The engine in Chuck Karnatzs...
The engine in Chuck Karnatzs 36 Ford is the popular GM Performance Parts ZZ4. Its a typical small-block displacing 350 cubes and running 9.5:1 compression with aluminum heads and a decent street performance cam. Chucks is a little different because hes running Holley Pro-Jection electronic fuel injection, but since the Pro-Jection throttle body is designed to replace a four-barrel carb, a four-barrel nitrous system can be used.
After removing the air cleaner...
After removing the air cleaner and disconnecting the fuel inlet and return lines, the fuel inlet barb fitting is removed from the throttle body in preparation for the adapter fitting from the nitrous kit.
Once the throttle linkage...
Once the throttle linkage and the electrical connections have been disconnected, the four retaining nuts are removed and the throttle body is pulled from the intake manifold.
This close-up shows the adapter...
This close-up shows the adapter fitting installed between the throttle body and the inlet barb fitting. This will divert fuel to the nitrous fuel solenoid, to be mounted later.
The NOS Powershot system is...
The NOS Powershot system is an entry-level kit designed to provide 125hp boost, and is nonadjustable. For Chucks car, So-Cal selected the Super Powershot kit, which is adjustable, allowing for 90-150hp boost, depending on which jets are used. Kits come complete with the injector plate and the fuel and nitrous solenoids (shown), plus all the necessary fittings and lines to plumb the system, the electrical hardware, and a 10-pound nitrous bottle.
The injector plate slips over...
The injector plate slips over the carb (or in this case, throttle-body) studs. Its only 1/2-inch thick, but some applications may still require longer studs. A standard carb gasket is used between the plate and the manifold, and another will be used between the plate and the throttle body.
The throttle body is reinstalled...
The throttle body is reinstalled on top of the injector plate, and then the linkage and electrical connections are reconnected.
The solenoids are carefully...
The solenoids are carefully clamped in a vice, using a rag to prevent damage, and then the fittings are installed, using Teflon paste on the threads to ensure a positive seal. The paste is preferred over thread tape, because the tape can sometimes become lodged in the ends of the fittings, thus obstructing flow. Since this kit is designed to provide a specific balance between fuel and nitrous oxide, the proper delivery of each is critical.
This is one of the solenoids...
This is one of the solenoids shown with the injector-plate line installed. The jet is also shown just ahead of the open fitting to illustrate where it fits in the system. The jet actually slips into the fitting on the injector plate, and then the fitting from the line installs over it. Fittings are colorcoded to distinguish between nitrous and fuel; blue for nitrous, red for fuel.
J After the jet is inserted...
J After the jet is inserted in the fitting on the injector plate, the line from the solenoid is attached. Note that Teflon paste is not required for these connections, which use AN-style fittings. These connections are intended to be removed and installed numerous times to allow jet changes.
K The fuel line connecting...
K The fuel line connecting the adapter fitting installed on the throttle body with the fuel solenoid is shown here. Aircraft-style braided line is used for added safety, and So-Cal pressurizes the fuel system prior to operation to check for leaks. The solenoid mount is also illustrated here, fastened to the throttle-body base-plate stud.
This micro-switch, also included...
This micro-switch, also included in the kit, will activate the nitrous system.
It must be mounted so that...
It must be mounted so that it is tripped only when the throttle is fully depressed. A cockpit-mounted toggle switch is used to arm the system. Operation is simple: Open the valve on the nitrous bottle, flip the toggle to arm the system, and the next time the throttle reaches the floor, youll get an extra 90-150 hp, depending on the jetting selected.
Despite the various concerns over suspension, upholstery, paint, and so on, that we occupy ourselves with when it comes time to build or update a modern street rod, the whole idea for hot rods in the first place was to go faster. Though this concept is sometimes lost in the mix, it does seem to be making a comeback with street rodders, particularly now that drag racing is reemerging at some events.
Of course, the focus for the majority of us isnt going to change from functional driver to all-out racer, but it might be nice to gain a slight advantage over the other guy, should you find yourself in the staging lanes sometime in the coming season. So rather than rushing out to get a new engine, why not take a page from the guys who race every weekend: Install a nitrous oxide system.
The basic concept is simple: The more fuel your engine can burn, the more power it can make. The challenge has always been to get more air into the engine so that it can burn more fuel. Nitrous oxide, or N20, is made up of nitrogen and oxygen. When injected into the engine, the heat of combustion separates the nitrogen atoms from the oxygen atoms. This additional oxygen can then be matched with additional fuel (also injected by the NOS system) to maintain the optimum air/fuel ratio and generate more power.
Although these systems have been around for almost 30 years, nitrous still seems to be a novelty on street rods, but its got to be the easiest way to add 100-plus horsepower to your engine. Chuck Karnatz knew that when he commissioned the staff at the So-Cal Speed Shop to install a system from NOS on his 36 Ford coupe in preparation for our Asphalt Ego-Rama last summer. The system definitely helped Chucks e.t.s during the drag portion of our competition and didnt hinder the cars driveability in the least when it wasnt in use. The accompanying photos and captions outline the installation procedure.