THOMPSON INTERNATIONAL SPEEDWAY

2004

LATE MODEL RULES

BODY:

GENERAL: 1978 & NEWER AMERICAN CARS WITH A 108” WHEELBASE. OEM STOCK OR   AFTERMARKET STEEL, ALUMINUM OR FIBERGLASS BODIES ALLOWED. STOCK DIMENSIONS ONLY. NO “DIRT” OR “OUTLAW” BODIES OR BUMPER COVERS ALLOWED. NO STRAIGHT OR SLAB SIDE BODIES. NO OFFSET BODIES. REAR QUARTER WINDOW PANEL(C PILLAR) MUST MEET QUARTER PANEL. NO SHELVES. BODIES MUST BE CENTERED ON THE FRAME. THE FRONT & REAR BUMPER COVERS MUST MATCH BODY BEING USED. REAR BUMPER COVER/TAIL PANEL MUST REMAIN UNCUT AND MAY NOT HAVE ANY HOLES. IF AFTERMARKET BUMPER COVERS ARE USED, BUMPER TUBING MUST BE INSIDE OF COVER AND MAY NOT EXTEND PAST THE FLAT SURFACE OF THE TIRE. NO LOWERING, CHOPPING, OR CHANNELING OF ANY BODY PARTS. NO “BELLY PANS” OR ANY UNDER CAR AERODYNAMICS ALLOWED. ROCKER PANEL OR SIDE SKIRTS MAY NOT BE ROLLED UNDER. BODY MUST MATCH MOTOR BEING USED.  LISTED BELOW ARE THE ONLY APPROVED AFTERMARKET BODIES:

BUICK REGAL, OLDS CUTLASS, PONTIAC GRAND PRIX, CHEVY MONTE CARLO, CHEVY LUMINA, FORD TAURUS, FORD T-BIRD, CHRYSLER LEBARON, DODGE AVENGER, DODGE INTREPID.

NO CARBON FIBER OR TITANIUM ENGINE, POWER TRAIN, BODY OR CHASSIS PARTS!

MAXIMUM FRONT OVERHANG: 45” MEASURED FROM THE CENTER OF THE SPINDLE TO FRONT OF BUMPER.

MINIMUM ROOF HEIGHT: 46” MEASURED 10” BACK FROM TOP OF THE WINDSHIELD. 46” MEASURED 6” FROM THE TOP OF THE REAR WINDOW.

MINIMUM WINDSHIELD ANGLE: 25 DEGREES MEASURED ANYWHERE IN THE CENTER OF THE WINDSHIELD.

MAXIMUM VENT WINDOW: 10” MEASURED FROM THE BASE OF THE A PILLAR. VENT WINDOW MAY NOT BE  TAPERED BACK, MUST GO STRAIGHT UP TO PILLAR.

MAXIMUM B POST EXTENSION: 3” MEASURED FROM CORNER OF BODY.

MAXIMUM DECK LID HEIGHT: 35” MEASURED AT TOP OF REAR QUARTER/DECK LID.

MAXIMUM REAR OVERHANG: 52” MEASURED FROM CENTER OF REAR AXLE TO END OF BUMPER.

MAXIMUM REAR SPOILER: 5” HEIGHT BY 60” LENGTH.

MAXIMUM SPOILER HEIGHT: 40” MEASURED FROM TOP OF SPOILER TO GROUND.

GLASS: FULL WINDSHIELD AND BACK GLASS. QUARTER GLASS AND VENT WINDOWS ALLOWED.

BODY SPOILER: SIDE SKIRTS ALLOWED BETWEEN WHEEL OPENINGS. MUST FOLLOW CONTOUR OF BODY AND MAY NOT BE STEPPED OR ANGLED. SIDE SKIRTS MUST MAKE RIDE HEIGHT.

