Automatic Compression Release (ACR) valves reduce the strain of starting your high performance motor by reducing cylinder compression - automatically! The engine is easier to turn over resulting in less wear on your starter and battery. After start, the ACR valves close to restore full compression.

Key Features

• ACR can be installed on stock or Screamin' Eagle® Performance cylinder heads for all '07-later Twin Cam equipped models
• Install requires machining to be performed by a competent machinist using the Screamin' Eagle® Automatic Compression Release Fixture Kit P/N 94648-08 (sold separately)
• Installation requires separate purchase of model specific ACR Wiring Harness

Fitment

Fits '07-'17 Twin Cam-equipped models. Can be used with Original Equipment or Screamin' Eagle® Cylinder Heads. Does not fit with Twin-Cooled engines.