Harley-Davidson Compression Release Machining

The Harley Twin Cam engine, in particular, benefits from raising the compression ratio. The resultant increase in cylinder pressure produces a noticeable gain in torque and throttle response, but can put extra load on the starter and battery.

Compression release discreetly installed in a Twin Cam cylinder head.

The installation and use of simple mechanical compression releases in the cylinder heads bleeds off this extra cylinder pressure when starting, and negates the need for the often problematic and expensive, after market starter motors and batteries.

Using our large mill and a fixture, we accurately position and machine each pair of heads to accept these useful and reliable devices.

Harley-Davidson Twin Cam cylinder heads are bolted to a rigid machining fixture on our milling machine. This ensures accurate positioning and a good finish.

A small batch of Twin Cam heads machined for mechanical compression releases.