Camshaft
A camshaft (more commonly referred to as a cam) is a core component in the engine. It controls and actuates the opening and closing of the valves.
Contents
Function
In the Z32, the camshafts rotate with the crankshaft (though at half the speed). The VG30DE(TT) features a DOHC or Dual Over[H]ead Cam design. In fact, that's what the "D" in "VG30DE" stands for. Because the VG30DE is a V-configuration engine, there are two separate heads--one for each cylinder bank. This gives the VG30DE a total of four camshafts. However, because each head has two cams, it is still referred to as a DOHC setup.
Camshafts have eccentric lobes, shaped like eggs. As the camshaft rotates, the lobes press against the lifters, which press against the valves, to open them and allow air to enter (intake side) or exhaust gas to escape (exhaust side). Aftermarket cams are available which feature different opening and closing points for the valves in addition to different lift heights. These can drastically alter the behavior and performance of the engine.
Different Versions
The Z32's engine has a confusing collection of different cams, depending on the year, aspiration, and transmission.
Intake Cams
All intake cams except TT Auto had the same cam profiles. The only differences between PI and PII in respect to the cams are the mounting points for the cam gears.
Like-colors are the same, they were just given to their models (NA or TT) at different times.
| |
Non-Turbo |
TT Manual |
TT Auto |
| Phase I |
90-92 |
90-93 |
90-93 |
| Phase II |
93-95 |
94-95 |
94-95 |
| OBDII |
96 | ||
Additional Notes
- Phase II (new style) cams, while functionally the same as their Phase I counterparts, have slightly different mounting points for the cam gears, which featured evolutionary changes following the same phases.
- Driver's-side and passenger's-side cams are identical and interchangeable with their respective models (see table above).
- When standing in front of the engine, the two "inner" camshafts are for the intake. The "outer" camshafts are for the exhaust.
Specifications
- TT Automatic: 240deg intake, 8.5mm lift. 248deg exhaust, 8.5mm lift.
- All other models: 248 deg, 8.5mm lift (intake & exhaust).
Exhaust Cams
- 90-95 (all models)
- 96 (all models)
Note: All exhaust cams feature the same front face and mounting points for the gears, which are also the same. The 96 exhaust cam had a different lobe profile to help the engine meet 96+ emissions standards.
