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.
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