

 

[mopar 3 B]

Don't know either, but do know why I do it. Especially when installing any thing newly purchased. Nice to know where the leaks are if any before it goes in.