General Rules and Regulations:
1. Modified Mini Tractors are defined as any tractor without standard block or crankcase for make and model of chassis in which engine is mounted
2. No portion of any tractor may exceeds' forward of the center of the rear wheel
3. No portion of any tractor shall exceed 6' in width
4. Aftermarket Transmissions are ALLOWED
5. Weight Classes to be 1650LB and 1800LB
6. V-8 Mini Modified rear ends are to be as mass produced by OEM manufacturers. (I.E. Ford, GM, Dodge) As Found in passenger cars or light duty trucks. Must be able to accept OEM center sections. May be aluminum of OEM or to OEM Specs and Likenesses. No Aftermarket will be allowed of planetary versions or planetary type.
1. All tractors shall have wide front axles. Front wheels shall track within the rear wheels
1. V-8 Mini Modified Tractors will be naturally aspirated. Maximum Cubic Inches to be 410ci. Single engine only, with only two (2) valves per cylinder and one (1) spark plug per cylinder. No Big Blocks or Hemis Allowed. Aluminum blocks allowed.
2. A deflection shield is required on both sides of all engines. Shield must extend the complete length of block casting and be securely fastened. It is to be made of aluminum or steel a minimum of .060" thick or safety blanked material. Shields must be solid motor mounts, filters steering rods ECT., Cannot Serve as part of shield, providing it covers required areas of block casting. it is recommended that a quick release be used.
3. Starter motors, fuel filters, oil filters and fuel injection pumps may not be used as shielding. Shielding MAY cover of pass behind starter or fuel pump.
4. Shielding must extend from base of head or the uppermost point of piston, travel to 2" below bottom center of crankshaft throw, and be securely fastened
5. Side Shields must be mounted independently of the engine block, motor mount, block saver plate and header mounting or chassis mounting is acceptable.
6. All blow-by tubes must exit forward of the rear tires. Engine crank venting: All engine crank case venting blow-by tube must be vented below the head of the engine and extend down to the engine pan.
7. All vehicles must be equipped with a deadman throttle, all throttles working in a forward-rearward direction, throttles shall be closed in the rearmost position. No hydraulic throttles allowed. All throttles must have duel return springs to the closed position. All foot throttles to have a toe strap
8. Harmonic balancers; All Automotive engines equipped with a harmonic balancer: Balancer shall be solid steel or SF1 Certified
9. A bolt in the crankshaft to hold damper pully is required.
10. All engine fans must be shrouded with steel 1/16" or thicker, 360* Degree
1. All exhaust must discharge vertically. Height to be a minimum of one foot above the bend in the pipe which discharges vertically measured from top of pipe to bottom of bend. All exhaust pipes must be securely attached, Vertical PS defined as being within 10* degrees, in any direction of being plumb. Rain caps may not be used, no megaphone pipes allowed.
Fuel and Fuel Containers:
1. All forms of Nitromethane (including Nitrous Oxide) are illegal as fuel or fuel additive for pulling. Legal fuels are alcohol, water, diesel fuel, aviation gas, gasoline, propane gas, no oxygen carriers or combustion accelerators.
2. No Pressurized Fuels allowed except in UL. Approved pressure tanks, no oxygen allowed.
1. All Kill Switches must be mounted independently of the draw bar and or wheelie bars.
2. All Pulling vehicles must have an automatic ignition kill switch, in working order at all times. track officials have the option of checking kill switches as many times as they feel adequate at any event. Switches must be checked with engine running.
3. Kill Switch must be in rear center (maximum of 6" off center in any direction), 18" above the point of hook
4. On a Spark Plug ignition engine, the kill switch must break or ground the ignition circuit. On Vehicles equipped with spark ignition circuit. On Vehicles equipped with spark ignition engines and electric fuel pumps the kill switch must also break circuit to the fuel pump.
5. The breakaway kill switches must have attached to them a minimum of 2" diameter ring. The Cable from the sled will be attached to this ring.
6. Portion of the kill switch and mounting brackets must be able to stand 32lbs of pull per switch when pulled independently or collectively
7. Kill Switch must be secured with a nylon tie wrap 1/8". This wrap must be broken for are-pull
8. If vehicle has kill switch or shutoff located in legal position and during the pull it is pulled and nylon strap broken, and the presiding judge inspects and finds switch capable of operating properly under normal conditions, vehicle will be allowed to Re-Pull immediately or drop 6 positions. decision to drop must be made before vehicle leaves the track. it is the puller's responsibility to see that the switch is checked by the official before leaving the track.
9. All ignition engines must have bar type master shut off switch for all motors in working order within easy reach of driver.