INTERIOR SHEETMETAL: FIREWALLS MUST BE WELDED. THE FRONT FIREWALL CANNOT BE FURTHER BACK THAN THE CENTERLINE BETWEEN THE FRONT UPRIGHT LEGS OF THE ROLL CAGE. A FOOTBOX MAY BE USED. A FILLER PANEL MUST BE USED BETWEEN THE FIREWALL (ROLL CAGE UPRIGHT) TO THE RIGHT DOOR. THIS PANEL MUST BE STRAIGHT TO THE FRAME RAIL (NO BENDS OR CURVES). THE REAR FIREWALL CANNOT BE FURTHER FORWARD THAN THE CENTERLINE OF THE MAIN HOOP BAR OF THE ROLL CAGE.  A FULL STOCK APPEARING FLOOR MUST BE USED. RIGHT SIDE FLOOR MAY RUN LEVEL ACROSS FROM THE TUNNEL TO THE RIGHT DOOR PANEL. ALL INTERIOR SHEETMETAL MUST BE  .031”  STEEL.

FRAME/CHASSIS:

MUST BE A PERIMETER FRAME. NO OFFSET OR STRAIGHT RAIL FRAMES ALLOWED.

G-METRIC CHASSIS CARS WILL BE ALLOWED TO CLIP TUBE SNOUTS. CENTER SECTION AND REAR CLIP MAY BE OEM STOCK OR CONFORM TO THE TUBULAR SECTION OF THE RULES.

FRONT SNOUTS: MAY BE OEM OR FABRICATED. (SEE LIST OF APPROVED SNOUTS).

OEM SNOUTS: STOCK FRONT SUB-FRAME BEGINNING A MINIMUM OF 22 INCHES REARWARD OF THE CENTERLINE OF THE FRONT SPINDLES AND EXTENDING FORWARD TO IN FRONT OF THE RADIATOR MUST REMAIN STOCK OEM. THE ONLY MODIFICATIONS PERMITTED ARE FOR SPRING BUCKET/JACKING BOLT, UPPER A-FRAME PERCH AND THE BOTTOM OF THE CROSS MEMBER MAY BE CUT FOR OIL PAN, HEADER & FUEL PUMP CLEARANCE. THE CROSS MEMBER MUST NOT BE MOVED FROM ITS ORIGINAL LOCATION. A MAXIMUM DISTANCE OF 25” MUST BE MAINTAINED FROM THE LEADING EDGE OF THE CENTER SECTION KICKOUT TO THE CENTERLINE OF THE FRONT CROSS MEMBER. STOCK OEM LOWER CONTROL ARMS. CONTROL ARMS MUST MATCH THE SNOUT BEING USED. BUSHINGS MAY BE CHANGED, BUT CANNOT BE OFFSET. BALL JOINTS MAY BE CHANGED, BUT MUST STAY IN STOCK OEM POSITION. NO REPOSITIONING, ELONGATING OR OVERSIZING OF ANY MOUNTING HOLES. THE FOLLOWING ARE THE ONLY APPROVED OEM SNOUTS:

GM: G-METRIC & CAMARO

FORD: 79 AND NEWER FULLSIZE LTD, CROWN VIC. FORD MAY ALSO USE G-METRIC OR CAMARO.

CHRYSLER: 79 AND NEWER FULL SIZE. CHRYSLER  MAY ALSO USE A G-METRIC OR CAMARO.  

TUBULAR SNOUT: 

