Here's the rules:
Pro Stock Compact Diesel Tractor Division:
1)Maximum weight 2100 lbs.
2)Single engine with a maximum of 250 cubic inches
3)This class is for stock appearing tractors with full hood, grill and side panels. Must be recognizable as an actual modern production compact tractor or small farm tractor. Hood and grill can be from a different make that engine/frame/rear end.
4)Engine must be compression ignition and use #2 Diesel Fuel* only. No spark plugs or alcohol as a fuel.
5)Hitch height up to 15 inches allowed
6)Engine must be commercially produced with at least 1000 units built. Engine block must have factory casting model and serial numbers visible. O.E.M. block cannot be altered in any way externally except for normal repair or for mounting fuel injection pumps.
7)Maximum of 4 cylinders
8)May be liquid or air cooled.
9)No belt driven cooling fans. Electric fans only.
10)O.E.M. head for that make/model engine only. No billet or aftermarket heads. No overhead cams. Maximum of 2 valves per cylinder. Injectors must remain in stock location.
11)No billet injector pumps. No electronic or common rail injection systems.
12)Tractors are allowed a single (1) turbo charger with any manifold modifications necessary to mount the turbocharger. Manifold pressure may be a single stage only.
13)Turbocharger must be single shaft fixed vane type. No variable vane turbochargers allowed. No inlet or outlet size restrictions.
14)Turbo must be fitted with a shutdown guillotine on the compressor inlet side of the turbo.
15)Turbochargers not under the hood will be completely shrouded with steel .060” or thicker, except for inlet and exhaust pipes. Turbochargers under fiberglass hoods must be shrouded, except for the inlet and outlet pipes, with .060” steel or thicker under the area of the fiberglass.
16)No wastegates or pressure reliefs of any kind permitted. All compressed air to enter the intake manifold.
17)All turbocharged engines are required to have one cable that must surround the engine block and head. This cable shall be located between the first and second cylinder through the exhaust manifold port area. The cable will be a minimum of 5/16” thick with two (2) clamps at the splice. The cable should allow for approximately 4” of slack.
18)Water injection will be allowed. Must be plain water or water with water soluble lube only. Combustible agents (alcohol, oxygenators, etc.) are NOT allowed in water injection.
19)No intercoolers or after coolers
20)No propane, nitrous injection or any type of secondary fuel system of any kind will be permitted.
21)Any stock appearing frame rail or tube frame is permitted. Tube frame must be covered with sheet metal.
22)Full metal side panels to cover engine area. Minimum .060” steel or aluminum
23)All inline engines are required to have an additional inner side shield consisting of .125” (1/8”) thick steel or titanium OR .250” (1/4”) aluminum inside of the current .060” steel or aluminum side panels with a minimum of .500” (1/2”) air gap. This shield is to be independent of the side panels and must be solidly attached at the top and bottom (4 point total minimum) with a minimum of 5/16” fasteners. This shield must extend from the bottom of the head to the centerline of the crankshaft and extend the full length of the block on each side of the engine.
24)All tractors must have a fuel shut-off AND an air shut off mounted in the drivers’ compartment and within reach of the driver. Fuel shut off must return fuel to tank or loop back to pump.
25)Kill switch device mounted on rear of tractor must disconnect power to the electric fuel pump along with activating turbocharger guillotine.