While other stages can be selected independently (i.e., you can go right to Stage 5 and add both the cam and heads without completing stages 2-4), that is not the case with Stage 1. All other stages require that this stage be completed before the others are performed.
Stage 1 is a mandatory stage for the build of our ZZ4. The various stages to be outlined here build greater horsepower by adding a specific combination of performance parts. For the purpose of comparison, we will use these figures to determine the power gains from our component changes. The 355hp rating and 405 lb-ft of torque are great street performance figures, but was that the real performance generated? Equipped with a Demon 650-cfm double-pumper carb (to free us of the vacuum secondaries) and 1 3/4-inch Super Comp headers, we pulled a few levers on the SuperFlow dyno, and read the charts.Īfter a number of adjustments for jetting and timing, our best numbers were 344 hp and 390 lb-ft of torque, a difference of 11 hp and 15 lb-ft of torque from the advertised numbers (which were spec'd with the larger 770-cfm crate motor carb). To test our theory about the responsive nature of the ZZ4 as a performance platform, we began by taking baseline dyno numbers on the engine. A range of component tests was performed in an attempt to create the five-stage program shown here.
But for the performance fan looking to really turn up the heat, there are a few things that can quickly garner almost 100 extra horsepower without a great deal of effort.Īll of the tests were performed at COMP Cams' R&D center using a SuperFlow dyno. Delivered with an aluminum dual-plane intake manifold, HEI distributor, 770-cfm vacuum-secondary carb, cast-iron water pump, damper, and flex plate, you just need to add fuel and air, then twist the key. Perhaps the best part of the ZZ4 is not simply its reasonably priced performance (a turnkey ZZ4 crate typically costs under $4,900), but its response to classic engine upgrades. To anyone looking for simple turnkey performance and a great building block for further power modifications, the ZZ4 has become the small-block Chevy of choice.
The classic small-block ZZ4 is a quality built 350ci engine rated at 355 hp and 405 lb-ft of torque. Walk down any row of the local car show and you will probably see a vehicle powered by General Motors' now venerable ZZ4 crate engine. The ZZ4 short-block from GM Performance Parts is the perfect platform for generating reliable street power.
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