Billet Alum Oil Filter By-Pass Adapter

The EARLS Billet Aluminum Oil Filter By-Pass Adapter (Model 1178ERL) is a precision-engineered oil filtration component designed for high-performance and racing engines where auxiliary oil circulation becomes critical. This black anodized aluminum bypass adapter functions as a secondary oil routing solution, allowing unfiltered oil to reach vital engine components during cold starts or high-demand operation, protecting bearings and journals when conventional filter systems cannot keep pace with engine demand.

The adapter features a 3/4-16 center thread configuration with dual 1/2-inch NPT female inlet and outlet ports, enabling flexible integration into existing oil systems. The 2-3/4-inch O-ring provides a reliable seal across temperature cycling and pressure spikes common to modified and racing powerplants. Billet aluminum construction delivers weight savings compared to cast iron counterparts while maintaining structural integrity under sustained load. The black anodized finish resists corrosion and oil degradation in engine bay environments.

This bypass adapter is specified in high-revving applications—drag racing, circle track, marine performance builds, and turbocharged street engines—where supplemental oil flow prevents starvation at the crankshaft and rod journals during transient acceleration. Proper sizing of bypass passages ensures that oil pressure remains within design limits while maintaining flow rates that exceed conventional single-stage filtering. Installers and engine builders select this component when OEM cooling capacity is insufficient for aggressive duty cycles.

EARLS is recognized for precision machine work and tight tolerances in oil system products; this adapter carries that standard. Compatibility depends on existing port locations and manifold design, so verification against your engine's oil gallery layout is essential before ordering. Weighing 0.53 lbs and measuring 4 x 1.6 x 6 inches, the compact footprint suits tight engine compartments without requiring extensive re-routing.