Manley 597420C-8 in our Pistons Deptartment

Bore: 3.937" / 100mm
Rod Length: 6.240"
Stroke: 3.579" / 90.9mm
Comp Distance: 1.220"
Comp Ratio: 9.72:1 @ 85cc,11:1 @ 74.5cc
Pin Diameter: .927"
Weight: 435g (w/ Pin 530g)
Piston Type: 9.3cc Dome

Manley pistons are machined of high strength 2618 material. Each design is lightweight yet robust enough to deliver long service life. Perfect ring groove to skirt squareness is achieved through our unique one fixturing manufacturing method that assures maximum horsepower. We utilize a proven offset wrist pin design, a 1.5, 1.5, 3mm Total Seal ring package and moly coated skirts for ultimate performance. Roundwire locks, tool steel wrist pins and pressure balance grooves are included with every set at no additional charge.

Forging

• 2618 alloy for maximum high temperature strength and fatigue resistance.
• 4032 High Silicon alloy for budget conscience street applications. (49 series Ford Modular only)

Attributes

• Contour forgings provide the optimum balance between strength and weight with no grain-interrupting internal milling.
• Proprietary multi-step top ring groove machining process assures optimum control of the grooves size, geometry, flatness, and finish.
• All final turning is performed in one fixturing resulting in complete squareness of rings to the cylinder wall.
• Federal Form-Scan gauging validates ideal skirt indexing to pinhole and skirt-to-skirt polarity.
• Value added features such as a pressure balance groove included in all series.
• Precise pinhole machining results in an exact compression distance as well as precise lock ring groove spacing, size, and concentricity.
• Moly coated skirts come standard on all Ford Modular pistons and are optional on the Chevy LS and Chrysler HEMI pistons.
• Offset wrist pin design ensures more quiet start-ups and better performance.

Note: Compression ratios are calculated at 0.00 deck clearance, a 9.240 deck height, and a .042 thick compressed head gasket.