GM ZZ4 Crate Engine - Repurposing

Breathe new life into an old short-block with a few aftermarket parts

Camp 1207 01 Z Gm Zz4 Crate Engine Refresh 1/18

1. Our starting point is this clean ZZ4 GM Performance Parts 350-inch short-block. At some point someone swiped all the parts off of it and left it languishing in a corner. Back when it was all together, this GM crate engine was rated at 355 hp and 405 lb-ft of torque. Not bad, but we’re pretty sure we can improve on those numbers without sacrificing street manners or breaking the bank.

These days, recycling is all the rage. Airplanes get ground up and turned into beer cans, which eventually get melted down and formed into some other widget we just can’t live without. In a way, hot rodding is one of the “greenest” hobbies out there. We take old, worn-out junk and rebuild it into functioning items. This is especially true of engines. Sometimes it’s an old crank that’s cleaned up and put to use again, or maybe it’s a discarded engine block left to gather dust in the back of a shop. Whatever it is, the whole concept of turning trash into treasure is what drives our hobby.

Camp 1207 02 Z Gm Zz4 Crate Engine Refresh 2/18

The nexus for this story was an old short-block we found in the back of the shop. After doing a little sleuthing, we determined it was the remnants of a GM ZZ4 crate engine. We’re pretty sure that a lot of hot rodders have half-built engines lying about, so why not see what a few aftermarket parts could recycle these mills into.

In this case, the ZZ4 first hit the streets well over 10 years ago. Back then, 355 horsepower seemed like a much bigger number, and the price of gas actually was a much smaller one. So our plan is to up the power a bit by using a less expensive grade of gasoline. We also wanted to try out a few parts that have recently caught our attention. The first was a Thumpr cam from COMP. These hydraulic roller cams are ground and profiled to maximize the rough-idling characteristics without negatively impacting the power output or streetability of the engine. In other words, the hot rod sound we love without the hassle.

We also wanted to try out Summit’s new line of affordable aluminum heads. The cost of cylinder heads can quickly consume the lion’s share of any engine building budget, so finding some affordable choices that still make good power really helps in keeping the cost down. To make sure we did it right, we hauled all the parts over to JR Competition Engines in Escondido, California.

MORE PHOTOS

VIEW FULL GALLERY

COMMENTS

TO TOP