The manufacturing of valve springs is more than achieving the required pressure and lift.  There are many other factors to consider when it comes to achieving a superior spring design and when done correctly it makes a big difference in the reliability and successful operation of the springs.

Dual Valve Springs Specifications, Part number Spr-H1021D:

Outer Spring: 30.00mm O.D., 21.80mm I.D.

Inner Spring: 21.30mm O.D., 15.50mm I.D.

Pressure: 95lbs. @ 40.40mm Seat, 253lbs. @ 12mm Open (lift)

Max Net Lift: 17.70mm

Coil Bind: 22.70mm

Rate: 13.20mm

Supertech Black Nitride Valves 

The micro hardness is higher than the stainless steel base material.  Good ductility beneath the hard nitrided layer (micro hardness is 8000HV minimum).  Surface finish is smoother than chromed stems.  Less friction between stem and guide.  Harder valve seat surface, lasting longer with lead free fuels, alcohols, nitro or other "explosive" mixes.  Matches any kind of seats (nodular iron, steel powder metal, hard aluminum-copper or be ryllium copper).  Less valve guide friction = reduced power loss.  Nitride layer is adhered to the base material at a microscope level, so it will not "flake" or brake.  Nitride is applied to the whole valve while the chrome coating is only applied to the stem.  All valves are swirl polished, have stem undercuts, a hardened tip and more. 

Black Nitride Valves Specifications, Part number HIVN-1030D & HEVN-1030D:

Intake Valve: Head Diam 36.00mm, Stem Diam 5.48mm, Length 109.85mm (Standard Size - Dished)

Exhaust Valve: Head Diam 31.00mm, Stem Diam 5.45mm, Length 108.80mm (Standard Size - Dished)

Note: Flat Face Valves are also available at buyers request.

What's in the box?

(16) Supertech Dual Valve Springs

(16) Supertech Titanium Retainers

(16) Supertech Valve Spring Seats

(16) Supertech Black Nitride, Standard Size, Dished Intake & Exhaust Valves

(16) Supertech Manganese Bronze Intake & Exhaust Valve Guides

(16) Supertech Intake & Exhaust Valve Stem Seals

Note: All items are of OEM standard size unless otherwise noted.  We can customize any Supertech Performance Valvetrain package for you.  We usually return a response the same day. 

Made to fit:

1999 - 2003 Honda S2000 AP1 F20C

2004 - 2009 Honda S2000 AP2 F22C

Shipping

1) We ship within 24 hours of complete processed payment with the exception of weekends and holidays.  Delivery is usually 2-4 business within the United States.
2) Free shipping is provided to the lower 48 states.
3) Customers located in Alaska, Hawaii and Puerto Rico should contact us for best possible shipping rates.