65mm Billet 10AN Turbo Drain Oil Flange

Stop fighting ill-fitting drain flanges. This precision billet 10AN turbo drain flange is machined to match the bolt centre of mid-frame turbochargers right out of the box.

Why Builders Choose This Flange

Precision bolt centre

Machined to the 50mm (1.97") bolt centre used by mid-frame turbos, including the S300. Bolt centre is the distance from the centre of one drain pad bolt hole to the centre of the other. Measure yours with calipers before ordering, because mid frame and large frame sit only about 1/32" apart.

65mm (2.56") drain length

The 65mm 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 middle of three lengths, with enough standoff to clear most obstructions without adding bulk. Also available in 35mm (1.38") and 100mm (3.94").

Direct 10AN male port

The integrated 10AN port connects straight to your oil drain line, with no extra fittings, no additional leak points, and no wasted time sourcing adapters. A 10AN return suits the majority of street and towing mid-frame builds.

Billet construction

Cut from billet for superior strength with a precision-machined sealing surface at the drain port face, and a captured high-temperature o-ring rather than a paper gasket or RTV.

Built for mid-frame applications

Suited to mid-frame turbocharger builds including street performance rigs, track cars, and boosted diesel haulers, in journal-bearing or ball-bearing form.

Canadian-made by BSI Inc.

Manufactured in Canada and stocked for fast shipping across Canada and the United States.

Build it right, seal it right, and keep your oil where it belongs — in the engine.

Running a large-frame turbo such as an S400? That is a 50.8mm (2.00") bolt centre and a 12AN port is the better choice — see the S400 Turbo Oil Drain Guide for bolt centre measurement, length selection, and port sizing in metric and US standard.

FAQ

What turbochargers is this 65mm billet 10AN turbo drain flange made for?

It is machined for mid-frame turbochargers, which use a 50mm (1.97") bolt centre. The S300 is a mid-frame turbo.

What does the 65mm refer to?

65mm (2.56") is the length of the drain, meaning how far the drain body stands off the flange face. It is a clearance and routing choice, 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.

Should I run a 10AN or 12AN drain?

A 10AN return is adequate for most street and towing mid-frame builds. Step up to 12AN on high-boost, sustained-load, competition or compound applications, or if you have had drain-related trouble before.

Is this flange suitable for journal-bearing and ball-bearing turbos?

Yes. It can be used whether you are running a journal-bearing or ball-bearing unit.

Does installation require modifying the turbo centre housing?

No. The direct bolt-on design fits without modification to your turbo's centre housing.