409 c.i, 4.140" Bore, 3.800" Stroke, 5.850" rod length, -4.5cc dome volume

J281800

81800

These pistons incorporate the results of extensive collaboration with top engine builders. Precision CNC-machined ring grooves now accept 1.2, 1.5, 3.0mm rings for reduced friction, while Lateral Gas Ports have been added for improved ring seal. This new configuration outperforms the competition hands down! Pin upgrade recommended above 700hp. Includes: Double spiro locks #927-042-CS Pin #927-2750-15-51S (130g) Features: Double Pin Oilers Lateral Gas Ports Accumulator Grooves Piston Specifiaction: Make: CHEVROLET Engine:SMALL BLOCK CHEVROLET Bore Diameter: 4.140 Compression Height: 1.250 Compression Ratio with 40cc chamber volume: 16.5 Compression Ratio with 45cc chamber volume: 15.2 Compression Ratio with 50cc chamber volume: 14.1 Piston Volume: -4.7 Cylinder Head: CHEVROLET 13 DEG PistonPin Outside Diameter: 0.927 Piston Pin Length: 2.750 Piston Pin Material: 5115 Ringset Included: No Top Compression Ring Thickness: 0.0475 Second Compression Ring Thickness: 0.06 Oil Ring Thickness: 0.119 Piston Material: 2618 Forging Type: Round Piston Avg Weight: 476 Pin Wall Thickness: 0.150 Piston Type: Dome