<p> Need to vent your BMW engine but don't want to drill the valve cover? Look no further.  Rally Road has CAD designed a billet aluminum oil cap vent adapter to make this task simple. The oil cap easily replaces your stock oil cap, and includes an AN 10 port on the top to allow a low profile swivel fitting to be installed.</p> <p>The cap is machined on a 5-axis CNC from 6061-T6 aluminum.  The machined retainer bar and expanding assembly ring is made from 316 stainless steel as well as the AN10 swivel fitting.  The cap includes viton orings for an extremely long life.</p> <p>By using this cap design, you can leave the hose attached to your catch can and simply remove the cap to perform oil changes.  The adapter has a smooth rotation, while keeping a liquid tight seal.</p> <p>The cap fits all metal and plastic valve covers from M50, M52, S50, S52, M54, and S54.<br></p> <p>Included is (1) Oil Fill Cap and (1) AN10 swivel fitting as pictured.<br><br>Install Tip: Use a little oil to lubricate the rubber seat on the underside of the cap and press down when turning.  This will help it rotate into locking position.</p> <!---->