Gen III HEMI Engine Block – CGI HEMI Block

The ACE INC Gen III HEMI CGI block is cast and machined in-house at our Michigan foundry and CNC cell. Compacted graphite iron gives it the stiffness to hold ring seal and main alignment under serious cylinder pressure, with full water jackets so the same block works on the street and at the strip. Every casting is serialized and ships with its own inspection documentation.

Features

Material and Structure

• Compacted Graphite Iron, 450 MPa minimum tensile strength (GJV-450)
• Big bore capability to 4.310" (109.5 mm), with 4 mm minimum cylinder wall thickness at max bore
• Three deck heights: 9.285", 10.5", and 10.75"
• 19 mm (0.75") minimum deck thickness on 9.285" and 10.5" decks; the 10.75" deck carries an additional 0.25" for a full 1" (25.4 mm) minimum deck
• 6-bolt 4140 billet steel main caps on all 5 mains

Valvetrain and Rotating Assembly

• Race cam and splayed lifter options for high RPM and ACE INC high-flow heads: up to 82 mm cam journals and 1.2" roller lifters in guided, bushed bores
• Stroker clearance for 5.100" stroke with 2.200" rod journals

Head Fastening

• M14 head stud threads in the deck for stronger thread engagement in the CGI. Standard studs neck to an M12 fine nut end; an optional M14 both-ends stud delivers up to 36% more clamp load than an M12 fastener
• 9.5" head studs for roughly 50% more stretch compliance. Clamp load stays stable through a knock event, and cylinder wall stress concentration moves to the bottom of the bore where sealing demand is lowest

Oiling and Cooling

• Revised oiling: true priority main oil gallery, dedicated lifter secondary circuit, and a straight filter-to-MOG feed with no 90° turns causing pressure drop or cavitation
• Dry sump oil feed provision at the front face of block or at the oil filter feed
• Fully water jacketed. Race block strength, street driveable
• Cast-in -8 ORB oil drain-back ports at the pan rail by cylinders 1 and 2

Fitment and Quality

• 100% stock mount compatibility, including TRX engine mounts and SUV front differential mounts
• Serialized castings
• Every block ships with its CMM report and full QC documentation covering both casting and machining