New Ford/Mazda 4.0 OHV Cylinder Head for Ranger, B4000, Explorer (1990-1995)

New Ford Mazda 4.0L OHV Cast Iron Cylinder Head (1990–1995)

Premium OEM-Quality Replacement Cylinder Head

Restore your engine’s mechanical integrity with this all-new 4.0L OHV ‘Cologne’ cylinder head, specifically engineered for 1990–1995 Ford Explorer, Ranger, and Mazda B4000 applications. This fresh, high-density cast iron unit features reinforced internal water jackets and an upgraded deck thickness to eliminate the thermal stress cracking common between the intake and exhaust seats in original thin-wall factory castings. Although the gasket surface is pre-milled, every unit undergoes an in-house precision verification to ensure the Surface Roughness (Ra) meets the strict requirements for modern composite head gaskets, preventing localized hot spots and coolant seepage. We perform final guide sizing and multi-angle valve seat cutting on our Rottler equipment to ensure perfect valvetrain geometry and a 100% airtight seal. Pressure tested to 60 PSI and built to exceed OEM durability standards, this head provides a permanent, professional-grade solution for the 4.0L OHV platform.

🛠️ In-House Machining Process

• Debris-Free Preparation: Every new casting is chemically cleaned and blown out to remove all residual machining oils, metal shavings, and manufacturing debris. This ensures your oiling system remains uncontaminated from the first start-up.

• In-House Precision Machining: Unlike “shelf-stock” heads, we perform all final machine work in-house. This includes final guide sizing and precision valve seat cutting to ensure perfect geometry and clearances before the head reaches the assembly bench.

• Pressure & Integrity Testing: To go beyond the factory standard, we pressure-test every head to 60 PSI. This verifies that the casting is free of porosity leaks or internal defects that could compromise the cooling or oiling systems.

• Dimensional Inspection: Our technicians perform a multi-point inspection of the gasket-sealing surface and bore alignment. This ensures the head is perfectly flat and meets tight OEM tolerances for a flawless fit.

• Professional Assembly & Setup: Valvetrain components are installed and verified in a clean-room environment. We check spring heights and seal seating to ensure the assembly is balanced and ready for high-performance use.

• Vacuum-Seal Verification: Every intake and exhaust port is Vacuum Tested. This guarantees a 100% airtight seal between the valves and seats, ensuring maximum compression and peak performance right out of the box.

📊 Technical Specifications

• Engine Size: 4.0L OHV
• Condition: Brand New
• Assembly: Fully Assembled with Valves, Springs, and Seals
• Torque Spec: Rocker Arm Torque: 30 ft-lbs
• Core Return Required
• Each Cylinder Head Includes: Valves and Springs Installed

🚛 Fitment Data

Common Applications:

• Ford Aerostar: 1990–1994 Ford Aerostar 6-245 (4.0L)
• Ford Explorer: 1991–1994 Ford Explorer (4.0L)
• Mazda B4000: 1994 Mazda B4000 (4.0L)
• Mazda Navajo: 1991–1994 Mazda Navajo (4.0L)
• Ford Ranger: 1990–1994 Ford Ranger 6-245 (4.0L OHV)