GM-TYPE FRONT STEER TUBULAR FRONT SUB-FRAME MUST BE CONSTRUCTED USING 2” X 4” MAGNETIC STEEL TUBING WITH A MINIMUM .083” WALL THICKNESS. ALL FRONT STEER ASSEMBLIES MUST MAINTAIN A DIMENSION OF 32” FROM THE CENTER OF THE LEFT SIDE RAIL TO THE CENTER OF THE RIGHT SIDE RAIL AT ANY POINT FROM THE FRAME SIDE RAIL KICK OUTS EXTENDING FORWARD IN FRONT OF THE STEERING ASSEMBLY. THE FRONT FRAME EXTENSIONS USING 2” X 3” MINIMUM .083” MAGNETIC STEEL TUBING MAY BE WELDED TO THE END OF THE SUB-FRAME BUT SHOULD ANGLE DOWN A MAXIMUM OF 18 DEGREES. THE FRONT SUB-FRAME MUST BE ATTACHED IN THE CENTER OF THE FRAME AT THE FRAME SIDE RAIL KICK OUTS AND EXTEND FORWARD A LENGTH OF 16” ON ONE SIDE WITH THE OPPOSITE SIDE NO MORE THAN 1 INCH DIFFERENCE AND ANGLE UPWARD AT BETWEEN 22 AND 25 DEGREES. AT THIS POINT, A PIECE OF TUBING 27 INCHES LONG MUST BE WELDED AND EXTENDED STRAIGHT FORWARD IN FRONT OF THE STEERING ASSEMBLY. A DISTANCE OF 25” MUST BE MAINTAINED FROM THE LEADING EDGE OF THE KICKOUT TO THE CENTERLINE OF THE FRONT CROSS MEMBER. THE FRONT CROSS MEMBER MUST BE CONSTRUCTED USING 2” X 3” MINIMUM .083” MAGNETIC STEEL TUBING. THE MOUNTING POINTS FOR THE LOWER A-FRAMES MUST BE 14 Ό” AT THE REAR AND 8 Ύ” ON THE FRONT, MEASURED FROM THE CENTERLINE OF THE SUB-FRAME TO THE CENTERLINE OF THE MOUNTING HOLE. WHEN MEASURING EITHER THE LEFT OR RIGHT SIDE, THE DISTANCE FROM THE CENTERLINE OF THE BOTTOM BALL JOINT TO THE CENTERLINE OF THE SUB-FRAME MUST BE EQUAL.

FORD TYPE  REAR STEER TUBULAR FRONT SUB-FRAME MUST BE CONSTRUCTED USING 2” X 4” MAGNETIC STEEL TUBING WITH A MINIMUM .083” WALL THICKNESS. ALL REAR STEER ASSEMBLIES MUST MAINTAIN A DIMENSION OF 32” FROM CENTER OF THE LEFT SIDE RAIL TO THE RIGHT SIDE RAIL AT ANY POINT FROM THE REAR OF THE SPRING MOUNT TO THE FRONT OF THE SUB-FRAME ASSEMBLY. A DISTANCE OF 34” MUST BE MAINTAINED FROM THE FRAME SIDE RAIL KICK OUTS FORWARD TO THE REAR OF THE TOP SPRING MOUNTING PLATE MEASURED CENTER TO CENTER. THIS WILL BE DONE BY MOVING THE LEFT SIDE FRAME SECTION OUT 2” TO PERMIT MOUNTING SPACE FOR THE STEERING BOX AND MAINTAINING THE CENTER TO CENTER DISTANCE OF 34”. THE FRONT SUB-FRAME ASSEMBLY BE ATTACHED IN THE CENTER OF THE FRAME AT THE FRAMESIDE RAIL KICK OUTS AND EXTEND UPWARD & FORWARD, 19 ½”, TO THE REAR OF THE TOP SPRING MOUNT PLATE BETWEEN A 22 AND 25 DEGREE ANGLE. THE TOP SPRING MOUNT PLATE SHALL EXTEND FORWARD 7 Ό”. A PIECE OF TUBING 21 ½ “ LONG MUST BE WELDED AT THE FRONT OF THE SPRING MOUNT AND ANGLE DOWN A MAXIMUM OF 18 DEGREES. A DISTANCE OF 21 5/8” MUST BE MAINTAINED FROM THE LEADING EDGE OF THE KICKOUT TO THE CENTERLINE OF THE FRONT CROSS MEMBER. THE MOUNTING POINTS FOR THE LOWER A-FRAMES MUST BE 8”, MEASURED FROM THE CENTER OF THE SUB-FRAME TO THE CENTERLINE OF THE MOUNTING HOLE. STRUT RODS MUST BE BOLTED IN STOCK LOCATION ON THE LOWER A-FRAMES AND EXTEND FORWARD AND MOUNTED ON A CROSS MEMBER. WHEN MEASURING EITHER THE RIGHT OR LEFT SIDE, THE DISTANCE FROM THE CENTERLINE OF THE BOTTOM BALL JOINT TO THE CENTERLINE OF THE SUB-FRAME MUST BE EQUAL.

