Atomic Barra Hi-Rev Valvetrain Package
Engineering Overview
SPEC-DOC
Atomic Hi-Rev Valvetrain Package
Marine Grade Punishment
When you are building a valvetrain for extreme high-RPM use, transient bursts of power aren't enough to prove reliability. You need sustained load. This exact valvetrain package has been proven in the Xplicit Racing Boat over the last few seasons. Running at 8600 RPM and 38 PSI for minutes at a time, a dozen times a race weekend, it survives an environment that destroys lesser components.
If this kit can survive the sustained, relentless pounding of boat racing, it will easily handle years of street driving, burnouts, drifting, and drag abuse.
The Friction Equation
High RPM creates immense heat and friction. We combat this by utilizing our HD Double Roller Rockers. The additional roller on the rocker tip virtually eliminates the side-loading forces on the tip of the valve, drastically reducing wear, friction, and stress on the valve guides. To offset the slight weight increase of these robust rockers, we utilize ultra-lightweight Titanium Retainers to keep the overall mass of the moving assembly to an absolute minimum.
💡 Expert Builder's Tip
Lessons from Tony Hearne — Head Preparer for the Xplicit Racing Boat:
When setting up the seats for these stainless valves, only stone the standard, uncut factory seats. You want to retain the maximum amount of material in the seat itself unless you are replacing it with an upgraded seat. While this leaves a tiny bit of flow on the table compared to aggressive cuts and large throat diameter, it does two critical things: it acts as a massive heat sink to draw destructive heat out of the exhaust valve, and it gives the seat the structural strength required to survive the relentless pounding of high RPM impacts combined with heavy spring pressures.
*While not strictly critical, for the absolute ultimate setup, Atomic upgraded valve guides and aftermarket seats are available separately.
Package Engineering
Hydraulic Stability
24x Anti-Pump Lifters
Features high-flow damping ability to reduce valvetrain noise and harmonics. Prevents the dreaded "pump-up" that holds valves open and destroys engines under hard limiters.
Timing Lockdown
Vernier Sprockets + VCT Delete
High lift and extreme RPM cause standard VCT units to wander. Locking the cams with billet Vernier gears ensures timing remains 100% true regardless of RPM.
Valve Control
Stage 3 or 4 Springs & Ti Retainers
High spring pressure requires weight reduction. Our Titanium retainers ensure the valve snaps shut without floating at 8600 RPM. We test and check EVERY spring for straightness and group them +-1lbs to minimise variation and harmonics.
📦 Kit Contents
- 12x Stainless Steel Intake Valves (+0.5mm Oversize)
- 12x Stainless Steel Exhaust Valves (+0.5mm Oversize)
- 24x Anti-Pump High Rev Hydraulic Lifters
- 24x HD Double Roller Rockers
- 24x High-Pressure Valve Springs (802 or 803 Spec)
- 24x Titanium Retainers
- 2x Billet Vernier Cam Sprockets
- 1x VCT Delete Kit (Plates & Internal Spigots)
- 24x Valve stem seals (standard height)
- 0x Collets - Reuse your factory collets unless damaged.
Compatibility Note
This package is designed to drop into standard Ford Barra DOHC cylinder head castings. The oversized stainless valves are compatible with standard factory valve seats (machining/stoning required to accept the +0.5mm diameter). EXTENDED HIGH LOAD USE APPLICATIONS REQUIRE SPECIAL ATTENTION. If you are circuit racing, drifting, or otherwise spending more than 10 seconds a time at high load then you must take care in removing minimal material from the factory valve seats. For additional safety replacing valve seats should be considered.
Suitability: Street, Drag, Drift, Burnout, and Marine applications.
