Valve Spring Dimensions And Valve Spring Pressure Load

WARNING: This page is about a different car, the 2005 Nissan 350Z. However, it is still accessible from the selected car via links, so may be relevant.

Check valve spring pressure at specified spring height.
- Standard:
  - Intake and exhaust
    - Free height
      - : 47.07 mm (1.8531 in)
    - Installation height
      - : 37.00 mm (1.4567 in)
    - Installation load
      - : 166 - 188 N (16.9 - 19.2 kg, 37 - 42 lb)
    - Height during valve open
      - : 27.2 mm (1.0709 in)
    - Load with valve open
      - : 373 - 421 N (38.0 - 42.9 kg, 84 - 95 lb)
Fig 1: Checking Valve Spring Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.
If the installation load or load with valve open is out of the standard, replace valve spring.