A Cam Gear is a gear that mounts to the front of a camshaft. The crankshaft rotates the timing belt, which is connected to the cam gear, rotating the camshaft.

BDE_Performance_VTC_Gears.jpg
A set of BDE Performance Gears, which are modified stock intake gears.


Different Versions

There are a few different types of cam gears used on the VG30DE/TT.

Intake Gears

Related Article: Variable Timing Control.
There are four different types of Intake Cam Gears that have been found on the Z32. It's not necessarily correct to call them all VTC gears, as not all versions implemented variable timing control.

Thanks to Brett Dempsey for this information and pictures.

Variants

  • Early, 90-93NA, 90-94TT – identified by the six round holes surrounding the inner hub.
  • Hybrid, 90-93NA, 90-94TT – *service replacement* – identified by the bolt-on outer cog AND the 1.280” (32.5mm) camshaft pocket depth. These were sold by Nissan as replacements for early-style gears, but they are visually very similar to the late-style gears.
  • Late, 94-95NA, 95TT – “Service Replacement” identified by the bolt-on outer cog AND the 1.015” (25.8mm) camshaft pocket depth.
  • 1996 USDM-only Non-VTC - The 1996 USDM models deleted the VTC function due to OBDII compliance issues. These pulleys look similar to Late VTCs with their bolt-on outer cog but with the exception of a smaller diameter center hub. This hub is solid and cannot be converted to VTC functionality.
Year
Non-Turbo
Twin Turbo
1990
Early
Early
1991
Early
Early
1992
Early
Early
1993
Early
Early
1994
Late
Either
1995
Late
Late
1996
Non-VTC
Non-VTC
Note, Nissan began transitioning these components in 93 and 94. Some vehicles from 94 have been found with late-style gears, while most use old-style.


VG30DE intake pulley ID med.jpg
VTC 90-93NA, 90-94TT SERVICE REPLACEMENT ID med.jpg


The camshafts themselves also changed with the cam gears.


Early vs Late Style

Phase I and II intake cam gears perform the same function but feature slightly different designs. Both feature variable timing control, but Phase II cam gears also received adjustable cam phasing, like many aftermarket cam gears. However, the intention wasn't to create tuner-gasms, it was to make the manufacturing process easier--after the gears were assembled, the adjustable cam phasing could be used to center the VTC assembly at 0° more easily.
It should be noted, for those wishing to take advantage of the stock adjustable cam gears, that they do not have a defined "center" point. Brand new cam gears have been found to be "adjusted" right in the center, or all the way to the side. Further, the adjustment bolt heads are on the rear of the gear and therefore cannot be adjusted without removal.
BDE Engineering sells modified intake cam gears designed to eliminate VTC rattle, and where applicable, modifies the stock adjustable cam gear to give a centered range of adjustment as well as adjustibility from the front.

Adapters

JWT sells adapter spacers allowing you to install Phase II gears on Phase I cams. This is useful as many aftermarket cam gears match the Phase II gears' dimensions and fitment.

Exhaust Gears

All exhaust cam gears are identical, non-adjustable type. Easy, right?

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