Barra Horsepower Guide

The Blueprint to Building a Bulletproof Engine

Taking the guesswork out of engine building. Use this matrix to identify the exact Atomic Performance components required to safely support your horsepower goals. Whether you are building a reliable daily driver or a 2000hp+ drag monster, matching the right hardware to your target power level is the key to longevity.

Component Category	Street / Mild Up to 650 HP (500kW)	High Performance 650 HP - 1000 HP	Extreme / Track 1000 HP - 1500 HP	Outlaw / Drag 1500 HP - 2000 HP+
Pistons	Hypatec Cast Pistons High-silicon cast alloy with coated skirts. Excellent OEM+ replacement.	Atomic ICON Forged Pistons 4032 Forged. Quiet operation, no piston slap. Perfect for street turbo setups.	Cosworth F1 Series Pistons 2618 Aerospace Alloy. Xylan coated skirts, 6 internal support struts.	Cosworth F1 Series Pistons 2618 Alloy. Capable of handling 9 tonnes of combustion force. Polished Crowns
Connecting Rods	Superleggera Billet Rods Lightweight 722g design. CA625 bolts standard.	Superleggera Billet Rods Reduces reciprocating mass while holding up to 1000hp.	FatRod Billet Conrods 13% wider, 14% thicker H-beam. Pressure fed pin oiling.	FatRod (or Destroker Kit) Zero recorded failures since 2004. Tested to 8000+ g's. CA625 Bolts Mandatory
Head Studs	12mm H13 Tool Steel Studs Direct replacement for factory bolts. Prevents head lift.	12mm H13 Tool Steel Studs 270,000 psi tensile strength. Cold rolled threads.	12mm H13 Tool Steel Studs Torqued to 100+ ft-lbs with HD oversized washers.	14.3mm H13 Tool Steel Studs Requires block & head machining. Ultimate clamping force. Machining Required
Head Gasket	OEM or Atomic MLS-D Standard multi-layer steel replacement.	Atomic MLS-D Gasket Diesel-style folded fire ring prevents layer shuffling under boost.	Atomic MLS-D Gasket Requires < 30 RA deck finish for perfect sealing.	Copper Fire Ring Gasket 1mm Copper. Recesses machined into block/head for wire O-rings. Machining Required
Bottom End Support	Factory Main Caps / Factory Sump	10mm Billet Main Girdle Ties main caps together. Fits under standard un-modified sump.	10mm Girdle + Billet Main Caps 4140 Steel caps prevent main tunnel distortion.	16mm Race Girdle + Billet Caps Maximum rigidity. Requires sump spacer or clearance modification. Atomic Cast Block Recommended
Oiling System	Oil Pump Rebuild Kit Nitrided billet gears & CRMO backing plate in OEM housing.	Race Series Alloy Pump Fully blueprinted, hand-ported alloy housing with billet internals.	Stainless Steel Oil Pump Eliminates thermal expansion issues. Consistent gear clearances.	Stainless Steel Oil Pump High-Pressure non-VCT version. Pair with Big Ears Sump.
Timing & Harmonics	OEM+ "Pink Bits" Chain Standard tensioner, Powerbond Balancer.	HD Timing Chain + ATI Balancer Essential to handle increased loads from HD valve springs.	Billet Tensioner + Crank Bolt Kit Mechanical locking tensioner. Billet crank bolt with Nord-Lock.	Crank Dowelling Jig Kit Dowelled crank and flexplate to prevent shearing under launch.

Engine Building Packages

Don't want to spec it out yourself? We offer complete Long and Short engines tailored to these exact tiers. From the Series 550 (1000hp street) to the 698 GT-A and the ultimate cast-block Mega Barra 2000 GT-A, our engines are dyno-tested, clearanced, and delivered ready to drop in.

⚠️ Important Build Variables

Horsepower is only one metric. RPM, Torque, and Application (e.g., Drag vs Circuit) drastically change part requirements. For example, sustained 8500+ RPM requires Anti-Pump Lifters and Double Roller Rockers regardless of horsepower output. Always consult with your engine builder or contact Atomic Support for specific advice.