Quote:
Originally Posted by LATECH
Sorry dude .you be wrong LOL
Welch plugs are named for the hole that is left in the casting or the "welch" of casting where the sand core is supported to cast said engine block. Then they bore the hole to a specific size and fit it with a plug.It fills the "welch" in the casting.
They also are used to block the end of a intersecting passage, say like in a carburetor where fuel passes from one channel to the next
Not much fuel freezing ,even where I live.
They do tend to pop out sometimes when an engine block freezes, but wont protect it ,like some people commonly Believe. Probably why some folks call them freeze plugs. They do not protect the block from damage of frozen coolant, water....
Freeze plug is a common misnomer.
I am sure I will catch some slack for this info.
Fire away.
Straight from McMaster Carr...
https://www.mcmaster.com/welch-plugs/ |
No way, I am never wrong - ever. LOL
"
Core plugs are usually thin metal cups press fitted into the casting holes, but may be made of rubber or other materials. In some high-performance engines the core plugs are large diameter cast metal threaded pipe plugs."
"The
Welch plug is a type of core plug that is made from a thin disc of metal. The Welch plug is dome-shaped and inserted into the casting hole with the convex side facing outwards. When installed by striking the Welch plug with a hammer, the dome collapses slightly, expanding it laterally to seal the hole.
This differs from other dish-shaped core plug designs, which form a seal when their tapered sides are pressed into the casting hole. The Welch plug was originally designed in the 1900s at the Welch Motor Car Company in the United States." Example: Place the new Welch plug, concave side down, in the hole. Smack the dome of the Welch plug with a hammer. This will spread and seal the Welch plug.
"Holes in the side of the engine block which are plugged with a
dish shaped metal plug called a "
freeze plug" or "expansion plug". As with many things on a car, there is an "official reason" and a "REAL" reason for freeze plugs.
The official reason (and the source of the name) is this: If you run just water with no antifreeze in your car's cooling system the water can freeze. When water freezes, it expands. If water freezes inside your engine block, it can expand and crack the block, destroying the motor. Freeze plugs (or expansion plugs) will "pop out" and supposedly prevent this. In reality this doesn't work all the time: I've seen MANY blocks destroyed by cracking without the freeze plugs popping out, or if they do pop out the block cracks anyway."