Atomic 550 GT-A Long Motor – Ford Barra DOHC | Street Spec | 800hp atw Capable

Description:
The Atomic 550 GT-A delivers the ultimate blend of streetable refinement and drag-ready strength. Designed for customers chasing up to 800hp atw on a reliable and quiet long motor, the 550 GT-A bridges the gap between factory drivability and serious performance.

It comes equipped with our legendary Superleggera billet conrods, custom 2618 Atomic Icon forged pistons, and our race-proven FULL Steel oil pump with billet gears — all precision-clearanced and test-run in-house for guaranteed performance.

As featured in the Keep it Reet 1000hp atc Territory build

? Key Features

? Block & Foundation

• Ultrasonically tested Ford Barra thick-wall block
  • Selected for maximum structural integrity and wall thickness
  • Deburred and enlarged oil drain paths

? Pistons & Rotating Assembly

• Atomic custom 2618 forged pistons by Icon
  • Coated skirts, quiet crown geometry, 4-valve reliefs
  • Ideal for sustained high boost and street duty

• Atomic Superleggera H-beam billet conrods
  • Direct oil feed to piston crown and gudgeon pin
  • CA625 rod bolts standard for high RPM reliability

• OEM crankshaft
  • Journals linished, oil holes chamfered, seal track cleaned

Optional upgrade to FatRod conrods for extreme builds (1500hp+)

? Cylinder Head & Valvetrain

• Ported performance cylinder head
  • Improved flow and velocity for top-end and low-speed torque

• All-new valves, upgraded valve springs, and retainers

• Optional Atomic camshaft, rocker, and lifter upgrades available

? Oiling & Timing

• All-steel high-volume billet oil pump
  • EDM-cut billet gears, high-flow capacity, steel backing plate

• Complete Heavy-duty timing chain kit with new OEM Ford tensioner
  
  

? Blueprinting & Testing

• Precision-assembled to Atomic clearance specs
  • Main bearing, piston-to-wall, ring gaps, lifter preload all measured

• Test-run in-house with vitals recorded
  • Oil pressure, lifter bleed, ring seal, and chain tension verified
  • Detailed build sheet and report supplied

?? What’s Included

• Fully assembled Atomic 550 GT-A Long Motor

• Powder-coated rocker and timing covers (colour of your choice)

• Brass Welch plugs

• NGK spark plugs, Ford oil filter, 14L 15W/40 run-in oil

• Gasket set, Atomic merch pack

• Torque specs, clearance report, run-in guide

• 12-month conditional warranty for street/track use

?? Optional Upgrades

• 14mm head stud conversion with CNC drill & tap

• Atomic ATI Balancer kit (required to run reliably above 550kw at the crank)

• Adjustable vernier cam gears

• VCT delete spigots and block-off plates

• Titanium retainers, and HD rockers

• Big Ears sump kit

• Torrington thrust bearing

• Fire-ring head gasket kit
  

Atomic 550 GT-A Engine Package: Engineered for High-Performance

The Atomic 550 GT-A engine package represents a comprehensive upgrade for your Ford Barra engine, designed to deliver substantial power gains and enhanced reliability for demanding street and track applications.

Key Components and Features:

• Ultrasonic Tested Block: The foundation of the 550 GT-A is a thick-wall Barra engine block, carefully selected and subjected to ultrasonic testing to ensure structural integrity and absence of defects. We match blocks to engine spec to make sure you get a block that supports your power goals.

• Atomic Forged Pistons: are custom designed by Atomic and made by Icon pistons to be a hugely strong yet quiet piston suitable for upto 1000hp atc. with low friction coated side skirts and noise reducing geometry around the crown and skirt we are able to have a 2618 alloy forged piston that isn't noisy when the engine is cold. The structural features within the piston provide superior strength and durability and help the piston to withstand high cylinder pressures and temperatures generated by sustained load. So whether you're giving it a squirt here and there, roll racing every week or chasing times, these pistons will be able to handle it.