CENTER SECTION: THE CENTER SECTION OF THE CHASSIS MUST BE CONSTRUCTED WITH MINIMUM 2” X 3” X .120” MAGNETIC STEEL TUBING. THE WIDTH OF THE SIDE RAILS MUST BE A MAXIMUM OF 60” MEASURED FROM OUTSIDE OF RAIL TO OUTSIDE OF RAIL. BOTH RAILS MUST BE OF EQUAL LENGTH AND CENTERED.

REAR CLIP: THE REAR SECTION MUST BE CONSTRUCTED WITH MINIMUM 2” X 3” X .083” MAGNETIC STEEL TUBING. THE REAR SECTION MUST BE CENTERED TO THE CENTER SECTION OF THE CHASSIS. THE REAR RAILS MUST BOTH MAINTAIN THE SAME ANGLES AND MUST BE SYMETRICAL IN DESIGN. THE RAILS MUST GO OVER THE REAR END ASSEMBLY AND MUST MAINTAIN A MINIMUM GROUND CLEARANCE OF 10” AFTER THE REAR END. A REINFORCEMENT BAR (CRASH BAR), MINIMUM 1 ½” DIAMETER, .083” THICKNESS, MUST EXTEND BELOW THE REAR FRAME SECTION BEHIND THE FUEL CELL. THIS REINFORCEMENT BAR MUST BE AS WIDE AS THE FRAME RAILS AND EXTEND AS LOW AS THE BOTTOM OF THE FUEL CELL WITH 2 VERTICAL UPRIGHTS EVENLY SPACED IN BETWEEN THE FRAME RAILS AND ATTACHED TO THE REAR REINFORCEMENT BAR. TWO (2) SUPPORT BARS, ONE (1) LOCATED ON EACH CORNER, MUST ANGLE UPWARDS AND BE WELDED TO THE FRAME RAILS.

ROLL CAGE: THE FOLLOWING ARE ADDITIONAL REQUIREMENTS AND CLARIFICATIONS FOR THE INSTALLATION OF THE ROLL BARS. THE MAIN ROLL BAR REFERRED TO AS #1 MUST BE MOUNTED VERTICAL (90 DEGREES) ON THE CENTER SECTION OF THE FRAME WITH NO OFFSET. THIS BAR MUST BE CENTERED TO THE CHASSIS. THE CENTER OF THE TOP OF THIS BAR MUST BE NO LOWER THAN 36 ½” FROM THE TOP OF THE FRAME RAIL. LOCATION OF THE MAIN BAR IS A MAXIMUM OF 85 ½” AS MEASURED FROM THE CENTERLINE OF THE LOWER BALL JOINT TO THE CENTERLINE OF THE MAIN BAR. THE ROOF BAR REFERRED TO AS #3 MUST BE WITHIN 4” OF THE SIDE WINDOW AND/OR DOOR OPENINGS ON BOTH SIDES, AS WELL AS THE FRONT WINDSHIELD, WITH NO OFFSETS. THE CENTER OF THE FRONT UPRIGHT LEGS REFERRED TO AS #2A AND #2B CAN NOT BE FURTHER BACK THAN 39” FROM THE CENTER OF THE LOWER BALL JOINTS. POSITIVELY NO OFFSET ROLL CAGES !!!

WHEELBASE: 108”.

FUEL CELL HEIGHT: 8” MINIMUM.

BALLAST WEIGHT: ALL BALLAST WEIGHT MOUNTED TO THE OUTSIDE OF THE FRAME MAY NOT EXCEED 3” FROM THE FRAME.

GROUND CLEARANCE: 4”

CAR WEIGHT:  MINIMUM 2950 LBS., MAXIMUM LEFT SIDE PERCENTAGE 56.0%.

SUSPENSION:

A-FRAMES: UPPER A-FRAME MAY BE AFTERMARKET OR OEM. AFTERMARKET A-FRAME MUST HAVE A CROSS-SHAFT. LOWER A-FRAMES MUST BE STOCK OEM AND MATCH THE SNOUT BEING USED. LOWER A-FRAME MUST MOUNT IN STOCK OEM LOCATION. BUSHINGS MAY BE CHANGED BUT CANNOT BE OFFSET. BALL JOINTS MAY BE CHANGED BUT MUST REMAIN IN ORIGINAL OEM POSITION.

GM TUBULAR SNOUT MUST USE A CHEVROLET IMPALA LOWER CONTROL ARM.

