Atomic Performance Engines represent 20 years of continuous improvement and updates to how we build Barras. We've built close to 1000 Barras since 2004 and we've learnt what's needed to keep them quiet, tough and powerful! We catalog and record everything on your build so you end up with a record of the bearing clearances, ring end gaps, cold and hot compression, oil pressure curve etc. We spend a lot of time on preparing, cleaning and inspecting parts and we stand behind the quality of our work. We take pride in our work and own up to our mistakes so that you don't have to wear them. We've all been customers of different shops and we treat our customers to the same service level we would expect if we were in your position.

We have 4 main engine specs to cover OEM+ builds all the way through to 1500+hp monsters. For more customised or higher power builds we work with you to design the engine around your goals and setup. We have an excellent team and network of talented engineers who can help us create whatever you need.

For more detailed specs of our main engines, keep reading! If you have questions or want more info, contact us via the website to chat Barra!

Atomic 475 Engine Kit: The Ultimate Foundation for Your Project

The Atomic 475 Engine Kit is the perfect starting point for any performance-minded enthusiast seeking to build a robust and reliable Barra engine. Engineered as a significant step up from a stock rebuild, this kit provides a rock-solid foundation that can handle a massive increase in power, while retaining the durability required for a high-performance street application. We've meticulously selected each component to ensure a perfect balance of strength, performance, and value. The heart of this kit is our market-leading Superleggera connecting rods, which are machined from aerospace-grade billet steel to deliver an exceptional strength-to-weight ratio. These are paired with a set of durable cast Hypatec pistons, providing a robust foundation that can handle significant power increases. To ensure your engine's vitals are secure, the kit features a rebuilt OEM oil pump with ported housing, billet gears and backing plate for upgraded reliability. The Atomic complete timing chain kit (306620-K-C) ensures perfect synchronisation and is built with heavy-duty components to eliminate stretch, excess wear and unstable timing. A full ACL RACE bearing kit and an ATOMIC MLS-D full gasket kit guarantee a precise fit and a leak-free seal. Finally, the Stage 2 valve springs - 80-90 lbs, provide the essential valvetrain stability needed for high-performance applications and a boost and rpm upgrade over standard.

Finer Details

Our professional engine preparation goes far beyond a simple rebuild. We meticulously deburr the block for perfect oil flow and pressure test every cylinder head to find hidden cracks, ensuring a flawless foundation. By setting our optimized clearances, we guarantee a motor that not only runs quietly and with great oil pressure but also handles the high RPMs you will throw at it, leading to a smooth, worry-free run-in that saves you time and prevents headaches down the road.

Specifications: Atomic 475 Engine Kit

• Rods: Superleggera
• Pistons: Hypatec Cast
• Bearings: ACL RACE
• Gasket kit: ATOMIC MLS-D
• Timing chain kit: Atomic Complete timing chain kit
• Oil Pump/rebuild kit: Rebuilt Alloy Pump with billet gears and backing plate
• Head studs: 12mm Tool Steel
• Valve Springs: Stage 2 (80-90 lbs)
• Valves: New OEM turbo
• Balancer: OEM
• Girdle: OEM
• Lifters: OEM
• Cams: OEM FG
• Titanium Retainers: Optional
• Vernier Gears: No
• Additional Engine Parts: All necessary small components and consumables to complete your build, including a fresh windage tray, brass plugs, Welch plugs, a filter, a bolt kit, and all required collets, seals, and retainers. It also includes an OEM timing cover, cam cover, and sump, as well as spark plugs, oil, water pump, pick up tube, and a dipstick.
• Block: Prepared to a 475 specification by our machinist, KC. Services include a bore, hone, deck, skim, and minor regrind. The block is also deburred and painted.
• Head: A Stage 2 head, also prepared by machinist KC. Services include a skim and minor regrind. We use fresh valve stem seals, collets, and retainers. The head does not have porting and utilizes OEM intake valves and turbo exhaust valves for OEM Like driveability.
• Crank: Prepared to a Stage 1 specification. Services include a check, test, polish.

