Wilwood Forged Dynalite Internal Brake Caliper, Black / 0.75–0.83-Inch Rotor Width

The black Wilwood Forged Dynalite Internal is a compact four-piston hydraulic caliper with internal fluid passages. This version combines 1.62-inch stainless piston bores with a nominal 0.81-inch rotor width and 5.25-inch lug mounting centers; match those dimensions to the brake assembly. Bill Wood founded Wilwood Engineering in 1977. Based in Camarillo, California, Wilwood designs and manufactures disc brake systems and parts for motorsport, street-performance and specialized applications, from calipers and rotors to master cylinders, valves, fittings and brake lines.

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.

Technical Details

• Manufacturer part number: 120-13842-BK
• Component: Wilwood Forged Dynalite Internal; one caliper
• Body and finish: Forged aluminum; Black Powder Coat
• Dust boots: No
• Piston arrangement: 4 pistons; 1.62-inch bores; stainless steel
• Hydraulic piston area: 4.12 square inches, as specified by Wilwood
• Mounting: universal side configuration; Lug; 5.25-inch centers; 0.39-inch mounting holes
• Mount height: 2.03 inches
• Fluid inlet: 1/8-27 NPT
• 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

Fitment & Compatibility

Confirm rotor diameter as well as thickness, and allow for pad and caliper clearance inside the wheel. The mount pattern is a dimensional requirement rather than a vehicle fitment guarantee.

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

PMB Performance has over 20 years of brake and parts experience. Send us the caliper specifications, rotor measurements and bracket details if you need help selecting the correct component.