The National Hot Rod Association (NHRA) has sanctioned drag races across America every year for more than 50 years. Fans and drivers of all shapes and sizes can come and enjoy a day at the track. Young competitors can begin racing in the NHRA's Jr. Dragster League at eight years old. When racing is what your kid loves to do, build him a Jr. Dragster according to the rules of the NHRA and get him racing competitively in an upcoming NHRA Jr. drag-racing sponsored event.
Things You'll Need
- Rolling chassis Wood blocks Wheel & tires 5hp Briggs & Stratton engine Mounting brackets (angled) Tachometer Hand tools Clutch Chain
To build a junior dragster, begin with a rolling chassis. It should come with a finished driver's compartment and all pedal linkage, brakes and steering intact. Raise the chassis off the ground at least 24 inches. Support the frame using wood blocks or a frame lift. Make sure the frame is level and that the supporting blocks are spaced far enough apart to continue supporting the weight securely as more weight is added to each end of the chassis. Secure the front wheels including tires on the front axle. Align the wheel onto the axle using existing wheel studs or a hub-centric axle that centers the wheel on a pin prior to securing the wheel to the axle.
Secure the engine mounts to the tube frame. Tighten the mounting bracket to the frame rail using the frame bolts that come with the bracket. Seat the engine onto the bracket and use the bolt fasteners to connect the engine to the mounting bracket. Be sure that the drive shaft side is facing the rear axle wheel, which will be connected by the chain. Mounting the engine in reverse is possible, so pay attention to the way you seat the engine onto the mounting bracket before tightening the bolts all the way.
Attach the clutch and clutch wheel to the engine so that they are aligned with the drive wheel of the axle. Connect the chain around both engine and drive shaft sprocket and tighten the chain by adjusting the space in between the engine and the axle drive wheel. Finish securing the engine to the mounting bracket when the chain has been tightened correctly. Use a torque wrench to tighten the bolts with even pressure.
Connect the accelerator linkage to the engine and test the pedal for correct distance of travel for the accelerator cable. Secure the cable in place with the engine cable clamp and recheck the travel of the cable end to be sure the pedal activates the throttle correctly. Wire the ignition to the driver's compartment and connect the battery prior to testing.
Put on the large, rear slick tires after completing the engine installation. The lug nuts on each wheel should be evenly tightened. Do not completely tighten one lug then another. Work around the wheel and tighten with a torque wrench to spec. Raise the completed car from the wood blocks and remove the supports. Lower the car to the floor and begin testing the parts after assembly.
Tips & Warnings
- Choose chassis and engine packages that are recommended by the sanctioning body. Adjust the spark plug gap to achieve a smoother idle and better take off speed. Use Royal Purple oil as the lubricant in these one-cylinder race engines.
- NHRA Rules: If you do not follow them, then do not expect to be able to compete. Building a Jr. Dragster for kids who drag race means you will be working on it most every weekend.
- Photo Credit Powerfitz, S. Walsh
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