Wilwood Polished Dynalite Internal Caliper with 4 Pistons, Lug Mounting, 1.38-Inch Bore

The Wilwood Forged Dynalite Internal is specified for 0.81-inch rotor width, 5.25-inch lug mounting and 1.38-inch piston bores. This polished 4-piston component is selected by brake-system geometry rather than vehicle year alone. Founded in 1977 by Bill Wood, Camarillo, California-based Wilwood Engineering manufactures disc brake components for motorsport, street-performance and specialized uses. Its range covers calipers, rotors, master cylinders, valves, fittings and brake lines.

Technical Details

• Manufacturer part number: 120-13839-P
• Component: Wilwood Forged Dynalite Internal; one caliper
• Pad shape: Wilwood type 7112; compound selected separately
• Rotor width: 0.81-inch nominal; 0.75–0.83-inch permitted range
• Rotor diameter range: 10.00–13.06 inches
• Mounting: universal side configuration; Lug; 5.25-inch centers; 0.39-inch mounting holes
• Mount height: 2.03 inches
• Piston arrangement: 4 pistons; 1.38-inch bores; stainless steel
• Hydraulic piston area: 3.00 square inches, as specified by Wilwood
• Fluid inlet: 1/8-27 NPT
• Body and finish: Forged aluminum; Polish
• Dust boots: No

Fitment & Compatibility

Select pads by the specified friction shape and intended operating temperature. Check the wheel template with the actual rotor, hat and bracket before finalizing the installation.

This listing covers one caliper. Match the brake pads, rotor, hose and mounting arrangement to the complete brake system.

This four-piston Dynalite uses internal fluid transfer in a spacerless body. Its 5.25-inch mounting pattern is only one compatibility dimension: rotor position, body clearance and hydraulic area also need to agree.

PMB Performance’s team has over 20 years of experience with brake components and fitment. We can help review this caliper against the dimensions and hydraulic requirements of your brake system.