Performance With Heart

Gen III Hemi CGI engine blocks — lighter than cast iron, 3x stronger than aluminum, with 20x less bore distortion. Engineered to deliver 3–5% more torque and power through superior bearing stability and cylinder sealing.

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3X
Stronger Than Aluminum
20X
Less Bore Distortion
3–5%
More Power
14mm
Head Stud Capacity
PRE-ORDER Blocks expected to start shipping Late May 2026. Reserve yours today — orders fulfilled in the sequence received.

CHOOSE YOUR BLOCK

Four configurations. One material advantage. Every block rated to 3,000 HP.

Most Popular
Variant 1 - Stock Replacement

ACE STREET

The drop-in CGI upgrade. Full factory compatibility.

$4,200 In Stock
Bore & Finish 4.085 Rough
Deck Height & Lifter Standard 9.30 / Stock Lifter
Timing & Cam VCT / Stock Cam
HP Rating 3,000 HP
Application Street / Daily / Mild Performance

Ships direct to your door

Variant 2 - Forced Induction

ACE BOOST

Tall deck strength meets factory electronics compatibility.

$5,200 In Stock
Bore & Finish 4.205 Rough
Deck Height & Lifter Tall 10.25 / Stock 74 Degree Lifter
Timing & Cam VCT / Stock Cam
HP Rating 3,000 HP
Application Turbo / Supercharger / High Boost

Ships direct to your door

Variant 3 - Drag Racing

ACE DRAG PAK

Purpose-built for straight-line domination.

$5,700 In Stock
Bore & Finish 4.120 Rough
Deck Height & Lifter Standard 9.30 / Splay Roller Guided
Timing & Cam Non-VCT / 60mm Roller
HP Rating 3,000 HP
Application Drag / Bracket / Grudge Racing

Ships direct to your door

Variant 4 - Naturally Aspirated

ACE MAMMOTH

Maximum cubic inches. Maximum naturally aspirated power.

$6,900 In Stock
Bore & Finish 4.260 Honed (NA Only)
Deck Height & Lifter Tall 10.25 / Splay Roller Guided
Timing & Cam Non-VCT / 60mm Roller
HP Rating 3,000 HP
Application Max CI NA / Pro Street / Show

Ships direct to your door

PRE-ORDER Blocks expected to start shipping Late May 2026. Reserve yours today — orders fulfilled in the sequence received.
Custom Configuration

BYOB - BUILD YOUR OWN BLOCK

None of the four standard variants fit your build? Configure a fully custom ACE CGI engine block with your exact specifications.

BORE SIZE & FINISH

STEP 1

Rough bores ship .003" undersize for your machine shop to finish. Honed bores are plateau-honed to final size, ready for ring fit.

⚠ Rough bores ship .003" undersize for your machine shop to finish-hone.

DECK HEIGHT & LIFTER

STEP 2

TIMING DRIVE & CAM TYPE

STEP 3
YOUR CONFIGURATION

ACE BYOB BLOCK

PART NUMBER ACE-CGI-XXXXX
0 of 3 selections made
Bore & Finish Select...
Deck & Lifter Select...
Timing & Cam Select...
Base Block $4,200
Total $4,200

Complete all 3 selections to continue

3,000 HP RATED - ALL CONFIGURATIONS

WHY COMPACTED GRAPHITE IRON

The material OEMs trust for the most demanding applications on earth.

⚡

SUPERIOR STRENGTH

75% higher tensile strength than conventional gray iron. CGI's unique graphite structure creates a material that absorbs extreme cylinder pressures without cracking or distortion.

75% STRONGER
🔩

MAXIMUM STIFFNESS

45% higher elastic modulus means dramatically less bore distortion under load. Your ring seal stays consistent from idle to wide-open throttle — critical for high-boost applications.

20× LESS DISTORTION
🔥

THERMAL MANAGEMENT

CGI maintains dimensional stability across extreme temperature cycles. Superior vibration damping reduces NVH and extends component life compared to aluminum alternatives.

2× FATIGUE LIFE

FREQUENTLY ASKED QUESTIONS

WHAT IS THE DEPOSIT REFUND POLICY?

Deposits are fully refundable up until production begins. Once manufacturing starts, deposits are non-refundable but may be transferred to a different variant.

WHEN WILL MY BLOCK SHIP?

Production timeline is approximately 16–24 weeks from presale close. You will receive regular updates and tracking information when your block ships.

CAN I USE THIS AS A DIRECT REPLACEMENT?

The ACE Street variant is a direct drop-in replacement for factory Gen III Hemi blocks with full VCT and stock component compatibility. Other variants may require supporting modifications.

IS CGI REALLY RATED TO 3,000 HP?

Yes. CGI's material properties — 75% higher tensile strength, 45% higher stiffness, and 2× fatigue life compared to gray iron — support extreme power levels with proper supporting components.

WHAT ABOUT NHRA/IHRA APPROVAL?

ACE INC is actively pursuing NHRA and IHRA approval for Factory Stock Showdown competition. CGI qualifies as a cast iron derivative material under current rulebooks.

WHERE CAN I BUY AN ACE BLOCK?

ACE engine blocks are sold exclusively direct-to-consumer through our website. Same price for everyone — no dealer markups, no middlemen.