SPINDLE & HUBS: AFTERMARKET OR OEM STEEL SPINDLES. SPINDLES MUST HAVE A STOCK PIN. SPINDLES MUST MATCH LEFT TO RIGHT WITH NO OFFSET, INCLUDING HEIGHT AND INCLINATION. STOCK TYPE STEEL ROTORS AND HUBS MUST BE USED. NO WIDE FIVE OR G.N. HUBS.

BRAKES: MUST BE OPERATIONAL ON ALL 4 WHEELS AT ALL TIMES. VALVES OF ANY TYPE WILL NOT BE PERMITTED IN THE BRAKE LINES THAT WILL REDUCE OR STOP THE FLOW OF BRAKE FLUID TO A SINGLE WHEEL.  DISC BRAKES ALLOWED, FRONT AND REAR. STOCK OR AFTERMARKET STEEL PIN TYPE SINGLE PISTON CALIPERS. NO ALUMINUM CALIPERS. FRONT STEEL STOCK TYPE ROTOR & HUB ALLOWED. REAR ROTORS MUST BE MINIMUM .810” X 11” STEEL AND USE A STEEL HAT. AFTERMARKET MASTER CYLINDER (S) AND PEDALS ALLOWED.  OEM MASTER CYLINDER MUST BE A DUAL RESERVOIR TYPE. ADJUSTABLE  PROPORTIONING VALVE MAY BE USED. NO DRILLING OR LIGHTENING OF DRUMS, ROTORS OR CALIPERS.

STEERING: STOCK OEM STEERING, AND STEERING BOX FOR CHASSIS BEING USED. NO RACK & PINION STEERING. HEIM JOINTS MAY BE USED AT THE INNER & OUTER TIE ROD ENDS. CENTER LINK MUST BE STEEL AND STOCK APPEARING. COLLAPSIBLE STEERING SHAFT IS RECOMMENDED. IF COLLAPSIBLE STEERING SHAFT IS NOT USED, THEN THE SHAFT MUST BE MADE WITH AT LEAST 2 U-JOINTS AND INSTALLED SO THAT UPON A HEAVY FRONT END COLLISION THE SHAFT WILL DEFLECT TO THE SIDE.

SPRINGS & SHOCKS: STOCK TYPE STEEL MINIMUM 5” SPRINGS MOUNTED IN ORIGINAL OEM LOCATION. IF LEAF SPRINGS ARE USED, ALL LEAFS MUST BE STEEL AND THE SAME WIDTH. NO HELPER SPRINGS OR TRACTION BARS. REAR SPRINGS MUST BE CENTERED OVER THE REAR END AND EQUALLY SPACED FROM CHASSIS CENTERLINE. CENTERLINE OF THE SPRING MAY NOT EXCEED THE CENTERLINE OF THE FRAME RAILS. ONLY ONE (1) STEEL OR ALUMINUM BODIED SHOCK PER WHEEL. SHOCKS (INCLUDING ENDS), MAY NOT EXCEED RACERS NET PRICE OF $165.00 PER SHOCK ASSEMBLY.  REAR SHOCKS MUST MOUNT IN STOCK LOCATION. NO ADJUSTABLE, LOAD LEVELER, OFF ROAD, AIR TYPE OR SHOCKS WITH EXTERNAL RESERVOIRS OR REMOTE/ELECTRONICALLY CONTROLLED SHOCKS ALLOWED. NO COIL OVER ELIMINATORS.

REAR SUSPENSION: TRAILING ARMS MAY USE  HEIM JOINTS. MAXIMUM LENGTH OF ARM MEASURED FROM CENTER TO CENTER OF MOUNTING HOLES, NOT TO EXCEED 25”. STOCK TRAILING ARMS MAY USE AFTERMARKET BUSHINGS, HOLES MAY NOT BE OFFSET. 3 LINK REAR, THE UPPER LINK MAY USE HEIM JOINTS OR RUBBER BUSHINGS. NO HORIZONTAL SPRINGS OR ANY OTHER TORQUE ABSORBING DEVICES. THE CENTER OF THE FORWARD MOUNTING POINT CAN BE NO FURTHER FORWARD THAN 13” FROM THE VERTICAL CENTERLINE OF THE REAR AXLE.