1. If presiding official and tech official feel a vehicle is unsafe, they have the right not to allow the vehicle to pull.
2. All pulling vehicles, must be equipped with a minimum of 2LB Halon type fire extinguisher, fully charged, in working condition and convenient to operator.
3. All drivers must wear helmets. Helmets must have chin strap fastened while pulling. Helmets must meet or exceed Snell 85 rating or must be SF1 Spec .312. No modifications or alterations allowed.
4. All trucks and tractors using alcohol fuel it is mandatory to wear a fire suit, consisting of a minimum of one (1) layer Nomex 3 or equivalent of SF1 Certification
5. Competing card holder must be seated in or on the vehicle when his/her engine or engines are being started and running & have complete controls of the vehicle at all times. Only when the vehicle is hooked to the sled can the driver leave the seat with the engine running.
6. A reverse safety light system is required on all tractors. A white light automotive quality minimum 2" in diameter, must be mounted directly above or below the safety kill switch at the rear of the tractor. A light in the driver’s compartment must be operated off the same system, both lights are to be activated by a shift lever such that will only be lit when the vehicle is in reverse.
7. All Pulling vehicles must be an equipped with a starter interrupter switch on the gearshift which will only allow starter engagement only in neutral gearshift position.
Seats and Fencers:
1. All seats must have no more than 2" behind rear of seat. A substantial backrest made of 1/2" cross section of steel or metal equal in strength with a minimum 4" wide and 6" long pad firmly attached, or a manufactured seat equal in strength.
2. Fenders to consist of barrier between driver and tire fender to be a minimum of 1" over height of tire, fender to curl 4" horizontally from vertical edge over the tire, in the same configuration as the tire. Minimum length of 18" at the top of the fender. Must be able to support the weight of driver. Fenders or tire shields must be constructed so that when the driver is seated and hands are on the wheel, he/she cannot touch the rear tire with any part of his or her body.
id pads to be a minimum of 1/2 the tire diameter length when measured from rear axle center line to rear of pad. Pad to be 6" (maximum) above ground. One skid pad or wheels to be on each side of the tractor, the combination strong enough to support the weight of the tractor.heels or sk
1. No dual tires, tire studs or chains permitted. All power must be transmitted through the wheels.
2. Rim size to be 16" diameter, maximum width of lugs to be no wider than that of factory manufactured 18.4X16.1 tire. No tire repairs (boots, section repair, vulcanized spots, etc.) to be allowed.
Clutches, Flywheels & Automatics
1. The use of torque converters, automatic shifts, etc., will be permitted.
2. All auto transmissions and torque converters will be covered with a blanket meeting current SF1 specifications or 2 blankets meeting SEMA approved specifications. Blanket is to extend must be fastened forward securely w/2 straps on each side. 1" above crank-shaft center line & 1 below crankshaft center line. Blanket should have 6" of overlap, straps must be 2" wide w/not more than 1" spacing between each strap.
3. All pulling vehicles using an auto transmission must be equipped with a positive reverse gear lockout.
4. All pulling vehicles using a clutch will be required to have SF1 approved steel plate or steel billet flywheel.
6. No chemical milling allowed.
7. There shall be twelve 5/16" grade 5 or better cap screws securing the cover to the bell housing. The cover must have a plate or fillet that fits flush inside of the housing. The cover and fillet must be steel. The fillet must be welded to the cover and all bolts must be flush to the inside.
8. There must be four bolts used to secure the transmission to the bell housing 1/2" minimum diameter.
9. All bell housings must be flush on the inside surface.
10. All automotive type engines with bell housing and clutch will run a full lock plate. Either a commercially available unit, or minimum 3/16" steel or 1/4" aluminum with five 3/8" grade S bolts evenly spaced on the bottom of the bell housing.
1. Stabilizer bar system must be able to support the weight of the tractor in the heaviest class pulled.
2. Stabilizer bars are required. The draw bar & draw bar assembly will not in any way be attached to stabilizer bar assembly. Device is to have wheels or a skid plate. Wheels are to be at least 1" wide & S' in diameter. Skid pads to be at least 4" square at ground contact point.
Drive line Shielding
1. All remaining drive train, excluding any additional manual transmissions, must be enclosed in 5/16" minimum steel or 3/8" aluminum round inside diameter not to exceed 2" more than the outside diameter of the largest universal joint fastened every 6" or closer with 3/8" or larger bolts grade 5 or butt and seam welded and securely mounted to vehicles frame. Applies to all vehicles with exposed drive shaft. No more than 1/4" of end of drive line shall be visible with drive line shielding in place. Note: If U-joints are used in any drive shaft application the shielding must be 5/16" steel or 3/8" aluminum with 1/8" steel insert in aluminum. The insert must be a minimum of 6" wide.
