Designed for strength, built to race. No other rocker system compares with Yella Terra Platinum race series. Manufactured and assembled in Australia using the highest quality materials and componentry sourced locally and from the USA.
Our wide range of true ratios allows you to achieve high lift without relying solely on your camshaft… a trend many engine builders and racers alike are adopting to relieve the inertia on lifters and pushrods generated by aggressive and often violent ramp rates required to make big lift.
Proven bolt-on shaft design featuring heavy duty 7/16” and 10mm hardware for stability and durability well beyond the chequered flag.
Why Choose Platinum?
- Wide body arms for greater strength and resistance to deflection, extruded from aircraft grade aluminium for the highest RPM potential. Built to withstand 900lbs* max open spring pressure
- Oversize full-complement caged bearings designed for oscillating (rocking) loads, paired with oversize precision ground trunnions to reduce friction.
- Intricately balanced CNC billet arms ensuring vital valvetrain stability - focusing attention on the harmony of the entire engine.
- Single shaft bolt-on also available for cantered valve cylinder heads.
- Extruded from aircraft grade aluminium, perfect for dissipating excess top-end heat.
- Proven bolt-on shaft mount design that mounts both inlet/exhaust to common shaft, effectively increasing footprint and clamp load twofold without any further cylinder head modification.
- Various ratios available, catering for every camshaft grind. High ratios allow for additional lift on stock and aftermarket camshafts.
- Chrome moly steel hardened and ground roller tips of generous diameter (positively retained by internal circlip) preventing abrasion of valve tips and guides commonly seen with non-roller tip rockers. Allows for smoother, quieter operation Maintains lash and reduces necessary and tedious engine maintenance.
Tech Spec
PART NO |
YT 6640 |
BRAND |
PLATINUM |
APPLICATION |
RACE/STRIP |
MAX OPEN SPRING PRESSURE
|
900lbs |
MAKE |
CHEVROLET |
ENGINE |
LS1/LS2 |
MOUNTING STYLE |
SHAFT MOUNT |
ROCKER ARM RATIO |
1.7 |
STUD SIZE |
7/16" |
ADJUSTABLE/HYDRAULIC |
ADJUSTABLE |
ROCKER ARM STYLE |
FULL ROLLER |
ROCKER MATERIAL |
ALUMINIUM |
ROCKER ARM BODY STYLE |
STANDARD |
ROCKER ARM NUT STYLE |
CAPSCREW |
MAX SPRING DIAMETER |
1.437" |
INLET OFFSET |
NO |
QTY |
SET OF 16 |
NOTE |
DRILL & TAP 7/16" |
*Requires YT 5123 25mm valve cover spacer.
