Section 22 - LIGHT LIMITED MODIFIED TRACTORS (LLM)

Unless specifically outlined below in the class specific rules, the Tractor General Rules and the overall General rules outlined above will apply.

22.1 - General Rules

1. Light Limited Modified Tractors will compete at a maximum weight of 6,000 lbs.

   1. No tolerance unless noted otherwise.

1. Allowable fuels, alcohol, diesel, kerosene, any form of gas/race gas, absolutely no nitro methane or nitrous oxide allowed.

2. EFI is allowed on any engine combination listed within the Engine Combinations section.

22.2 - Tires

1. Tire size allowed is 30.5 x 32 maximum. See General Tractor Rules for dimensions.

2. Tire size shall not exceed 31 inches in width.

22.3 - Engine Combinations

1. Maximum of one 650 cubic inch billet automotive style engine hemi heads allowed with maximum blower size of 14-71 no overdrive limit, no screw blowers allowed.

2. One methanol fuel injected Allison v12 aircraft engine limited to 8.8 supercharger ratio with stock wheel and 8.1 with billet wheel overdrive ratio.

   1. A methanol injected Allison with stock pistons limited to a 9.6 to 1 supercharger ratio.

3. One carbureted gas Allison v12 aircraft engine limited to 9.6-1 supercharger overdrive ratio.

4. One carbureted gas Merlin or Packard style v12.

5. Two (2) automotive type engines with a maximum 2.300” intake valve, a maximum 8-71 supercharger limited to 11% overdrive, no Hemi, Pontiac, Oldsmobile, Big Chief or Big Duke style heads, 650 cubic inch limit.

6. Any combination of N/A wedge head automotive style engines with a combined displacement of 1500 cubic inch.

   1. Under 750 CID will be allowed to run at 7000 lbs.

7. Any combination of forced induction wedge head automotive style engine with combined displacement of 750 ci, no billet blocks or heads allowed.

   1. Turbos limited to one per bank, non-staged.

      1. Aluminum heads - 76mm inducer compressor side, 76mm exducer turbine side.

   2. Types of engine driven blowers allowed are centrifugal and roots. No overdrive limit, no variable speed device, No screw blowers.

   3. No intercoolers allowed.

   4. Under 375 ci will be allowed to run at 7000 lbs.

8. One Ag or Industrial style engine limited to:

   1. Diesel fuel engine using a 4.1 turbocharger with a maximum of 640 CID.

   2. Alcohol fuel engines with a maximum of 505 CID.

   3. Aftermarket aluminum heads allowed, no overhead cams or hemi style combustion chambers.

   4. Ag or industrial diesel limited to 4.1” smooth bore with maximum 4.5” exhaust wheel. Intake wheel must protrude no more or less than 1/8-inch into housing; exhaust wheel must protrude 1/8” into housing, no map width enhancement (MWE) allowed, exhaust must exit through max 4.5” bore in housing.

9. One small block AG engine on alcohol with:

   1. 4.1 in smooth bore inducer compressor side and 4.5 inch turbo exducer turbine side. Intake and Exhaust wheel must protrude 1/8in into housing. No Map Groove. Exhaust must exit through 4.5in housing.

   2. Not to exceed 460 CID.

   3. Overhead cam cylinder head is allowed.

10. Allowed turbine engine combinations:

    1. One Lycoming T53 L-13 turbine with water injection at 6200 lbs.

    2. One Lycoming T53 L-13 turbine and a naturally aspirated wedge head style automotive engine with a maximum of 370 CID at 6000 lbs.

    3. Twin Lycoming T53 L-11 with water and alcohol injection.

    4. Single T53 L-1 or L-11 will be allowed to run at 7000 lbs

    5. One Lycoming T55-L5 Rated at 2200hp military spec. Must be sealed at authorized repair shop. Water and/or alcohol injection is allowed.

    6. All turbine engines must be operated within military specifications.

11. Any combination of automotive-style diesel engines i.e. Duramax, Cummins, Powerstroke.

    1. Limited to 900 ci displacement,

    2. May run one turbo per engine limited to 76mm inducer compressor side and 88mm exducer turbine side. Intake and exhaust wheel must protrude 1/8” into housing

    3. No intercoolers are allowed.

    4. Water injection is allowed.

    5. Under 450 CID will be allowed to run at 7000 lbs.

12. Allow 88X103mm turbos for 750ci Automotive engine and Ford GAA engine on alcohol limited to two non-staged turbo chargers, one per bank. 88mm inducer compressor 99mm exducer turbine side. Intake and exhaust wheel must protrude 1/8” into housing.

13. Allow 88X103mm turbos o 750ci Automotive engine and Ford GAA. Cast aluminum or iron wedge head. No billet. Conventional only. No Big Chief heads. No Hemi Heads.

    1. 2 non-staged 88mm turbo inducer compressor side and 99mm turbo exducer side.

    2. 1 non-staged 4.1in smooth bore inducer compressor side and 4.5in turbo exducer side. Intake and exhaust wheel must protrude 1/8 in. into housing. No Map groove. Exhaust must exit through 4.5 in housing.

14. All turbine engine exhaust stacks must have a minimum of 3 restraints distributed equally around the stack. The restraints must be attached to the stack and to a solid mounting point such as the steel hot section shield or tractor frame rails. Restraints must contain the exhaust stack to the vehicle if the stack was to come loose from the engine.