Stop chasing leaks from undersized or poorly machined drain flanges. This 100mm billet 12AN turbo drain flange is precision-machined to fit right and seal right the first time.

Features & Benefits

• Exact bolt centre fit — machined for mid-frame turbos at 50mm (1.97") and large-frame turbos at 50.8mm (2.00"), so you're not forcing a universal flange to do a specific job.
• 100mm (3.94") drain length — the longest of the three lengths we offer. The drain body stands well off the flange face, giving you the reach to get your hose connection out past a manifold, frame rail, block accessory, or a tight turbo mount. Also available in 35mm (1.38") and 65mm (2.56").
• 12AN male port — connects directly to braided or hard-line -12AN oil return setups for a clean, leak-free oil drain back to the sump.
• Billet construction — machined from solid billet stock for superior strength and a precision sealing face that cast alternatives simply can't match.
• Clean sealing surface — the precision-machined face minimizes the risk of oil weeps and seepage at the turbo drain, keeping your build tidy under the hood.
• Designed and made in Canada — manufactured by BSI Inc. and shipped to builders across North America, with CAD pricing and no cross-border guesswork on your order.

Whether you're laying down a street build or pushing the limits on a competition setup, this is the drain flange that pulls its weight without compromise.

Not sure which drain you need? See the S400 Turbo Oil Drain Guide for bolt centre measurement, length selection, and full sizing charts in metric and US standard.

FAQ

What turbochargers is this drain flange designed for?

This flange is engineered for mid-frame and large-frame turbochargers — a 50mm (1.97") bolt centre on mid frame and 50.8mm (2.00") on large frame.

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. Measure with calipers, as mid and large frame sit only about 1/32" apart.

What oil return setup does the port fit?

The 12AN male port connects directly to braided or hard-line -12AN oil return setups.

Why choose billet construction?

It is machined from solid billet stock for superior strength and a precision sealing face compared with cast alternatives.

Where is this turbo drain flange made?

It is designed and made in Canada by BSI Inc. and shipped to builders across North America.