Yella Terra YT 6645 LS1 LS2 1.7 Ultralite shaft roller rockers

Yella Terra GM LS1/LS2 Ultralite 1.7:1 8mm Shaft-Mount Roller Rockers — YT 6645

$950.00
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Yella Terra YT 6645 LS1 LS2 1.7 Ultralite shaft roller rockers

Yella Terra GM LS1/LS2 Ultralite 1.7:1 8mm Shaft-Mount Roller Rockers — YT 6645

$950.00

Yella Terra’s Ultralite shaft-mount roller rocker system is a lightweight factory-replacement/street upgrade for GM LS1 and LS2 engines. This version uses a 1.7:1 rocker ratio with the factory-style 8 mm shaft mounting.

Ultralite design

  • Set of 16 full-roller aluminium rocker arms.
  • Supplier-rated to 400 lb maximum open spring pressure.
  • Approximately 50% less oscillating nose weight than the factory rocker system.
  • Oversize full-complement caged bearings and precision-ground trunnions are designed specifically for oscillating rocker loads.
  • Aircraft-grade extruded aluminium arms reduce moving mass and help dissipate top-end heat.
  • Hardened chromoly roller tips reduce valve-tip and guide wear.
  • Common-shaft inlet/exhaust mounting increases clamp footprint and valvetrain stability.
  • Maximum spring diameter: 1.437 in.
  • Hydraulic operation; not recommended for flat-tappet or solid-lifter use.

Clearance requirements

  • Yella Terra specifies a maximum recommended spring seat pressure of 380 lb for this Ultralite application.
  • Requires Yella Terra YT 5132 10 mm valve-cover spacer.
  • Due to variation in GM cylinder-head castings, localised head clearancing may be required. Clearance must be checked during installation.
  • Shaft centres must retain the applicable M8 mounting threads.

Installation: Verify pushrod length, rocker geometry, spring/retainer clearance and piston-to-valve clearance for the complete engine combination.

Product System

  • Engine Parts

Vehicle Fitment

  • Chevrolet Corvette C5 Ls1
  • Chevrolet Corvette C6 Ls2
  • Holden Commodore Ve Ls2
  • Holden Commodore Vt Vt Ii Ls1
  • Holden Commodore Vx Ls1
  • Holden Commodore Vy Ls1
  • Holden Commodore Vz Ls1
  • Holden Commodore Vz Ls2

Confirm chassis, engine, drivetrain and production-year compatibility before ordering.

Supplier Part Number

YT 6645

Built by Boost & Tune Support

BBT can assist with fitment review, installation, supporting modifications, configuration and calibration requirements where applicable.

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