Wiseco K478BS BBC Quick 16 Series 42cc Semi-Hollow Dome Piston Kit 4.500 in. Bore 1.120 in. CH

The Wiseco K478BS is a forged Big Block Chevrolet (BBC) Quick 16 Series piston kit featuring a +42cc semi-hollow dome and a 1.120 in. compression height designed for 24° conventional head applications. Built from high-strength 2618 aluminum alloy at Wiseco's Mentor, Ohio facility, this piston kit delivers the durability and precision required for serious high-performance street and drag race builds targeting high compression ratios near the 16:1 range.

Key Specifications:

• Bore: 4.500 in.
• Compression Height: 1.120 in.
• Dome Volume: +42cc Semi-Hollow
• Dome Style: Gas Ported Semi-Hollow Dome
• Compatible Strokes: 4.250 in. / 4.375 in.
• Compatible Rod Lengths: 6.535 in. / 6.480 in.
• 0 Deck At: 9.780 in. / 9.787 in.
• Standard Deck Height: 9.800 in.
• Piston Weight: 600 grams (avg.)
• Skirt Type: Strutted
• Head Type: 24° Conventional
• Pin Included: S726 — 0.990 in. x 2.930 in. Toolsteel Wall Pin
• Pin Retention: Double Spirolox®
• Ring Grooves: .043 / 1/16 / 3/16 (rings sold separately — JG86H8-4500-5)
• Material: 2618 High-Strength Aluminum Alloy

Compression Ratios (approximate, at 0 deck with 0.040 in. gasket):

• At 107cc combustion chamber: 15.8:1 / 16.3:1
• At 114cc combustion chamber: 14.6:1 / 15.0:1
• At 119cc combustion chamber: 13.9:1 / 14.2:1
• At 123cc combustion chamber: 13.3:1 / 13.7:1

Key Features:

• ArmorGlide® Skirt Coating — reduces friction, resists seizure, and quiets piston operation
• Vertical Gas Ports — improves ring seal and combustion efficiency
• Anti-Detonation & Pressure Seal Grooves — enhances ring stability under high cylinder pressures
• 2618 Alloy Forging — engineered for strength in power-adder and naturally aspirated high-compression applications
• Strutted Skirt Design — optimized strength-to-weight ratio

The Quick 16 Series is purpose-built to achieve compression ratios near 16:1 using today's conventional head designs, making the K478BS an ideal choice for high-output naturally aspirated or nitrous-assisted BBC builds. Rings are sold separately; wrist pin S726 is included.