Wiseco B Series Forged Piston Kit for 90-01 Integra

Wiseco B Series Forged Pistons - B16/B18 Motors

You're building a B series motor and you need pistons that aren't going to crack when you're making serious power. Wiseco forges these pistons from 2618 aluminum for B16 and B18 motors. They're designed for all-motor builds, turbo builds, and everything in between. The 2618 alloy's way stronger than the cast or hypereutectic pistons Honda uses from the factory. These pistons handle detonation, high cylinder pressures, and sustained high RPM without cracking. Wiseco makes these pistons in four different bore sizes: 81mm (stock B18), 81.25mm (+0.25mm over), 81.5mm (+0.5mm over), and 82mm (+1mm over). You can get them configured for naturally aspirated builds or turbo builds. The pistons run between 8.2:1 and 8.6:1 compression ratio depending on your exact application. If you're swapping a VTEC head onto a non-VTEC block, these pistons work for that too.

Here's Why 2618 Aluminum Matters

Stock B series pistons are cast aluminum. Cast pistons work fine for stock power levels but they're brittle. When you start making serious power, whether that's from high compression and aggressive cams or from boost, cylinder pressures go up and cast pistons crack. The top ring land cracks, the skirt cracks, you're pulling the motor apart to replace broken pistons. Wiseco forges these pistons from 2618 aluminum. The forging process compresses the grain structure and makes the material way stronger. The 2618 alloy itself has higher tensile strength and better heat resistance than the cheaper 4032 alloy you see in budget forged pistons. That means these pistons handle detonation events without cracking. If you accidentally lean out and you get a little knock, the 2618 pistons absorb it. Cast pistons would crack.

ArmorGlide Skirt Coating

Wiseco coats the piston skirts with ArmorGlide. That's a friction-reducing coating that lets the piston move up and down the cylinder bore with less resistance. Less friction means less heat, quieter operation, and better seizure resistance if you ever lose oil pressure or your cooling system fails. The coating also helps the pistons survive initial startup when there's not full oil pressure yet. Stock pistons don't have a skirt coating so they're scuffing the cylinder walls every time you cold start the motor. ArmorGlide prevents that.

Anti-Detonation Grooves and Forced Pin Oiling

Wiseco machines anti-detonation grooves into the top of the piston. Those grooves disrupt the flame front during combustion and reduce the chance of detonation. They're not going to save you if you're running a garbage tune but they help. The pistons also have forced pin oiling. There's an oiling hole that directs oil to the wrist pin during the compression stroke. That keeps the pin and the small end of the rod lubricated under high loads. Better lubrication means less wear and longer life.

Pick Your Bore Size and Application

Wiseco makes these pistons in four bore sizes. Stock B18 bore is 81mm. If your block's still at stock bore and the cylinder walls are in good shape, you can run the 81mm pistons. If you're rebuilding a high-mileage motor or you've got some scoring in the cylinders, you might need to overbore. The 81.25mm pistons are a +0.25mm overbore. The 81.5mm pistons are a +0.5mm overbore. The 82mm pistons are a +1mm overbore. Your machine shop will measure your cylinder walls and tell you what bore size you need. Don't guess. Have them measure it with a bore gauge.

When you're ordering, you'll also need to specify whether you're building a naturally aspirated motor or a turbo motor. The piston configuration's different between the two. If you're building an all-motor B series with cams and a built head, order the naturally aspirated pistons. If you're building a turbo motor, order the turbo pistons. The compression ratio's going to be between 8.2:1 and 8.6:1 depending on your exact motor combination, head type, and deck height. That's a safe compression range for both all-motor and turbo builds. For all-motor, 8.5:1 to 8.6:1 gives you good power without needing race gas. For turbo, 8.2:1 to 8.4:1 lets you run boost on pump gas without knocking.

VTEC Head on Non-VTEC Block

These pistons work for B18A and B18B non-VTEC motors and they also work for B18C1 and B18C5 VTEC motors. If you're doing a mini-me build where you're putting a VTEC head on a non-VTEC block, these pistons work for that too. The piston dome design's compatible with both VTEC and non-VTEC combustion chambers. You're not hunting for special pistons. The same Wiseco B series pistons work across the whole B18 family. They also work for B16A2 and B16A3 motors if you're building a B16.

What You Get

• Wiseco forged piston set for B series motors (4 pistons)
• Forged from 2618 aluminum in the USA
• ArmorGlide skirt coating for reduced friction and seizure resistance
• Anti-detonation grooves machined into piston crown
• Forced pin oiling for wrist pin lubrication
• Precision-machined ring grooves
• Fully machined crown for structural integrity
• Available in four bore sizes: 81mm, 81.25mm, 81.5mm, 82mm
• Available for naturally aspirated or turbo applications
• Compression ratio: 8.2:1 to 8.6:1 (depending on application)
• Piston rings included
• Wrist pins and circlips included
• Compression height: 30.00mm
• Wrist pin diameter: 0.827 inch (21mm)

Fits These Motors

• B18A1
• B18B1
• B18C1
• B18C5
• B16A2
• B16A3
• VTEC head on non-VTEC block builds

Note: Have your machine shop measure cylinder walls with a bore gauge before ordering - don't guess on bore size. Order naturally aspirated pistons for all-motor builds or turbo pistons for boosted builds - the piston configuration's different between the two. Follow Wiseco's piston-to-wall clearance specs for 2618 aluminum during assembly. Too tight and the pistons will seize when hot, too loose and you'll have piston slap and blow-by.