Earl's Performance Billet Aluminum Sandwich-Style Oil Thermostat

Earl's Performance Billet Aluminum Sandwich-Style Oil Thermostats are precision-engineered to regulate engine oil temperature when running an external oil cooler. Designed for quick, controlled oil warm-up, these thermostats protect your engine from the wear caused by cold, thick oil during start-up while also preventing overcooling under demanding operating conditions.

The sandwich-style design installs compactly between the oil filter mounting boss and the oil filter itself, keeping the installation clean and straightforward without requiring extensive plumbing changes. Until the oil reaches proper operating temperature, the thermostat bypasses the oil cooler entirely — then gradually transitions to full cooler flow as temperatures rise, maintaining optimal oil viscosity and lubrication at all times.

Key Features:

• Precision-machined billet aluminum construction for strength, durability, and corrosion resistance
• Thermostatically controlled bypass keeps oil away from the cooler during warm-up, then progressively opens for full cooler flow at operating temperature
• Large internal passages and -10 AN O-ring fitting ports for full, unobstructed oil flow
• Compact sandwich-style design mounts between the oil filter boss and oil filter — no major plumbing required
• Suitable for automotive, marine, air-cooled, and towing applications
• Especially beneficial in cold climates where rapid oil warm-up is critical
• Available in multiple thread sizes and configurations to fit a wide range of applications

Earl's Performance is a trusted name in high-performance plumbing, AN fittings, and oil system components. Their billet oil thermostats are an essential addition to any build running an engine oil cooler, ensuring your engine reaches ideal operating temperature quickly and stays there.