You can’t build an engine properly without the necessary tools, right? Especially when it comes to something as critical as checking the piston to valve clearance on a brand-new engine. “Guessing at it” isn’t exactly a precision measurement technique, and that’s where Mike Scano and MS Racing Components comes into the picture with their VVT Unlocker system.

With the popularity of the Gen IV and Gen V GM LS/LT engine exploding over the last several years, Scano realized that there was no way to properly measure the piston-to-valve clearance during the camshaft degreeing process.

The factory design of LS/LT engines has the camshaft’s variable valve timing phaser locked at 7 degrees advanced when there is no oil pressure, which doesn’t permit the piston-to-valve clearance to be measured when the camshaft is in the full retarded position. This is not a problem with the factory camshaft where clearances are not an issue, but when an aftermarket camshaft with larger lift and duration figures is installed, it becomes critical.

The process is simple – remove the factory camshaft center valve, install the VVT Unlocker, hook up some shop air to the VVT Unlocker, release the phaser, and check your measurements.

When you’re all done, release the air pressure, swap out the VVT Unlocker for the factory center valve and torque it down, and have a clear understanding of where the piston-to-valve clearances are in your new setup.

Verification of the piston-to-valve clearance throughout the cycle is now possible, and it takes only a minute to perform. There are three current versions of the VVT Unlocker: PN MSVVT-1 for 2007-13 Gen IV LS engines, and MSVVT-2 for 2014-up LT1/L83/L86 Gen V engines. There is also a late-model Hemi version available (PN MSVVT-3) and a Ford 4.6/5.4-liter Modular version is in development. Scano says there is a patent pending on the tool to cover all engine platforms with VVT designs.

Simple, right? Sometimes the most useful tools are just that – simple. Neat stuff!