PANHARD BAR: ONE SINGLE PANHARD BAR MAY BE USED. IT MUST BE MOUNTED BEHIND THE REAR AXLE ASSEMBLY.

WHEELS: 8” STEEL, MINIMUM 19 LBS RACING WHEELS WITH REINFORCED CENTERS ARE MANDATORY.

OEM SNOUTS; BOTH FRONT WHEELS MUST HAVE THE SAME OFFSET. BOTH REAR WHEELS MUST HAVE THE SAME OFFSET. THE FRONT AND REAR OFFSETS DO NOT HAVE TO MATCH.

TUBE SNOUTS; ALL FOUR WHEELS MUST HAVE THE SAME OFFSET.

WHEEL OFFSET IS MEASURED OFF THE INSIDE BEAD SEAT TO THE INSIDE MOUNTING FLANGE OF THE WHEEL.

WHEEL SPACERS: MAY BE USED ON OEM SNOUTS TO OBTAIN TREADWIDTH. BOTH FRONT SPACERS MUST BE SAME THICKNESS. BOTH REAR SPACERS MUST BE THE SAME THICKNESS.

TUBE SNOUTS; WHEEL SPACERS ARE NOT ALLOWED.

TREADWIDTH: MAXIMUM FRONT & REAR 76”.

TIRES: AMERICAN RACER 8” SLICK. LEFT SIDE TIRE IS EC-84, 26.5 X 8.0 X 15S. RIGHT SIDE TIRE IS EC-85, 27.0 X 8.0 X 15S.

ENGINE:

GENERAL SPECS: MUST BE STOCK OEM V8 PRODUCTION CAST IRON BLOCKS AND CYLINDER HEADS. THE BLOCK MUST RETAIN ALL OEM SPECS WITH THE EXCEPTION OF CYLINDER OVERBORE AND SURFACING OF THE BLOCK. ANGLE CUTTING OF THE BLOCK DECK WILL NOT BE PERMITTED. ORIGINAL BORE & STROKE MUST BE MAINTAINED. CYLINDERS MAY BE BORED A MAXIMUM OF .040” FROM STANDARD SIZE.  AFTERMARKET OEM TYPE MAGNETIC STEEL MAIN BEARING CAPS ALLOWED. MUST BE STOCK APPEARING. NO SPLADE CAPS ALLOWED. NO DEBURRING, GRINDING, CHEMICAL (ACID MILLING), OR ABRASIVE CLEANING OF ANY ENGINE PARTS. NO COATING (EX. TEFLON), PLATING (EX. CHROMING), OR PAINTING OF ANY INTERNAL ENGINE PARTS. OIL RETURN HOLES MAY BE DEBURED AND/OR COVERED WITH SCREENS. EPOXYING MAGNETS TO THE OIL RETURN AREA IS ALLOWED. NO CARBON FIBER ENGINE PARTS. NO  PUMPS OF ANY TYPE ALLOWED IN THE EVACUATION SYSTEM. THE ONLY APPROVED ENGINES ARE; CHEVROLET-350, CHRYSLER-340 OR 360, FORD-351C OR 351W.

COMPRESSION: MAXIMUM COMPRESSION IS 10.5:1, CHECKED WITH THE “WHISTLER”. NO TOLERANCE ALLOWED ON MAXIMUM COMPRESSION! THE 2 MOST FORWARD BOLTS ON EACH SIDE OF THE INTAKE MUST BE DRILLED TO ACCEPT A SEAL.

LOCATION: GENERAL MOTORS; THE CENTER OF THE FORWARD MOST SPARK PLUG MUST BE EVEN WITH OR FORWARD OF THE CENTERLINE OF THE UPPER BALL JOINTS. FORD AND CHRYSLER; THE RIGHT CYLINDER HEAD MUST BE EVEN OR FORWARD OF THE CENTERLINE OF THE UPPER BALL JOINTS. ENGINE MUST BE CENTERED IN THE CHASSIS. ENGINE MUST BE LEVEL AS MEASURED FROM SIDE TO SIDE AND FRONT TO BACK WITHIN ½”. MINIMUM CRANKSHAFT HEIGHT IS 11” MEASURED FROM THE CENTERLINE OF THE CRANKSHAFT TO THE GROUND.