Atomic 550 Engine Kit: The High-Performance Stepping Stone

The Atomic 550 Engine Kit is engineered for the serious enthusiast looking to push beyond standard performance. This kit takes all the strengths of our 475 platform and elevates them with critical upgrades designed for increased boost and power. It's the ideal choice for those targeting a high-output street or track application.This package features a significant upgrade to ICON Forged pistons, providing superior strength and durability. The reliable Superleggera conrods are retained, while the entire oiling system is enhanced with a robust steel oil pump for uncompromised lubrication under extreme conditions. The Stage 3 valve springs are designed to handle the higher revs and increased pressures of a more powerful engine, making this kit a true performance foundation.

Finer Details

This kit is built to withstand extreme forces. We start by hand-selecting a thicker block that receives additional deburring to accommodate higher strain and loads and ensure your sump doesn't run dry! This is supported by a robust 10mm girdle for superior main cap support and a full steel oil pump to ensure consistent oiling under all conditions. To handle high RPM and boost, we include anti-pump lifters and upgraded stainless steel valves that are better suited for managing heat from extended high power running. All of these meticulous upgrades work in unison to provide a balanced package that you can trust to reliably handle 1000hp with the optional ATI balancer.

Specifications: Atomic 550 Engine Kit

• Rods: Superleggera
• Pistons: ICON Forged
• Bearings: ACL RACE
• Gasket kit: ATOMIC MLS-D
• Timing chain kit: Atomic Complete timing chain kit
• Oil Pump/rebuild kit: Steel oil pump
• Head studs: 12mm Tool Steel
• Valve Springs: Stage 3
• Valves: Stainless +0.5mm
• Balancer: Powerbond (upgrade to ATI highly recommended)
• Girdle: 10mm
• Main Studs: OEM
• Torrington Bearing: Optional
• Billet Main caps: No
• Lifters: Anti-pump
• Cams: OEM FG. Stage 3 or 4 optional upgrade
• HD Roller Rocker: Optional
• Titanium Retainers: Optional
• Cam gears: VCT
• Additional Engine Parts: All necessary small components and consumables to complete your build, including a fresh windage tray, brass plugs, Welch plugs, a filter, a bolt kit, and all required collets, seals, and retainers. It also includes an OEM timing cover, cam cover, and sump, as well as spark plugs, oil, water pump, pick up tube, and a dipstick.
• Block: Prepared to a 550 specification by our machinist, KC. Services include a bore, hone, and deck. The block is also deburred and powder-coated.
• Head: A Stage 3 head, also prepared by machinist KC. Services include a skim and a minor regrind. It utilizes stainless +0.5mm intake and exhaust valves, standard seals, standard collets, and black retainers. The head does not have porting.
• Crank: Prepared to a Stage 2 specification. Services include a check, test, polish, and balance. The crank also includes rocker fittings.

Atomic 698 Engine Kit: The Ultimate Performance Street Engine

The Atomic 698 Engine Kit is the definitive package for those seeking to build a high-horsepower street or weekend race car. This kit represents a significant leap forward, designed with premium components and professional services to support extreme power levels with unwavering reliability. This package features the gold standard in forged pistons: Cosworth Forged Pistons, renowned for their superior strength. The package includes a high-end ATI balancer for perfect valvetrain stability at high RPM. This kit also introduces a professionally hand-ported cylinder head and a Stage 3 crank, ensuring that the entire engine is optimized for peak performance from intake to exhaust. The 698 is a true turn-key solution for a serious performance build. Finer Details The 698 engine is engineered to breathe easier and perform harder. We professionally hand-port the cylinder head, meticulously shaping the ports to increase both flow and velocity, which results in a significantly more responsive and torquier engine. To match this increased power, we hi-flow the rear main bearings to proactively prevent oil starvation under extreme conditions. Finally, the choice between the recommended Stage 3 or Stage 4 cams allows you to tailor the engine's performance to your specific needs, whether for a high-end street build or a dedicated race car.

