SpeedFactory 5.5mm Viton Valve Stem Seals for Honda/Acura

SpeedFactory 5.5mm Viton Valve Stem Seals - Honda/Acura B/D/F/H/K Series and F20C/F22C

Blue smoke on cold starts or under hard acceleration means one thing - your valve stem seals are shot. Oil's dripping past the guides into the combustion chamber, and stock rubber seals are the culprit. SpeedFactory makes these replacements from DuPont Viton, a fluoroelastomer that stays flexible and seals properly where OEM rubber hardens and cracks. If you're doing a head rebuild or chasing an oil consumption issue, swap these in and don't think about it again.

What Happens When Valve Stem Seals Wear Out

Valve stem seals sit at the top of each valve guide. Their job is to meter oil along the valve stem - enough to lubricate the guide, not so much that it dumps into the cylinder. Factory seals are nitrile or EPDM rubber. After years of heat cycling and oil exposure, they harden and crack. Once they crack, oil seeps down the guide on every intake stroke. That oil burns off as blue smoke - most visible on cold starts before the engine warms up, and again on hard deceleration when vacuum spikes. Sound familiar? Your seals are done.

Why Viton Holds Up Where Rubber Fails

Viton (also called FKM) is rated for 400°F+ continuous service. Your cylinder head doesn't get close to that under normal conditions - but in a forced induction build, after a long track session, or running E85 where combustion temps climb, the heat differential matters. More importantly, Viton doesn't react to aggressive fuel chemistry. E85, race gas, high-detergent synthetic oils - Viton handles all of it without swelling or degrading. OEM rubber seals weren't engineered with those fuels in mind. These were.

These Are for 5.5mm Valve Stems

These fit 5.5mm valve stems - not the stock Honda 5.0mm intake stems you'll find on a lot of factory builds. This matters. If you're running aftermarket valves from Supertech, Ferrea, or Del West, those are almost universally 5.5mm for both intake and exhaust, which is exactly what these are sized for. If you're staying completely stock on a D-series or a non-VTEC B-series, verify your stem diameter first. Measure before you order - getting the wrong size means the seal either falls off or doesn't seat, and neither is acceptable on a freshly rebuilt head.

Sold as a Set of 8 - One Head

One set of 8 covers one cylinder head - either all intakes or all exhausts, not both. Every DOHC Honda (B16, B18C, K20, K24, H22, F20C) runs 8 intake and 8 exhaust valves per head, so a complete head job means two sets: one intake, one exhaust. Don't cheap out and do half the head. If one set is worn through, the other set has the same heat cycles on it. You're already in there - do it right the first time.

What You Get

• SpeedFactory 5.5mm Viton valve stem seals (8-piece set, intake or exhaust)
• DuPont Viton (FKM fluoroelastomer) construction
• 400°F+ continuous temperature rating
• Compatible with E85, race fuel, and full-synthetic oils
• Machined metal jacket with polished sealing surfaces
• Internal garter spring for consistent radial tension

Compatible Engines

• B-series VTEC (B16A, B17A, B18C)
• D-series (D15, D16 - verify 5.5mm stem diameter)
• F-series VTEC (F20B, F22B VTEC)
• H-series VTEC (H22A, H23A VTEC)
• K-series (K20A, K20Z, K24A, K24Z)
• F20C, F22C (S2000)

Fits These Cars

• 1989-2001 Acura Integra
• 2002-2006 Acura RSX
• 2004-2008 Acura TSX
• 1988-2000 Honda Civic
• 2002-2011 Honda Civic Si
• 1988-1991 Honda CRX
• 1993-1997 Honda Del Sol
• 1990-2007 Honda Accord
• 1997-2006 Honda CR-V
• 1992-2001 Honda Prelude
• 2000-2009 Honda S2000

Important: These are sized for 5.5mm valve stems. Measure your valve stems before ordering - factory Honda diameters vary by engine and application. You'll need two sets for a complete DOHC head (one intake, one exhaust). Installing valve stem seals requires a valve spring compressor and attention to installed height specs. If you're not set up to do that correctly, hand the head to a machine shop - it's a short job for them and a lot cheaper than a bent valve or a crushed seal.