• Atomic Superleggera H-Beam Forged Billet Conrods: Some people call them billet, some call them forged so we've just called them both! They're made from steel, they have never been broken by anyone so far (that we know of!) and they're the only Barra rods to have a direct oil feed to the gudgeon pin and piston crown. This has a huge benefit to piston cooling and wrist pin lubrication both of which increase durability and detonation resistance.

• Prepped Crankshaft: Every crankshaft is inspected and measured by Atomic before being prepped to get the journals linished and oil holes chamfered. We clean up the seal track to ensure good sealing and make sure the crank is free from defects.

• Performance Cylinder Head: The cylinder head is ported for improved airflow AND increased velocity. This not only makes the cylinder head flow more at high power and boost but also improves the low end torque and response! We use all new valves, upgraded valve springs, and new retainers for enhanced high-RPM capabilities. For those looking to push the motor we can upgrade cams, lifters, rockers for a higher redline.

• High-Volume Oil Pump: An all-steel, high-volume oil pump provides increased oil flow and pressure to maintain critical lubrication and cooling under demanding conditions.

• Precision Clearancing and Assembly: Each 550 GT-A engine package undergoes meticulous assembly by our skilled technicians, including precise clearancing of critical components to ensure optimal fit and function.

Technical Specifications:

• Power Output: Capable of handling 1000hp horsepower with appropriate supporting modifications.
• Applications: Suitable for high-performance street use, track days, and various motorsport applications.
• Compatibility: Available for both SOHC and DOHC Ford Barra engines (BA-FG). Note: SOHC applications may require modification for oil pump clearance.

Benefits:

• Increased Power and Torque: Delivers significant gains in horsepower and torque throughout the RPM range.
• Enhanced Durability: Engineered to withstand the rigors of high-performance use.
• Improved Reliability: Reduces the risk of engine failure under stress.
• Precision Engineering: Meticulous assembly and quality components ensure optimal performance and longevity.

Contact Atomic Performance Products:

For detailed specifications, pricing, and to discuss your specific requirements, please contact our team directly.

Atomic 550 GT-A is a high performance street engine that can handle nearly 900hp. It's very smooth and quiet but able to stand up to punishment. These can be optioned with 14mm head studs to keep the cylinder head down reliably around 1000hp. We test run every engine in house on a test rig and we record all measurements and provide them. We can ship worldwide in our custom made wooden engine crates.

Designed for customers who are looking at making around V8 Supercar power levels (without the $250,000 engine bill!) the 550 GT-A fits the bill nicely. As a more robust version of the StreeTorquer Series engines, the 550 GT-A was only released in 7/2022 due to customer demand for an engine that fits the important balance of serious power and affordability. The 550GT-A fills the bill nicely.

Starting with an ultrasonic tested thick-wall block, we add such components as our own custom forged pistons with 4 valve reliefs, our legendary H-Beam oil feeder conrods, a prepped crank and cylinder head, new valves and performance valvetrain, an all steel oil pump followed by precision clearancing and assembly are only a few of the features that make up the 550 GT-A package.

Every Atomic built engine is measured and clearanced by an experienced engine assembly specialist to tight tolerances developed by Atomic since 2004. We love paperwork (unusual right!) so your whole build is thoroughly documented and stored in our system along with your order number. That means that even 5 years later we can tell you what clearances you had, the ring gaps, what oil pressure your engine had on idle, how thick the bores are.... etc. After assembly we test run your engine on our engine test bench for several hours. We monitor vitals such as lifter bleed, ring seal, tensioner engagement, cold through hot oil pressure to make sure your engine is running as it should. When we're done we will give you a care package with gaskets, merch, build sheet with all clearances etc.

Having rebuilt well over 500 Barra engines since 2004 we're not mucking around. We have a process, we follow it and we test it so you can send it!