What is VVL? What is VVT? How does VVL/VVT work? What is variable valve lift? What is variable valve timing? We're going to ...

Since the beginning of hot rodding, gearheads have endeavored to increase the performance of internal combustion engines through the optimization of valve timing. It's been proven time after time that ...

Harley-Davidson has filed a patent application for a variable valve timing (VVT) V-twin engine, possibly for the Sportster to improve economy and reduce emissions. The iconic American manufacturer has ...