ZZ6: How GM Celebrated An Anniversary with a New Crate Engine

ZZ6 crate engine

GM makes some of the best crate engines ever made. They come ready to rule the road and track. In 2015, GM celebrated the 60th anniversary of the Chevy small block with a ZZ6 crate engine (part number 19351533). Here’s a look at the GM crate engine and what we know about the ZZ6.

When the Crate Engine Was Born

The world wasn’t formerly introduced to the crate engine until (sort of) recent years. Rewind 35 years and you could buy an engine in a crate from your local GM dealer. However, this wasn't quite the same part we can get now. These engines were limited new runs, stockpiled performance engines, and so on.

About half way through the 80s, the small block started to evolve. Production plants were now capable of making a more complex engine. This was the beginning of the end of the two-piece rear main seal with forged crank engine.

This came after a decade of disappointment when it came to OE engine power. Hydraulic roller engines were made for better gas mileage and lower emissions, but they offered more. It was really the power rating of these new engines that caught the attention of the American driver. These engines with aluminum heads and high performance gains started in the Corvette first.

The large production volume of these performance engines brought the price down. As a result, hot rodders could finally afford a high tech engine for their builds and swaps. This brought about a new era in the attitude toward GM engines.

GM set up production of engines compatible with the current offerings. This new engine would become known as the H.O. 350. Stamped on the passenger side cylinder head of these engines was the code ZZZ. The ZZZ release was the marker of the start of modern crate engines.

First debuted in 1989, they had a four bolt main block, forged one-piece rear main seal crank, L98 heads, and 9.8:1 compression ration. GM’s ZZ 350 engine family would go on to win grudge races and settle bets. It's not the most powerful platform ever made, but for the size and simplicity, it can’t be beat.

GM Gifts the World With ZZ6

After many years of making ZZ engines, GM has a pretty good idea what they’re doing. The ZZ1-ZZ5 represent several years of the engine's evolution. For 2016, GM announced the newest ZZ replacement, the ZZ6. It includes a larger than ever 770-cfm Holley carb, 1.5:1 roller rocker arms, and single plane intake. This new engine is officially rated at 405 horsepower @ 5,600 RPM, and 405 lbs-ft of torque at 4,600 RPM.

ZZ6 Engine Specifications:

Horspower: 405 @ 5,600 rpm

Torque: 405 @ 4,600 rpm

Block Type: Cast iron Chevy 350 small block with 4-bolt main

Bore x Stroke: 4.00” x 3.48”

Crank: Forge

Cam: Hydraulic roller

Cam Duration @ .050”: 208 intake/221 exhaust

Valve Lift: .474 intake/.510 exhaust

Rocker Arms: Roller 1.5:1

Connecting Rods: Forged

Pistons: Hypereutectic aluminum

Intake: Aluminum

Cylinder Heads: 62cc

Compression: 9.72:1

Fuel: 93 octane

Timing: 36 degrees @ 4,000 rpm

Peak Horsepower RPM: 5,600

Part Number: 19351533

Just as the prior engines have been, the ZZ6 is ideal for high performance street cars. Also like the previous ZZ engines, it’s setup to respond well to common bolt-ons. This new ZZ engine gives hot rodders an awesome new swap engine. It also represents the original crate engine perfectly.