Miata 10AN Vented Valve Cover

This is the same vented valve cover setup I run on every engine I build and every car we modify at the shop. It's an OEM BP valve cover for the NA and NB Miata, reworked for proper crankcase ventilation.

The internal passages are drilled out to 3/8", and the driver side port is opened up to 1/2" to match the inside diameter of a 10AN line. Two 10AN bungs are welded on the outside, copper oil scrubbers go inside the baffling, and the cover is sealed back up.

If you choose powder coating, the cover is fully taken apart before coating, then cleaned and put back together afterward so no blasting media is left in the baffles. Powder coat is available in any Prismatic Powders color. Email me the color code after you order. The raw finish is cleaned only where it's welded, which means if you send me a painted valve cover and aren't getting it powder coated, it will be sanded down around the bungs only and will require you to either strip it the rest of the way, or repaint it to make it look consistent again.

You can send me your valve cover to modify, or I can supply one from the cores I keep on hand, with a refundable core charge: $100 for NA6, NA8 and BP4W covers, and $150 for VVT covers.

Lead time is about one week for raw and about two and a half weeks for powder coated.