Hilliard Winter Championship

Open Class‚Äč  13" hitch - 1150#

1. Open class is defined as any tractor having  one cylinder, air cooled,

    four cycle flat head engine with no cubic inch limit or any TWO 

    one cylinder, air cooled, four cycle flat head engines not exceeding

    50.5 cubic inch displacement per engine.
2. Clutch shields with a maximum center diameter hole of 6 inches.
3. Tires are limited to a 15 inch diameter rim size.
4. All exposed turbochargers or portions thereof must be shrouded

    with 1/16 inch steel, or thicker.
5. All super charged engines must have a shield on the belt.
6. Plenum tubes must be attached in a manner that will not let them 

    fall off of a tractor.
7. Nitro (OUTDOOR PULLS ONLY) and/or Nitrous permitted on

    unblown engines only.

 *All Hilliard general and safety rules will be strictly enforced*