Specifications: Atomic 698 Engine Kit

• Rods: Superleggera
• Pistons: COSWORTH Forged
• Bearings: ACL RACE
• Gasket kit: ATOMIC MLS-D
• Timing chain kit: Atomic Complete timing chain kit
• Oil Pump/rebuild kit: Steel oil pump
• Head studs: 12mm Tool Steel
• Valve Springs: Stage 4
• Valves: Stainless +0.5mm
• Balancer: ATI
• Girdle: 10mm
• Main Studs: OEM
• Torrington Bearing: Optional
• Billet Main caps: Optional
• Lifters: Anti-pump
• Cams: Stage 3 or 4
• HD Roller Rocker: Optional
• Titanium Retainers: Optional
• Cam gears: VCT
• Additional Engine Parts: All necessary small components and consumables to complete your build, including a fresh windage tray, brass plugs, Welch plugs, a filter, a bolt kit, and all required collets and retainers. It also includes an OEM timing cover, cam cover, and sump, as well as spark plugs, oil, water pump, pick up tube, and a dipstick.
• Block: Prepared to a 698 specification by our machinist, JS. Services include a bore, hone, and deck. The block is also deburred and powder-coated.
• Head: A Stage 4 head, prepared by machinist JS. Services include a skim, minor regrind, and professional hand porting. It utilizes stainless +0.5mm intake and exhaust valves, standard seals, standard collets, and black retainers. The kit also includes new seats and guides.
• Crank: Prepared to a Stage 3 specification. Services include a check, test, grind, polish, heat treat, and deburr. The crank is also balanced and includes rocker fittings.

Atomic 998 Engine Kit: The Ultimate Race Engine

The Atomic 998 Engine Kit is the pinnacle of Barra performance—a no-compromise package built for extreme horsepower, maximum reliability, and a winning edge on the track. Every component in this kit is a top-of-the-line upgrade, meticulously selected to withstand the most violent forces of a high-boost, high-RPM race engine. This package features the bulletproof Fatrod connecting rods and Cosworth Forged Pistons, the most robust combination available. The block is strengthened with14mm head studs, Atomic billet main caps, and an Atomic Tool Steel main stud kit. The cylinder head features professional race hand porting, and the OEM Race crank is fully prepared with all the necessary race-spec services. If you're building to win, the 998 is the only option.

Finer Details

The 998 engine is engineered for a level of performance where every detail matters. We start by choosing only the best raw materials, meticulously inspecting and selecting blocks with a1 in 10 thickness and the straightest cranks. The crankshaft itself is deburred, and we port the oil filter passage to ensure flawless oiling. Every clearance and pressure is optimized for high-load, 1500hp running. This unwavering commitment to engineering for the extreme results in an engine that is equally at home on the street as a half-grout machine or as a highly engineered 1200kW circuit weapon.

Specifications: Atomic 998 Engine Kit

• Rods: Fatrod
• Pistons: COSWORTH Forged
• Bearings: ACL RACE
• Gasket kit: ATOMIC MLS-D or Copper Fire Ring
• Timing chain kit: Atomic Complete timing chain kit
• Oil Pump/rebuild kit: Steel oil pump
• Head studs: 14mm Tool Steel
• Valve Springs: Stage 5
• Valves: Stainless +0.5mm
• Balancer: ATI
• Girdle: 10mm
• Main Studs: Atomic Tool Steel
• Torrington Bearing: Optional
• Billet Main caps: Optional
• Lifters: Anti-pump - solid option
• Cams: Stage 4+ or 5+
• HD Roller Rocker: Yes
• Titanium Retainers: Optional
• Cam gears: Vernier
• Additional Engine Parts: All necessary small components and consumables to complete your build, including a fresh windage tray, brass plugs, Welch plugs, a filter, a bolt kit, and all required collets, seals, and Titanium retainers. It also includes an OEM timing cover, cam cover, a Big ears sump, as well as spark plugs, oil, water pump, pick up tube, and a dipstick.
• Block: Prepared to a 998 specification by our machinist, JS. Services include a bore, hone, deck, and tunnel hone. It also includes the option to be tunnel bored if billet caps are selected and can be grout filled as an option. The block is also deburred and powder-coated.
• Head: A Stage 4+ 5+ head, prepared by machinist JS. Services include a skim, a full setup, and professional race hand porting. It utilizes stainless +0.5mm intake and exhaust valves, low-profile seals, and HD collets. The head also comes with Titanium retainers.
• Crank: Prepared to a OEM RACE specification. Services include a check, test, grind, polish, heat treat, and deburr. The crank is also fully doweled and includes a flexplate, 14mm headstuds, and rocker fittings.