Skunk2 is proud to introduce its Alpha Valve Spring and Titanium Retainer Kits for Honda’s B-series VTEC, D-series VTEC, H-series VTEC, and K-series iVTEC engines. Each kit includes Skunk2’s high-quality dual valve springs (single for D-series) and race-proven titanium retainers that are the result of nearly two decades of racing and engine building experience.

Each Alpha Valve Spring is manufactured exclusively from super-clean, chrome-silicone wire milled in Japan. By using inner and outer springs mated together through a slight interference fit and with differing frequencies, Alpha Valve Springs are able to prevent valve float and maintain valvetrain stability at engine speeds in excess of 10,000 rpm.

Skunk2’s industry-leading Alpha Titanium Retainers are designed to significantly reduce valvetrain mass, resulting in more horsepower and improved valvetrain stability. Similar to Skunk2’s already popular Pro Series Titanium Retainers, Alpha Titanium Retainers feature radius-cut edges for additional rocker arm clearance and reduced weight, strategically positioned lightening grooves, and reduced overall heights for better valve seal clearance and even further weight reduction.

Alpha Titanium Retainers are manufactured using the latest 3D CAD (Computer Aided Design) and FEA (Finite Element Analysis) to ensure that each is optimized for strength as well as for reduced weight. Skunk2 engineers then test and prove their designs on the engine dyno as well as the race track. Once approved for manufacturing, only medical-grade titanium that’s been ultrasonically inspected and certified is used. Following CNC machining, each retainer is then individually inspected to ensure proper hole diameter, taper, and that each are free from machining defects to ensure proper installed valve spring heights and pressures. Finally, each retainer is serialized for your protection, including valuable information, like material batch specifics as well as production and inspection dates.

Skunk2 designs, develops, and tests its entire valvetrain lineup in-house to ensure superior quality and maximum performance gains. During development, each valvetrain component is tested both on the dyno and the road, including 11,000 rpm drag racing engines and 17,000 rpm superbikes. Manufactured from the best materials available, Skunk2 valvetrain components provide exceptional performance, reliability, and quality and remain standard-issue on each Skunk2 vehicle that we build and support

Engine Applications:

• D-series* VTEC - D16Z6 (Si/EX), D15B (JDM), D16Y5 (HX), D16Y8 (EX)
  *single springs
  Seat pressure: 165lbs @ 1.500" / Pressure: 585
• B-series VTEC - B16A/B, B17A, B18C/C1/C5
  Seat Pressure: 68lbs @ 1.320”
• H-series VTEC - H22A1/A4 & JDM H22/H23 VTEC
  Seat Pressure:Seat Pressure: 50lbs @ 1.400” -- Open Pressure: 205lbs @ 0.900” / Coil bind: 0.880"
• K-series* - K20A/A2/A3/Z1/Z3, K24A2
  Seat Pressure: 60lbs @ 1.600”

*K-series Alpha Spring Info:

Seat Pressure: 60 lbs at 1.600”
Open Pressure: 220 lbs at 1.100”
Coil Bind: 1.000”

K-series engines that are originally equipped with single valve springs must use a K-series dual valve spring base kit (available separately) and cotters (keepers) from pre-2004 K20A2 engines.

When using Skunk2 Titanium Retainers on 2004 and newer K engines, pre-2004 keepers (cotters) must be used (Honda P/N 14781-PR7-A01). Pre-2004 keepers can be identified by the absence of marks along the top edge (2004 and newer keepers feature laser-etched marks along the top edge). For applications where 2004 and newer keepers are used, Skunk2 Titanium Retainers must be used. Proper retainer/keeper selection is important due to varying angle ratios between earlier and later keeper designs. Use of improper retainers and/or keepers may result in potential engine damage.