CRANKSHAFT: ONLY STOCK PRODUCTION OEM CRANKSHAFTS ALLOWED. CHEVROLET MUST USE LARGE JOURNAL CRANK. REGRINDING OF THE ROD AND MAIN JOURNALS TO A MAXIMUM OF .030” UNDER STANDARD SIZE IS ALLOWED. THE MAXIMUM ALLOWABLE STROKE TOLERANCE FOR CHEVROLET IS +/- .015”. MAXIMUM STROKE ON A CHEVROLET WILL BE 3.495”. MAXIMUM STROKE ON CHRYSLER WILL BE 3.580”,  +/- .005”. MAXIMUM STROKE ON FORD WILL BE 3.500”, +/- .005”.  THE ROD JOURNALS MAY BE DRILLED TO OBTAIN THE MINIMUM CRANKSHAFT WEIGHT. NO MACHINING, POLISHING, GRINDING OR ANY OTHER MODIFICATIONS TO ANY PART OF THE CRANKSHAFT ALLOWED. CRANKSHAFT MUST REMAIN AS MANUFACTURED. ONLY NORMAL OEM TYPE ENGINE BALANCING ALLOWED. MINIMUM CRANKSHAFT WEIGHT IS 50 LBS. CHRYSLER MAY USE PART# P5007253AB. FORD MAY USE PART# M-6303-H351.

PISTONS & RODS: FLAT TOP 3–RING ALUMINUM PISTONS ONLY. ALL 3 RINGS MUST BE OF MAGNETIC STEEL. VALVE RELIEF MAY BE CUT INTO THE PISTON. NO PART OF THE PISTON MAY PROTRUDE ABOVE THE TOP OF THE BLOCK. ANY STEEL PISTON RINGS ALLOWED. STOCK TYPE STEEL RODS ONLY. ALL AFTERMARKET RODS MUST BE SOLID BEAM TYPE “SPORTSMAN” ROD. NO HOLLOW BEAM RODS. NO BILLET RODS. MINIMUM ROD LENGTH 5.700”, MAXIMUM ROD LENGTH 6.250”. ALL RODS MUST BE THE SAME LENGTH. MINIMUM WEIGHT FOR PISTON, PIN, RINGS, BEARING & ROD ASSEMBLY IS 1075 GRAMS.

CAMSHAFT: NO ROLLER OR MUSHROOM CAMSHAFTS. NO GEAR OR BELT DRIVEN CAMSHAFTS. ANY TIMING CHAIN MAY BE USED.

VALVE LIFTERS:  STOCK DIAMETER LIFTERS ONLY.  NO ROLLER OR MUSHROOM LIFTERS ALLOWED.  ANY TYPE OF MECHANICAL ASSISTANCE EXERTING A FORCE TO ASSIST IN CLOSING OF THE LIFTER AND/OR PUSHROD (REV KITS) ARE NOT ALLOWED.  ONLY MAGNETIC STEEL STRAIGHT BARREL LIFTERS WILL BE ALLOWED IN 2005.

ROCKER ARMS: ROLLER ROCKER ARMS ARE PERMITTED. ROCKERS MUST BE INDEPENDENT AND STUD TYPE. NO STUD GIRDLES OR SHAFT ROCKERS. CHRYSLER MAY USE OEM SHAFT SYSTEM.