2. The opening at the bottom of the transmission/torque converter housing must be enclosed in steel (stock cover is acceptable).
3. All mini tractor engine/automatic transmissions combinations must have two front motor mounts. Two rear motor mounts and a support saddle for rear of the transmission with 1/2" maximum clearance; Or
4. Two front motor mounts, support saddle at rear of engine with 1/2" clearance and a mount at rear of transmission. This is to prevent engine or transmissions from dropping if breakage occurs.
1. All competing vehicles must be equipped with working rear wheel brakes.
2. All drive line must have 3/8" steel, 360 degrees around brake components and ends must be closed with 1/8" steel or greater.
1. Draw bars cannot be shorter nor higher than specifications listed below. Draw bar lengths are measured from the center of the rear wheels to the point of hook.
a. DRAW BAR HEIGHT 13"
b. Draw bar length 6"
2. Draw bars to be rigid with no movement allowed. Draw bars must have the pivot pin on the same plane as the hitch point and to the ground within 1-1/2” plus or minus per foot of length. This formula translates to a legally allowed 10 degrees or less of the draw bar angle.
3. All draw bars and hitching devices will be steel.
4. Mini draw bar and hitching deice to be one piece totally constructed with minimum of 1-inch solid steel material. No hollow tubing is permitted. Front point CF draw bar is to have a minimum of 1/2 inch cross sectional. Thickness remaining where hole is drilled minimum 1/2-inch pin. Draw bar height adjusting bolts to be 5 inches or less from hooking point the front point of hook is to have a minimum of a 2-inch round hole. Maximum 2-1/4 hold. The thickness of material around the hole must be a minimum 3/4-inch-thick and point of hook to be no more than 3/4-inch cross sectional thickness at back edge.
The follow may be used instead of 4
Mini tractor draw bars must be equipped with a hitching device 3/4" thick and must have a min. 2' round hole pulling point must be 3/4" from back edge of hitching device cross sectional thickness of 3/4" square steel or 7/8" round with a 1/2" steel pin. Draw bar height adjusting bolts to be 5" or less from the hooking point. All mini tractors will be required to have a draw bar restraint cable consisting of a min. of 1/2 all steel cable and 2-1/2" clamps to join cable together. Cable to go around further most back point of hitching device & go around axle tires and over rear end housing and be joined with 2 1/2 cable claws. Cable to be installed as tightly as possible to prevent a sudden jerk if draw bar breaks. Cable may be held up around back of hitching device with plastic cable ties in such a manner as not to interfere with the sled hook when being hooked up.
5. No portion of vehicle may interfere with sled, chain or hook during a pull or while being hooked or unhooked.
6. Areas 6" wide and 12" high immediately above the draw bar must be free of all obstructions (including weights, wheelie bars) for ease of hooking and unhooking.
7. Draw bars to have no provisions to be made shorter than the legal length.
8. Draw bars and wheelie bars are not to be connected.
9. No trick hitches. No cam type rear ends. Draw bar distance from center of rear axle cannot change during pull. Draw bar must be rigid in all directions.
10. All vehicles are required to have a tow hitch on the front of their vehicle.
Mini Modified Adding Weights
1. Weights must be securely fastened.
2. No transfer of weights while vehicle is in motion will be allowed
3. Weights must not extend rearward beyond the rear tires.
4. Any ballast lost while hooked to the sled and under the green flag will be cause for disqualification. A weight touching the ground although it may still be attached to the pulling vehicle. Will be cause for disqualification (internal break age excepted).
5. Weight must not interfere with the kill switch, draw bar, or chain.
1. All tractors will use a one-piece solid steel harmonic balancer or an SF1 approved unit.
2. All tractors using a flywheel will use a steel billet unit or a SF1 approved unit.
3. All fire suits will meet SF1 Specs.
4. All clutches and pressure plates will meet SF1 specs or a blanket meeting SEMA or NHRA specs will be used over a safety bell housing meeting SF1 spec 6.1
5. All tractors using standard transmissions will use a bell housing meeting SF1 specs 6.1. A block saver plate of 3/16 steel or 1/4 aluminum will be used on bottom 1/2 of bell housing. If no clutch pedal is used this area will be filled in with a fillit of the same material & thickness that the bell housing is made of. The fillit will be bolted in with a minimum of (5) 5/16 grade 5 bolts. The bell housing cannot be altered from original manufacturer. If clutch pedal is used a shield will be used to enclose this are to keep any material from coming out. This will be of 5/16 steel or 3/8 aluminum.