Arlen Ness Oval Stage 2 Air Cleaner

Modern Harley-Davidson motorcycles with Big Twin Milwaukee-Eight engines are factory-tuned with emissions and noise regulations in mind. One of the elements limiting the engine’s potential is the stock intake system, designed primarily for stable operation while meeting regulations rather than for maximum airflow.

The 2024 Street Glide is equipped with a Milwaukee-Eight 117 engine with liquid-cooled cylinder heads, while the engine is still primarily cooled by airflow and oil. Therefore, simply leaning out the mixture is not enough (the engine would overheat) - the amount of incoming air has to be physically restricted.

It is enough to look at the stock air filter to see how small the open filtering surface is, despite the huge housing, which acts as an air reservoir and a noise suppressor.

Almost all aftermarket intake systems use a larger filter element and a less restrictive intake tract. 

For our project, we chose the Arlen Ness Stage 2 Oval Air Cleaner. Its airflow capacity is probably excessive for a regular Stage 1 setup, but we liked its design and appearance.

The Stage 2 Oval name itself suggests that the filter is suitable for upgraded camshafts and higher RPM. There is also a version with a transparent window in the front cover instead of the filtering element, but those filters do not have "Stage 2" in their name.

On Touring models, this filter looks especially harmonious and matches the massive M8 engine very well.

The video shows the filter installation process in detail. To see comments for each stage, enable subtitles.

• 00:04 Stock Street Glide 2024 air filter.
• 00:20 Removing the stock air filter.
• 01:06 Milwaukee-Eight engine without the intake system.
• 01:19 Arlen Ness Stage 2 Oval Air Cleaner kit.
• 01:39 Installing the Arlen Ness Stage 2 Oval.
• 03:40 Arlen Ness Stage 2 Oval on the Street Glide 2024.

Overall, the installation is simple and does not require any fine adjustment or fitting, which is sometimes necessary with other intake systems.

The intake comes with a high-quality reusable fabric filter element. The manufacturer does not specify a fixed service interval or filter lifespan, as these depend on operating conditions. However, it recommends cleaning the filter as part of the motorcycle’s regular maintenance.

For comparison, K&N states an approximate service life of 50,000 miles or more for reusable fabric high-flow filters under normal operating conditions. 

• Unlike disposable paper filters, reusable fabric filters are designed for a significantly longer service life and can be reused after maintenance. 
• If you service such a filter yourself, it can be cheaper in the long run than regularly replacing disposable filter elements.
• Another good thing is that Arlen Ness equips its intake systems with black filters, because dirt and deposits are less noticeable on them than on red or white ones.

We have opened a discussion on the forum where you can discuss this topic.