S58/B58 Billet Oil Cap with ORB/AN adapter

Our S58/B58 Billet Oil Caps are now in stock and ready to ship.

Over the past several months, we’ve dedicated countless hours to solving an issue we’ve seen repeatedly with many aftermarket billet oil caps: oil leakage under boost when using ORB/AN adapters.

We’ve had numerous enthusiasts reach out after discovering their engine bays covered in oil, often believing it was simply the price of making big horsepower. The common response across forums has been, “That’s just how these engines are.”

We disagree.

The issue isn’t horsepower—it’s engineering.

Many products on the market are designed with manufacturing cost as the primary objective. Simplified designs, omitted features, and reduced machining time help lower production costs, but often come at the expense of performance and reliability.

At NRW Design, our philosophy has always been different.

We engineer the best product possible first. The manufacturing cost is simply what it takes to build it correctly. We’d rather invest a few extra dollars into every part knowing it performs exactly as intended than compromise quality to meet a price point.

So what makes our oil cap different?

Our billet oil cap features an internally baffled design that prevents oil from having a direct path out of the cap under high crankcase pressure. Combined with precision CNC machining, tight manufacturing tolerances, and rigorous quality control, it delivers the sealing performance enthusiasts expect from a premium product.

We’re so confident in its performance that we back it with a money-back guarantee. If our oil cap leaks under normal intended use, we’ll refund your purchase—no questions asked.

That’s how strongly we stand behind our engineering.

Machined from 6061 billet aluminum, designed for both performance and appearance, and proudly made in the USA, this is an oil cap built to perform—not simply to look good.

At NRW Design, we don’t cut corners. We solve problems.