Description

FIRST ORDERS OPEN EST. LATE MARCH
Atomic H260 Cast Iron Barra Block

The Industry-First Aftermarket Barra Casting
Please note: Information subject to update as production finalises.

The New Foundation

For decades, the limit of the Barra has been the block itself. While the factory design is good, the castings are VERY inconsistent with variation in wall thickness of up to 2mm in a single block 1000HP+ builds start to face cylinder distortion and eventually cracking. Whilst this was the main thing we wanted to address, there are dozens of other smaller features that bring this block up to the Atomic standard. Based on approximately 1000 Barra builds, hundreds of dissassemblies, failures and breakages, and long living well put together recipes, we've made this block with a deep knowledge of what makes a Barra roar

?? DID YOU KNOW?

This block uses "Murray's Magic Dust". Our proprietary H260 Base Iron blend offers an estimated +40% tensile strength increase over OEM grey iron. Stronger material combined with a 50% increase in min. cylinder wall thickness vs Factory, plus added ribbing and support structures, make for a far stronger and more stable block. Better ring seal, better bearing stability, better head gasket seal.

THE ATOMIC OPTION

The Atomic Cast Block is a direct OEM+ replacement that solves these issues. With a Siamese Bore design for rigidity, Stepped Cylinder Walls (min 5.5mm thickness), and a Thicker Deck, it is the ultimate foundation for everything from a reliable street car to a 2500HP+ drag weapon.

Siamese Bores. H260 Iron. 2500HP Capable.

Engineering Highlights

H260 "Magic" Iron

Special blend H260 base iron with proprietary additives. Offers +40% tensile strength vs OEM for extreme cylinder pressure containment, reducing twisting during launching and high torque scenarios.

Siamese Bores

Cylinders are connected (Siamese) rather than having a gap, massively increasing rigidity. Allows for consistent ring seal at high boost. 60% increase in bore thickness over factory.

Cooling System

Features a revised pump impeller cavity with added flow vane to assist coolant flow at idle. Internal cooling ribs support bores and increase surface area. "Grout Filled" and "dry deck" options available.

Priority Oiling

Revised oil gallery size and routing. Additional turbo feed outlet on exhaust side plus feed/sensor ports on intake side. Dual dipstick ready. Revised oil filter boss for easy relocation.

High Rod Clearance

Bore skirts are pre-relieved for increased stroke and aluminium rods. Accepts all OEM brackets, heads, and accessories.

Billet Main Caps

Designed to support Standard Style or Atomic Wide-Style 4140 Billet Steel caps. Threaded for M12 or M14 tool steel studs to ensure zero cap walk.

Precision engineered for maximum rigidity.

Technical Specifications

Feature	Specification
Standard Bore Size	92.25mm (Suits Atomic Pistons) Other sizes specify at purchase
Bore Range	Min: 85.0mm (12.5mm thickness) Rec: 92.3mm (5.5mm thickness) Max: 95.0mm (3.5mm thickness)
Min Wall Thickness	5.5mm @ Skirt Base (vs 3.5mm OEM)
Deck Height	Standard OEM Height
Deck Thickness	15mm (Massive increase for rigidity)
Pan Rail Thickness	22mm
Bare Weight	66kg (Factory = 63kg)
Main Stud Options	M12x1.5 (Standard) or M14x1.5 (Extreme)

Block Tiers & Power Ratings

Street / Performance

Rating: Guaranteed 1500HP
Cooling: Full Water Jackets with -16 ORB plugs
Use Case: High HP Street, Roll Racing, Circuit/Endurance

Pro Drag (Filled)

Rating: 2500HP+
Cooling: Part-Filled dry-deck down or solid casting
Use Case: Crazy Street, Roll Racing, Dedicated Drag Racing, Methanol

Comprehensive Change Log

Modifications and improvements over OEM design

Material & Strength

Material: Proprietary H260 "Magic" Iron blend.
Strength: +40% tensile strength increase over OEM grey iron.
Structure: Added ribbing and support structures for maximum rigidity.
Mass: 66kg Bare Weight (Heavy-duty casting).

Bore & Deck

Bore Design: Siamese Bores (connected cylinders) for max rigidity.
Wall Thickness: Min 5.5mm @ Skirt Base (60% increase over OEM).
Deck Thickness: Massive 15mm thick deck surface.
Sump Rail Thickness: 22mm without changing bolt positions.
HG Interface: Revised head gasket interface to reduce leaks/splits (compatible with all existing gaskets).
Fitment: Bore skirts pre-relieved for stroker/aluminium rod clearance.
Bore Size Range: 85mm-95mm recommended limits (103.6mm bore spacing).

Structure & Cooling

Increased Ribbing: Thickness and paths increased for stability.
Custom Bellhousing: Patterns available upon request.
Enlarged Crankcase Cross Vents: For reduced pumping loss.
Cooling: Internal cooling ribs to support bores.
Water Flow: Revised pump impeller cavity with added flow vane.
-16 ORB Water Plugs: To allow for motorsport grade connections.

Oiling & Hardware

Exhaust Side Port: Added specifically to make turbo oil feeds neater and easier.
Main Gallery Ports: Additional ports added for feeds/sensors.
Main Journal Oiling: Improved to increase flow and distribution.
Improved Drains: Better venting for quicker drainage during acceleration.
Filtration: Revised oil filter boss for easy relocation.
Head Studs: Threaded deeper. Standard M12 or Extreme M14.
Main Caps: Supports standard and Atomic Wide-Style Billet caps.
Dipstick: Dual dipstick ready (Front or Rear sump).

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