SpeedFactory Titanium Manifold Stud M8x1.25x65mm (Single)

Running an intake manifold spacer, a thick thermal gasket stack, or a custom flange on your B or D series and the 55mm studs still only catch a few threads? This is the longest of SpeedFactory's singles: one M8x1.25x65mm titanium manifold stud with a titanium 12-point nut and washer, sold individually. It's the measure-first option for setups where standard-length hardware runs out of thread.

What It Is and Why It Works

SpeedFactory machines these from Ti 6Al-4V, the same Grade 5 titanium used in aerospace fasteners. It's stronger than the factory steel hardware and immune to the rust that seizes and snaps original Honda manifold studs. The stud carries a 3mm hex key tip, so it threads into the head with an Allen key rather than the double-nut trick. The complete stud, nut, and washer assembly weighs about 14 g, per manufacturer.

The M8x1.25 thread pitch matches the intake and exhaust manifold hardware on Honda and Acura B series (B16, B18, B20), D15 and D16, F20B, the S2000's F20C and F22C, and the Prelude's H22 and H23, plus the intake side of a K series head. K series exhaust manifolds use M10x1.25, so this is not the part for a K swap header.

Length is the buying decision. The 45mm stud covers stock manifolds and headers, the 55mm handles most aftermarket intake manifolds and thermal gaskets, and this 65mm version exists for the thickest stacks: a phenolic spacer plus gasket, doubled-up thermal gaskets, or custom flanges. As a rule of thumb, you want roughly 8mm or more of thread showing past the nut face without the stud bottoming in the runner. Measure your combined flange and gasket thickness before ordering.

Specs

Available Options

Fitment

Thread pitch is what matters on hardware like this, not the chassis. Any Honda or Acura manifold location running an M8x1.25 stud takes this part, including B16 Civics, B18A and B18B Integras, and swapped EG, EK, and DC2 builds on B, D, F, or H series power. Confirm your original hardware is M8x1.25 and measure your stack before ordering.

What to Know Before You Buy

Be honest with yourself about whether you need 65mm. On a stock manifold this much stud sticks way out past the nut, looks unfinished, crowds tight runner bends, and can make getting a socket on the 12-point nut a knuckle-buster. Most aftermarket intake manifold setups are happy at 55mm. Buy the 65 because you measured and the stack demands it, not as insurance.

Install is the same as the shorter lengths. Hand-thread into a clean bore, snug with the 3mm Allen key, and don't lean on the hex tip, it's for installation, not torque. Clamp load comes from the nut, torqued to your factory manifold spec. Titanium in an aluminum head can gall, so run nickel-based anti-seize on the threads and retorque after a few heat cycles, especially on exhaust or turbo duty. If you're refreshing a whole manifold instead of replacing one stud, the SpeedFactory 10-piece titanium stud kit we carry does the full B, D, F, or H series flange in one order.