4.00 Inch 3 Bolt Flange

The Quick Time Performance 4.00 Inch 3 Bolt Flange (part number 10400F) is a precision header flange engineered for high-performance engine builds requiring robust exhaust manifold-to-pipe coupling. This 4-inch round port steel flange features a 0.375-inch thickness and zinc-plated finish, delivering the structural integrity and corrosion resistance required for sustained high-RPM operation and variable thermal cycling inherent to performance and racing applications.

The three-bolt mounting pattern provides reliable fastening geometry widely used in custom exhaust systems, headers, and turbo manifold applications. The 4.00-inch bore diameter accommodates standard tuned-length headers and collector sizing for mid-range displacement engines. Zinc plating protects the steel substrate against oxidation and surface corrosion, extending service life in both street and track environments. At 0.89 pounds, the flange maintains minimal weight while preserving the metallurgical demands of high-temperature exhaust flow and pressure cycling. Precision machining ensures flat sealing surfaces and concentricity critical to exhaust system integrity and prevention of leakage under load.

This flange suits builders, fabricators, and performance shops constructing or repairing custom headers, turbo manifolds, and standalone exhaust systems. It is suitable for street performance vehicles, track-focused builds, and engine builders requiring OEM-quality fastening solutions. The standardized three-bolt pattern ensures compatibility across multiple header designs and aftermarket collector configurations commonly found in American V8 and inline engine builds.

Quick Time Performance specializes in exhaust components and engine accessories for the performance aftermarket. The 4-inch flange represents a foundational coupling component—modest in appearance but critical to system reliability. Buyers sourcing header flanges should verify three-bolt port spacing, bore diameter, and flange thickness against their specific manifold or tubing specifications before purchase to ensure proper assembly and seal integrity.

Whether you're assembling a custom exhaust system for a project engine or replacing a damaged flange, this Quick Time Performance part delivers verified dimensions and durable steel construction backed by zinc protection. Shop TacticalSurplusUSA for hard-to-find engine and exhaust components at competitive pricing.