Читать книгу How to Install and Tune Nitrous Oxide Systems - Bob McClurg - Страница 15

The premise of a single-stage 4-barrel N₂O carburetor-plate kit, whether it’s designed for the street or for competition use, didn’t take a brain surgeon to figure out. The nitrous oxide plate itself looks like a standard 1/2- to 1-inch-thick 4-barrel carburetor spacer plate. In fact, I wouldn’t be surprised if that’s what its inventor originally adapted it from. Then along came the addition of fuel and N₂O jet ports accompanied by brass, aluminum, or stainless-steel spray bars. They feature a series of finely drilled holes running either north/south, or east/ west, depending on carburetor type and throttle linkage design. When you activate the N₂O system, this combination of gasoline and N₂O gets mixed with the atomized fuel from the carburetor, and is distributed throughout the intake runners to the combustion chambers. Once lit, the byproduct is an instant and dramatic burst of power!

Over the past 40 years, the crossbar-design N2O plate has been accepted as the standard of the industry.

Not all single-stage carburetor plates are alike. In an ongoing attempt to improve on the basic 40-year-old design and perhaps gain a larger market share, some manufacturers (like Nitrous Express and ZEX Nitrous Products) have introduced advanced design nitrous plates, such as the ZEX Perimeter Plate, as standard equipment.

You may be asking, “Why a fuel port when there’s already a carburetor?” The most obvious reason is the power adder concept itself, keeping in mind that N₂O enters the intake runners of an internal combustion engine at 127 degrees F.

N2O and fuel jets are both CNC manufactured from either brass or stainless-steel and are drilled, or inner-contoured, per each N2O manufacturers’ specifications in order to arrive at what is perceived to be the ideal rate of flow. Jet size ranges from .014 to .136 inch on average. Per application, a series of pre-selected jets are typically included in a single-carbureted street N2O kit. For example, with Edelbrock Corporation’s 50- to 100-hp Universal Big-Block Chevrolet Square Flange (nitrous) Kit (PN 70001), the grouping of three N2O and fuel jets are perfectly matched to their counterparts.

The molecular density of N₂O is such that you need an additional shot of fuel—using a properly matched gasoline jet—to offset the nitrous charge and fire the cylinder. Otherwise, you have to run a huge carburetor jet, which affects overall fuel mileage and driveability under normal driving conditions.