New ZZ6 Chevy Small-Block Advances Crate Engine Legacy

Oct 7, 2015

Developed with contemporary technologies including a high-rpm valvetrain, Chevrolet Performance’s new ZZ6 crate engine offers builders a modern twist on the classic Chevy small-block 350.

It uses updated Fast Burn cylinder heads with beehive-style valve springs inspired by the LS engine family-a feature that enhances high-rpm capability, enabling the new high-performance engine to achieve 405 horsepower and 405 foot-pounds of torque, according to Chevy.

That’s more power than any factory-produced 350 engine ever installed in a Chevrolet production vehicle, making it one of the most powerful 350 small-block-based crate engines in the nearly 27-year history of the “ZZ” lineup.

“The new ZZ6 is the ultimate ZZ 350-based crate engine from Chevrolet Performance,” said Jim Campbell, GM U.S. vice president of performance vehicles and motorsports. “After more than six decades, our powertrain engineers continue to refine and update the classic small-block architecture, adapting new technologies to advance the legacy of the industry’s most adaptable V-8 engine and giving customers new choices from the company that pioneered the concept of high-performance crate engines.”

A pair of high-flow, Fast Burn-style aluminum cylinder heads, with large intake runners and 2.00/1.55-inch valves, enable the ZZ6 to flow big air, while the beehive-style valve springs offer high-rpm performance and durability, Campbell noted. A unique, tapered shape of the valve spring allows for the use of a smaller spring retainer, which reduces the reciprocating mass of the valvetrain, resulting in better valve dynamics.

The ZZ6 also uses an aggressive hydraulic roller camshaft, with 0.474/0.510-inch lift and 208/221-degrees duration, that supports the engine’s high-rpm airflow capability, while maintaining excellent low-speed drivability.

Rounding out the rotating assembly is a forged steel crankshaft and durable, quiet high-silicon aluminum pistons housed in a four-bolt-main cast iron block.

A pair of all-new, aluminum valve covers caps off the new crate engine, giving it a distinctive, premium appearance. Chevrolet Performance offers the ZZ6 crate engine in Turn Key and Base versions.