Baldwin B161-S Engine Oil Filter

Baldwin B161-S Engine Oil Filter

The Baldwin B161-S is an engine oil filter built for select Acura, Ford, Honda, Mazda, Mitsubishi, Hyundai, and Kubota applications. It features an anti-drainback valve and a 20 PSID by-pass valve to support oil flow control during startup and under restricted-flow conditions.

Key Features

• Part number: B161-S
• Engine oil filter for automotive and engine applications
• Anti-drainback valve helps retain oil in the filter after shutdown
• 20 PSID by-pass valve
• Integral gasket included
• Thread size: M20 x 1.5
• Outside diameter: 3 1/32 in. (77 mm)
• Height: 4 1/16 in. (103.2 mm)
• Replaces Ford D87Z-6731-A and Mazda 8173-23-802

Detailed Description

Baldwin B161-S is an OE-style engine oil filter specified for a wide range of import and domestic applications, including Honda Civic, Acura Integra, Mazda 626, Mazda B2200, Ford Courier, and Mazda RX-7. The filter’s anti-drainback valve helps keep oil in the filter when the engine is off, while the 20 PSID by-pass valve provides a controlled alternate flow path if the filter media becomes restricted. The B161-S uses an M20 x 1.5 thread and includes an integral gasket for proper sealing.

This part cross-references Ford D87Z-6731-A and Mazda 8173-23-802 for the same application. The Baldwin B161-S is also listed for select Hyundai ix35 and Kubota engine applications, making it a practical replacement choice when matching the correct thread, diameter, and height specifications.

What It Is Used For

• Replacing a worn or clogged engine oil filter
• Restoring proper oil filtration on Honda Civic and Acura Integra applications
• Maintaining oil pressure control during cold starts
• Addressing oil bypass concerns caused by restricted filter flow
• Matching OE-style filter dimensions for Mazda and Ford applications

Installation Notes and Tips

Verify thread size, gasket sealing surface, outside diameter, and height before installation. Confirm vehicle-specific fitment for the exact year and engine configuration, especially on Honda Civic, Mazda 626, Mazda B2200, and Ford Courier applications. Pre-fill only if the engine manufacturer allows it, and always lubricate the gasket before tightening to specification.

Quality Assurance

Baldwin manufactures filtration products for engine protection and service applications. This filter is built with an integrated gasket and internal valve features to support consistent oil filtration performance across the listed fitments.