Valve Timing is Everything

916-886XD

Variable valve timing (VVT) was a breakthrough technology when it first arrived. By continuously fine-tuning the timing of the intake or exhaust cams (or both), it became possible to achieve optimum performance while reducing fuel consumption and harmful emissions. To achieve these conflicting objectives, VVT systems use electric solenoids that vary the amount of oil flowing to hydraulic cam adjusters, also called phasers.

Dorman pioneered VVT components for the aftermarket in 2011 when the technology was becoming more common, but today variable valve timing is found on everything from basic economy cars to high-end SUVs. With more VVT-equipped vehicles on the road than ever before, Dorman not only engineers direct-replacement valve timing components but also improvements on original equipment designs that have proven exceptionally prone to failure.

For instance, the original equipment VVT solenoid on some General Motors vehicles fails prematurely, typically between 80,000 and 100,000 miles. Dorman’s engineers examined countless samples of these failed units that all suffered a loss of oil pressure as a result of leaking internally.

By deconstructing these samples, the engineers discovered a weak stationary center tube that was wearing out, allowing excessive internal movement that eventually led to their failure. Engineering analysis resulted in a new design that incorporates a stronger brass tube. Thorough design analysis and testing confirmed the new part was up to the task before pre-production samples were ordered for vehicle testing.

The resulting OE FIX VVT solenoids (916-886XD and 918-005) are a stronger, longer-lasting design that eliminates the problem with the original. The engineers also increased the oil flow through the part with additional oil passages. As a bonus, Dorman added the hard-to-source gasket andincluded it in the installation hardware kit to ensure a reliable repair.

In the case of the cam phasers used on numerous V8-powered Ford, Lincoln and Mercury vehicles, the manufacturer acknowledged a failure rate of nearly 1 in 3 with the original design. Dorman’s ideation team recognized this high warranty claim rate as an opportunity to design abetter product.

The engineering team’s internal research revealed interference between the rotor and vane inside the phaser. Friction between these parts was the source of untimely wear on the locking plate that resulted in a loss of oil pressure and performance.

Dorman’s engineers went to work on this problem and came up with a redesign that started with a stronger alloy locking plate. They also reconsidered the rotor design entirely and came up with an improvement that earned Dorman a patent (U.S. Patent # 9341089 B2).

The original equipment manufacturer also recognized the problem with the initial design for this cam phaser. In fact, they went back to the drawing board for seven revisions. While the OE was busy redesigning its parts – and aftermarket competitors were simply replicating one version or another of the OE design – Dorman’s patented OE FIX cam phaser (917-250XD) became the industry standard aftermarket replacement for this popular application.

Dorman’s expertise after so many years of producing VVT components has been applied to ever-evolving variations on the basic concept on other related engine management technologies. Multi-displacement systems, for instance, deactivate cylinders to increase fuel efficiency when demand for power is low, such as in highway driving. These systems are actuated by solenoids that are very similar to many VVT solenoid designs. Dorman has already produced an OE FIX multi-displacement solenoid (916-511XD) that upgrades the plastic solenoid body to aluminum for better heat resistance.

VVT technology has helped make the internal combustion engine more powerful and efficient than ever before. Dorman will ensure these systems remain reliable well into the future, producing affordable replacement components to keep them on the road and continuing to engineer improvements whenever possible.

Engine Variable Valve Timing (VVT) Solenoid

916-886XD
General Motors 2017-06, Isuzu 2016-08

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Problem:

The original VVT solenoids on certain vehicles fail in extreme conditions.

Our replacement features multiple improvements, including a patented upgraded copper core to eliminate internal movement and extended service life.