Sportsman Racing Products 139831 BBC High-Compression Forged Domed Piston Set, 4.280-Inch Bore, +43cc

Upgrade a Big Block Chevy engine with the Sportsman Racing Products 139831 high-compression forged domed piston set. Designed for performance applications, this set includes eight pistons engineered to support increased compression and durable operation under demanding engine conditions. The domed crown design adds 43.00 cc and is intended for builders seeking improved combustion efficiency and power potential.
The pistons are designed for a 4.280-inch bore and feature a 1.270-inch compression height for compatibility with properly matched BBC engine combinations. Each piston uses 1/16-inch, 1/16-inch, and 3/16-inch ring grooves, allowing the use of commonly specified performance piston rings. Verify bore size, compression height, deck clearance, combustion chamber volume, and ring selection before assembly to ensure the desired compression ratio and piston-to-valve clearance.
Manufactured as a set of eight, the Sportsman Racing Products 139831 pistons are suited for high-performance street, racing, and engine rebuild projects requiring forged construction and a domed piston profile. Proper installation should include careful measurement of cylinder clearance, ring end gap, piston-to-wall clearance, and final compression ratio according to the engine builder’s specifications. This piston set is intended for Big Block Chevy applications and should be matched with the correct connecting rods, crankshaft, rings, and cylinder heads.

Features:

• Brand: Sportsman Racing Products

• Part Number: 139831

• Application: Big Block Chevy engines

• Construction: Forged aluminum piston design

• Piston Style: High-compression domed crown

• Bore Size: 4.280 inches

• Compression Height: 1.270 inches

• Dome Volume: Plus 43.00 cc

• Ring Grooves: 1/16-inch, 1/16-inch, and 3/16-inch

• Quantity: Set of 8 pistons