2019 Big Stock 1100 Lb. Class
1. Piston must not come out of the bore.
2. Governor must be in working order.
3. 68 cubic inch MAXIMUM.
4. 45 cubic inches and under are allowed to run 5000 rpm at 1100 lb. 45.1-68 cubic inches are allowed 5000 rpm at 1100Lbs. (Zero tolerance)
5. Single or twin cylinder, four cycle, 2 cylinder diesel or gas, air or liquid cooled, flathead or OHV. No Turbo.
6. No locked rear-ends.
7. Gasoline, diesel, or E85 only. NO NITRO, NO NITROUS, NO POLYPROLINE OXIDE, NO DIOXANE, NO ADDITIVES, at the discretion of the tech committee. If club officials determine fuel being used smells as though it is not pump fuel or as though it has additives, the owner will receive a warning on the first offense. If a second offense occurs, the tractor will not be allowed to pull for the remainder of the year.
8. No stock engine overbore will be allowed over .040” from the original bore.
9. Stock means stock motor, stock frame, at the discretion of the tech committee.
10. No tires over 26x12x12 in size. No duals.
11. No welded heads.
12. All engines must have stock stroke, stock spec valves, stock appearing carb, stock casting heads, and stock intake manifold.
13. Naturally aspirated.
14. No standoff pipes.
15. Wheelbase should not exceed 56”
16. Must have throttle stop on engine in working order.
17. Porting is allowed.
18. Steel flywheels mandatory.
19. Milled heads are allowed as long as you don’t alter the ramp or the valve pocket. Only one head gasket in stock location is allowed.
20. All starter pulleys must be 1” wide by 8” diameter aluminum billet, not steel. Also, no front counter weight allowed.
NOTE: During a protest or teardown, head or heads must be removed.