SneedSpeed Cylinder Head Stud Kit for MINI Cooper S & JCW (R55–R59, N14/N18 Engines)
Overview
The SneedSpeed Cylinder Head Stud Kit is a performance-engineered fastener upgrade designed specifically for turbocharged MINI Cooper S and JCW R55–R59 models equipped with N14 or N18 engines. It replaces the stock torque-to-yield head bolts with high-strength chromoly studs that deliver superior clamping force, improved sealing, and long-term reliability—especially under boost and high RPM conditions.
What This Does
Factory head bolts on BMW/MINI N14/N18 engines are single-use, torque-to-yield fasteners that stretch and lose tension over repeated heat cycles. This loss of clamp force can lead to head lift, gasket failure, coolant leaks, and inconsistent compression—especially on tuned or boosted engines. Upgrading to a stud kit helps eliminate these failure points by providing consistent, high-strength clamping and reusable hardware.
Key Features
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High-Strength 8740 Chromoly Studs: Heat-treated and centerless-ground studs rated around 220,000 psi tensile strength provide significantly higher load capacity than stock fasteners, making them ideal for boosted or high-RPM performance applications.
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Reusable Design: Unlike OEM torque-to-yield head bolts, these studs can be reused during future rebuilds or maintenance, reducing long-term service cost and effort.
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Consistent Clamping Force: The stud-and-nut arrangement minimizes thread friction and provides even, repeatable torque and preload across the cylinder head—improving sealing stability and reducing the likelihood of head gasket leaks.
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Complete Kit: Includes studs, hardened washers, and 12-point nuts engineered for precise torque application; full installation instructions are provided.
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Direct Fit, No Modifications: Designed to fit R55–R59 MINI Cooper S and JCW models with N14 or N18 engines without any block or head modifications.
Benefits
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Boost-Ready Reliability: Stronger clamp loads help prevent head gasket failure in forced-induction and tuned engines.
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Improved Head-to-Block Sealing: Maintains compression and coolant sealing under aggressive thermodynamic loads.
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Better Serviceability: Studs stay in the block while nuts are removed, reducing wear on block threads and speeding up teardown/reassembly.
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Ideal for Performance Builds: Recommended upgrade for track cars, high-power street builds, and any engine where long-term durability and consistent torque control matter.
Application
This kit is appropriate for:
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Turbocharged R55–R59 MINI Cooper S and JCW models with N14/N18 engines
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Builds with elevated boost, tuned ECUs, or aggressive driving profiles
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Engine rebuilds where long-term head sealing integrity is required
