CP Pistons & Rod Set – 4.020″ Bore, 3.750″ Stroke for Small-Block Chevrolet

Description

CP Pistons Bullet Race Series Small Block Chevy 4.020 bore, 3.750 stroke, 6.000 rod set of 8 delivers a precision piston and rod package engineered to provide dependable, race-ready componentry and consistent mechanical integrity under high‑duty operation.

This kit is built around the core function of replacing or upgrading the rotating assembly for Small Block Chevy applications: eight matched pistons sized to a 4.020″ bore paired with connecting rods for a 6.000″ rod length, configured for a 3.750″ stroke crank. That controlled combination of bore, stroke and rod length is intended to simplify assembly and ensure dimensional compatibility across all eight cylinders.

• Matched set of eight pistons — ensures uniform compression and balanced reciprocating mass across the engine, reducing the need for additional matching and helping maintain consistent combustion characteristics.
• 4.020″ bore sizing — specifies the piston diameter for accurate cylinder clearance and ring seating, which is critical for sealing and long‑term reliability.
• 3.750″ stroke compatibility — identifies the crankshaft stroke the assembly is intended to work with, supporting correct piston-to-deck and wrist‑pin geometry when combined with the specified rod length.
• 6.000″ rod length — provides the rod centerline-to-centerline dimension used to calculate rod ratio and piston speed, aiding precise piston dwell and mechanical timing when designing or verifying engine geometry.
• Bullet Race Series designation — indicates a product line focus on track and competition environments, offering components packaged for performance engine builds and rebuilds.
• CP Pistons brand — a recognized supplier name used to identify manufacturing standards and quality control associated with the CP Pistons product family.

Functionally, this package eliminates ambiguity during a Small Block Chevy build by specifying the piston bore, crank stroke compatibility and rod length in a single matched set of eight, which streamlines balancing and assembly workflows for engine builders and shops.

Technical notes to consider during installation and engine design:

• Match piston bore to block cylinder finish — confirm block re-bore or hone dimensions to the 4.020″ specification before assembly.
• Verify crank and deck clearances — use the 3.750″ stroke and 6.000″ rod length to calculate piston-to-deck and wrist‑pin position for correct compression height and ring placement.
• Balance rotating assembly — treat the set as matched reciprocating mass but perform final dynamic balancing to factory or race tolerances.

This product is supplied by CP Pistons and is intended for builders specifying a Bullet Race Series piston and rod solution for Small Block Chevy platforms requiring the 4.020″ bore, 3.750″ stroke compatibility and 6.000″ rod length in a set of eight components.

Explore more from our collection.