Vermont Tractor Pullers Association
Pro Stock Diesel 1100 lbs & 1200 lbs 2015-2018 Driver Eligibility: 1. General Rules apply. 2. Drivers must be at least 16 years old and capable of operating the tractor in a safe manner. 3. Helmet, fire suit having a minimum single layer rating of SFI 3.2A-1, and closed toe shoes REQUIRED. Hood sock and gloves are recommended. 4. A tractor may be entered only once per class. 5. A pro stock diesel tractor competing in the pro stock diesel class cannot move up a class in the same event. Chassis: 6. Maximum wheelbase is 56 inches. 7. Maximum distance from center of rear axle to farthest point forward is 96 inches. 8. Tractor must have a stock appearing hood and grill (nose piece).  Switching to another factory sheet metal is permissible. 9. Must use a garden tractor rear end/transaxle.  No cut down automotive rear ends or Panzers. 10. Must have a “dead man” throttle.  Throttle shaft must have return spring in case of a breakage in linkage. 11. ALL TRACTORS MUST HAVE a functional breakaway kill switch.  Kill switch device must be mounted on rear of tractor and must disconnect power to electric fuel pump along with activating turbo air shut off. (Refer to diagram in back of book) 12. All tractors must have fenders to protect driver from the rear tires.  Fenders should extend at a minimum of 4 inches out over the tires.  All tractors must have at least a 3 inch seat back. 13. Wheelie bars must be rigid in all directions and able to support the tractor and driver in the heaviest class.  Each skid shoe must be a minimum of 1.5”x 2” or the use of 5” round wheels 1” wide is allowed.  Tractor must have 2 skid shoes or 2 wheels.  The wheelie bars must be a minimum of 5” from the rear most part of the tire and maximum of 10”.  The bars must be a maximum of 5” from ground to bottom of skid shoes or wheels.  A vertical bumper bar 6” in height in rear most position is required.  Weights on back of tractor must be contained up to 1” before end of the wheelie bars. (Refer to diagram in back of book) 14. Maximum hitch height is 13”.  Must provide own clevis or straight flat plate with 1 ½” hole with a dead man zone of 3” on each side of the hitch.  Hitch must be rigid in all directions.  The kill switch must be centered approximately 10”-12” above the hitch in this area.  (Refer to diagram in back of book) 15. ALL TRACTORS MUST HAVE a minimum of a 1 lb fully charged fire extinguisher on board, in reach of operator.  A functional gauge on the fire extinguisher is REQUIRED. Engine: 16. Engine will be no more than 3 cylinders.  May be liquid or air cooled. 17. Engine will be no more than 75 cubic inches. 18. Water injection will be allowed. 19. Engine modifications are permitted: Rods, Pistons, Cam and Fuel System. 20. Engine must have block casting model and serial numbers visible. 21. Engine must have OEM intake manifolds and exhaust manifolds, polishing is permitted. 22. Head work is permitted on stock heads.  No billet heads.  No overhead cams. 23. Injector and injector pump modifications allowed.  No billet injector pumps. 24. Turbo charging is permitted, but limited to one turbo only. a. Turbo will be fitted with an air shut off on the compressor inlet side of the turbo. b. Exhaust “L” of turbo must have minimum of ¼ inch cross in elbow with exhaust to discharge vertically. 25. Electric fuel pump supply is permitted with positive power wire to have a disconnect at rear of tractor. 26. No propane or nitrous of any kind will be permitted. 27. Engine Shielding Rules: Minimum thickness of 16 gauge steel on external side of cylinder extending from head gasket to frame.  Shield must be attached to frame at the bottom and the block at both upper corners. 28. Must run ¼ inch cable around oil pan over top of valve cover in a complete circle connected with cable clamps. 29. No Fin or Cast Flywheels. 30. Clutch assembly and flywheel must be surrounded 360 degrees with 1/8 inch steel or 3/16 inch aluminum. Tires and Wheels: 31. Maximum tire size: 26 x 12.00 x 12 alterations allowed. *Note:  If there ar not at least 3 Pro-Diesel tractors to make a class at an event, these tractors may pull with the Limited Pro-Diesel class with a disadvantage of hitch and weight to be determined at that time.