LS Engines / Tech Articles

LS Tech: How to Delete Variable Valve Timing (VVT) on an LS Engine

GM LS Valvetrain

(Image/GM EFI Magazine)

Variable Valve Timing (VVT) is a system that automatically adjusts valve timing.

GM used VVT on the following engines within the LS family.

LS VVT Applications

DisplacementRPO Code

(Summit Racing’s Paul Spurlock and Brian Nutter contributed to this article.)

How Does VVT Work?

The computer senses engine load. It also monitors valve timing through the camshaft position sensor. It then uses that VVT data to determine the best valve timing for the current conditions.

The computer sends a signal to a solenoid on the timing cover. The solenoid controls oil flow through a special control valve in the camshaft bolt. The valve sends oil into the phaser control chambers.

The actuator rotates one way or the other, depending on the oil flow. That rotation is used to advance or retard the camshaft as needed.

How Does VVT Affect Performance?

VVT gives you the best of both worlds. It can advance valve timing for a smooth idle and low-end torque. It can also retard the valve timing for more top-end power. And, it’s all done automatically.

VVT becomes an issue when swapping a cam:

  • Piston-to-valve clearance can be a problem.
  • Your choices for valve lift and duration are limited.
  • The high spring pressure required for performance cams can overpower the actuator.

If you want to upgrade your camshaft and keep the VVT system, you will need a Camshaft Phaser Limiter.

If you want high performance from a bigger cam, you will need to delete the VVT system. (More on that in a second.)

How You Can Tell Whether Your LS has VVT

Engines with VVT will have a camshaft phaser actuator on the timing cover. They also have a five-pin connector for the VVT and camshaft sensor.

Engines without VVT will not have the actuator. They only have a three-pin connector for the camshaft sensor.

LS Gen 4 Timing Covers VVT

These are two LS engine timing covers. The one on the left has the camshaft phasing actuator, indicating that it is from an engine with VVT. The one one the right has no actuator, so it is from an engine without VVT. (Image/Summit Racing)

GM used two different actuator designs.

In 2007-08, the actuator has 62-degree rotation. GM part number 12585994.

In 2008-15, the actuator has 52-degree rotation. GM part number 12606358.

How Can I Delete the VVT on my LS Engine?

Eliminating the VVT system is required when swapping to a non-VVT camshaft. These cams offer higher valve lift and longer duration for more performance.

A VVT delete kit removes the VVT components and replaces them with standard parts. At a minimum, they include:

  • A Gen. 4, non-VVT timing cover
  • A new, 4X, non-VVT upper timing gear
  • A new harmonic balancer bolt
  • New camshaft bolts

Some kits will also include additional parts, such as:

  • A new lower timing gear
  • A new timing chain
  • A new timing chain guide

The type of VVT Delete Kit you need depends on the camshaft you are using.

1-Bolt Camshafts

3-Bolt Camshafts

Eliminating the VVT system is required when swapping to a non-VVT camshaft. These cams offer higher valve lift and longer duration for more performance.

After installing one of these kits:

  • You will be locked-in to the valve timing.
    • The computer will no longer automatically adjust the valve timing.
  • You will also need to tune the computer.
    • This will optimize the fuel and ignition curves for the new camshaft, and turn off the VVT system in the computer.
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  3. Norm FRENCHY LaFountaine says:

    Is there a link to INSTRUCTIONS on removing the VVT components and replacing with the VVT Delete kit?

    • OnAllCylinders Staff says:

      Hey Norm, replacing the VVT components is much like doing a cam swap. Really the upper cam sprocket is the main difference. You can find directions to performing a LS cam swap HERE.

  4. If i put a motor with vvt system into a truck model without the vvt system
    Can I just not plugging it or i need vvt cancel kit ?
    I apologize for my writing , I’m not really good in English.
    Thanks .

    • Etienne, your English is just fine.
      If you used the ECM and harness from the VVT equipped engine, it will work. If you tried to use a non-vvt ECM, the engine will not perform well because the cam would always be in the “parked” position.
      The phaser moves as much as 62 degrees, so you can imagine a camshaft being in the wrong position the majority of the time. It would be much better to install a VVT delete kit and a non VVT cam before you put the engine in the vehicle.

      • Can i put a 2013 4.8 into my 2005 Express (4.8 with 250k miles) with the VVT delete kit and keep the installed cam? (not a performance application)

  5. If you use a VVT delete kit can you use say edge and diablo tuner that turns the VVT off? or do you need to send the ecm off to have it tuned out?

    • OnAllCylinders says:

      If a disabler is used, it will not need to be turned off inside the ECM. If you’re looking for added performance though, a tune is well worth the money.

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