Cylinder Head Bolts and Studs

Engine Works Torque-to-Yield Head Bolts

Engine Works torque-to-yield (TTY) headbolts are specialized, single-use fasteners designed to stretch permanently beyond their elastic limit during installation, ensuring precise, consistent clamping force for modern engines. Unlike conventional bolts, they're tightened to a specific angle, not just torque, preventing head gasket failure. Kits are available for a variety of applications, including many Chevrolet engines from 1999 and up. Key details: * TTY bolts are designed to stretch plastically (permanently) into their "yield zone" to achieve optimal clamping force, meaning they cannot be reused * They're installed by tightening to a low torque value, followed by one or more 90-degree angle turns * Commonly used in modern aluminum engines with cast iron blocks (i.e. LS, Hemi, Coyote) to manage different thermal expansion rates * Advantages: Provide superior, consistent clamping load across the entire engine block, reducing the risk of head gasket failure in high performance or high-heat applications * Using specialized tools like a torque angle gauge is required for proper installation of these fasteners

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