The Most Satisfying Engine Decking Video Ever!

How do engine builders restore a cylinder head that has warped from severe overheating?! 📐⚙️
Inside an internal combustion engine, the cylinder head is clamped against the engine block under massive torque, sandwiching the head gasket to contain thousands of pounds of combustion pressure. However, when an engine severely overheats, the aluminum head undergoes uneven thermal expansion, twisting and warping out of true by just a few thousandths of an inch. Even a gap thinner than a human hair will allow high-pressure cylinder gases to escape and blow the gasket!
To fix this, automotive machine shops mount the head into a precision milling machine equipped with a rotary fly cutter. As the high-speed carbide cutting tool sweeps across the deck, it shaves off a microscopic layer of warped metal, eliminating pits and corrosion. This process—known as "decking" or resurfacing—restores a completely flat, perfectly smooth mating surface so the new gasket can hold full cylinder compression for hundreds of thousands of miles!