100mm Billet 10AN Turbo Drain Oil Flange — Small-Frame

Stop fighting with leaky cast flanges. This 100mm billet 10AN turbo drain flange small frame fitment from BSI Inc. is precision-machined to give your small-frame turbo build a clean, high-flow oil return you can trust.

Features & Benefits

• Billet construction — Machined from solid billet for a flatter, more consistent sealing surface than the cast flanges that come stock on most small-frame turbos. Less distortion, fewer leaks, longer service life.
• 38mm (1.50") bolt centre — Designed to suit small-frame turbocharger bearing housings, including T3, T4, GT28, GT30, and GT35 class units. Bolt centre is measured from the centre of one drain pad bolt hole to the centre of the other. Fits journal-bearing and ball-bearing turbos alike.
• 100mm (3.94") drain length — The 100mm figure is the length of the drain, meaning how far the drain body stands off the flange face before your hose connects. It is the longest of three lengths, giving you reach past compressor housings, actuator brackets, and other obstructions common on small-frame installs. Also available in 35mm (1.38") and 65mm (2.56").
• 10AN male port — The full-sized 10AN fitting outlet supports high-flow oil return, keeping your drain line running freely and your bearing housing clear of oil pooling.
• Precision-machined sealing surface — Every face is machined to a tight tolerance so your drain gasket or O-ring seats properly and holds under real operating conditions.
• Direct upgrade over OEM cast — Drop this in where a stock or cast drain flange would go and immediately step up to a part built for performance builds — gas or diesel, street or track.
• Made in Canada by BSI Inc. — Machined domestically and ships from Canada, so North American builders get a quality billet part without the brokerage fees, border delays, or currency conversion headaches that come with importing from US-based competitors.

Upgrade your oiling system the right way — one precision part at a time.

Not sure which drain you need? See the turbo oil drain guide for bolt centre measurement, length selection, and full sizing charts in metric and US standard.

FAQ

What turbochargers is this 100mm billet 10AN turbo drain flange designed for?

It is designed to suit small-frame turbocharger bearing housings with a 38mm (1.50") bolt centre, including T3, T4, GT28, GT30, and GT35 class units.

What does the 100mm refer to?

100mm (3.94") is the length of the drain, meaning how far the drain body stands off the flange face. It is the longest option and is chosen when you need reach to clear obstructions around the drain pad. It is not the bolt centre or the port size.

What is bolt centre?

Bolt centre is the distance from the centre of one bolt hole to the centre of the other on your turbo's oil drain pad. It identifies the frame class: 38mm (1.50") small frame, 50mm (1.97") mid frame, 50.8mm (2.00") large frame.

Does this flange work with journal-bearing and ball-bearing turbos?

Yes. It fits journal-bearing and ball-bearing turbos alike when the turbo has a small-frame 38mm (1.50") drain pad bolt centre.

What fitting outlet does this turbo drain flange use?

It uses a full-sized 10AN male port to support high-flow oil return and help keep the drain line running freely.

Why choose this billet flange over an OEM cast drain flange?

The billet construction provides a flatter, more consistent sealing surface than many stock cast flanges, helping reduce distortion and leaks while supporting longer service life.

Is this turbo drain flange made in Canada?

Yes. It is made in Canada by BSI Inc. and ships from Canada.