Slant 6 Oil Pressure Relief Spring Set

The MOPAR PERFORMANCE Slant 6 Oil Pressure Relief Spring Set (P4286571) is a precision engine component designed to maintain optimal oil pressure in Mopar inline-6, B-series, RB-series, and 426 Hemi engines. Set to regulate at 70 psi, this relief spring protects critical engine components by preventing excessive oil system pressure that can cause seal failure, gasket leaks, and accelerated bearing wear during high-rpm operation or cold starts.

Oil pressure relief springs work within the engine's oil pump assembly to maintain a dynamic equilibrium between flow rate and system pressure. The 70 psi setting is engineered to balance adequate lubrication across all bearing surfaces while preventing hydraulic stress on seals and gaskets. Constructed from steel, this spring meets OEM specifications for fitment and durability. Proper relief spring function is especially critical in vintage Mopar engines where original components may have lost tension, or in engines operating at elevated ambient temperatures or under sustained high-load conditions where unregulated pressure becomes a reliability concern.

This relief spring set is essential for restoration, engine rebuild, and maintenance of classic Mopar muscle cars and trucks. Technicians performing oil pump service, engine gasket work, or pressure system diagnostics will find this spring set necessary to restore factory oil regulation. A worn or weakened relief spring often goes undiagnosed during routine maintenance but manifests as chronic oil leaks, bearing noise, or pressure gauge fluctuation—symptoms that point directly to relief valve function. Availability of OEM-spec replacement springs ensures the oil system performs as originally engineered.