Valve Cover Breather
2003-2004 Mustang Cobra, 2007 & Newer Shelby GT500, Mercury Marauder
An Original Metco Motorsports Design!
This valve cover breather assembly replaces the original oil fill cap found on the driver's side valve cover on the supercharged Cobra and Shelby GT500 applications.
The base of the breather is CNC-machined from billet aluminum for a precise fit, and the included silicone O-ring is specially designed to prevent seepage at the base of the filter. The filter base is microfinished for surface protection and good looks, and is easily hand-polished to a mirror-like appearance. The removeable filter element is a high-quality reusable unit from S & B Filters, and the filter is securely retained to the filter base by a specially-machined retention groove in the top of the filter base.
The purpose of this valve cover breather is to vent unwanted accumulation of pressure in the crankcase, and to provide maximum circulation of ambient air in the crankcase to reduce oil temperatures. The installation of this breather will contribute to increased engine oil life and reduce the possibility of failed engine seals resulting from excessive crankcase pressure. This breather will reduce the effectiveness of the vehicle's PCV system, and it is not emissions-legal.
The included check valve will allow the breather to vent any crankcase pressure that accumulates, but it will not allow ambient air to be drawn back into the engine through the breather under high-vacuum conditions. This valve is beneficial for applications that retain a valve cover vent line, or applications with a very sensitive (or aggressively-lean) PCM calibration.
Note: This breather stand is also available with a male #10AN connection at the top instead of the provision for the breather element. This configuration is designed for use in a custom crankcase evacuation system or for use with a vacuum pump. Please see Metco Motorsports PN MBR0004-10AN, listed elsewhere in this section.