CYLINDER HEADS: STOCK OEM CAST IRON PRODUCTION HEADS ONLY, LIMITED TO 2 VALVES PER CYLINDER. FORD WINDSOR MAY USE THE CAST IRON “WORLD PRODUCTS WINDSOR JR” CYLINDER HEAD. BARE CASTING PART# 05303B WITH 1.94” INTAKE VALVE AND 1.60” EXHAUST VALVE. THIS IS THE ONLY APPROVED AFTERMARKET CYLINDER HEAD! NO PORT MATCHING OR FLOW WORK. NO GRINDING, POLISHING, BEADING OR CHEMICAL (ACID) MILLING ALLOWED. CHEVROLET MUST USE STRAIGHT PLUG HEADS WITH A 2.020” OR SMALLER INTAKE VALVE, EXHAUST VALVE MAXIMUM SIZE IS 1.60”. NO BOWTIE OR VORTEC HEADS ALLOWED. CHRYSLER MUST USE PART # P5249574 CASTING # 4772576 OR 448308 CYLINDER HEAD WITH A 2.020” OR SMALLER INTAKE VALVE, EXHAUST VALVE MAXIMUM SIZE IS 1.60”. CHRYSLER MAY ALSO USE PART# P5007086 CASTING # 53021137 OR 53006673. NO W-2 HEADS ALLOWED. FORD WINDSOR MUST USE HEADS WITH A 1.94” OR SMALLER INTAKE VALVE, EXHAUST VALVE MAXIMUM SIZE 1.60”.  FORD CLEVELAND MUST USE HEADS OF  2 BARREL DESIGN WITH 2.050” OR SMALLER INTAKE VALVE, MAXIMUM EXHAUST VALVE IS 1.660”. FORD MOTORSPORTS HEADS ARE NOT ALLOWED.

VALVES: MUST BE STOCK OR DIRECT REPLACEMENT. STAINLESS STEEL ALLOWED. OVERSIZE STEMS ALLOWED. NO PART OF THE VALVE STEM MAY BE SMALLER THAN STOCK, EXCEPT FOR THE KEEPER GROOVES. NO “PR FLO”, TULIP, ULTRA LITE OR TITANIUM VALVES. VALVES MAY BE COATED OR PLATED (EX. TEFLON).

VALVE SPRINGS: MAXIMUM OUTSIDE DIAMETER OF 1.55”. MAXIMUM INSTALLED HEIGHT OF 1.90”. NO TITANIUM OR ALUMINUM RETAINERS.

VALVE JOB: MULTI ANGLE VALVE JOBS ARE PERMITTED. WHEN CUTTING THE VALVE SEAT ANGLES, NO STONE OR GRINDING MARKS ARE PERMITTED ABOVE THE BOTTOM OF THE VALVE GUIDE. ALL CUTTING IN REFERENCE TO THE VALVE JOB AND BOWL AREA MUST BE CENTERED OFF THE CENTERLINE OF THE VALVE GUIDE. ON THE BOWL SIDE OF THE INTAKE AND EXHAUST SEATS, THE MAXIMUM ANGLE OF CUTTING AND/OR GRINDING WILL BE 90 DEGREES. UPON COMPLETION OF THE VALVE JOB, THE BOWL AREA UNDER THE VALVE SEAT DOWN TO THE VALVE GUIDE MUST STILL BE THE SAME CONFIGURATION AS FAR AS SHAPE AND FINISH AS IT WAS FROM THE MANUFACTURER. SURFACE AND/OR EDGES WHERE THE CUTTER OR STONE HAS TOUCHED MUST NOT BE POLISHED. HAND GRINDING OR POLISHING WILL NOT BE PERMITTED ON ANY PART OF THE HEAD. NO WORK ALLOWED IN THE COMBUSTION CHAMBER, IT MUST REMAIN AS CAST FROM THE MANUFACTURER.

INTAKE MANIFOLD: EDELBROCK PERFORMER SERIES ARE THE ONLY INTAKES ALLOWED. THE INTAKE MUST REMAIN AS MANUFACTURED “STOCK OUT OF THE BOX”. MANIFOLDS MUST REMAIN UNALTERED, INCLUDING BOLT HOLES. PAINTING OR COATING OF THE INTAKE IS NOT ALLOWED. ONLY CURRENT DESIGNED INTAKES ALLOWED. OLDER INTAKES WITH CURRENT PART NUMBERS ARE NOT ALLOWED. APPROVED PART NUMBERS ARE; CHEVROLET 2101, FORD 2181, 2665, 2750, 7181, CHRYSLER 7176. CHRYSLER MUST USE INTAKE PART# P5007381 CASTING# P4510018 WITH CYLINDER HEAD PART # P5007086. A TRACK SUPPLIED INTAKE MUST FIT YOUR ENGINE.

CARB SPACER: ONE SOLID MATERIAL SPACER, MAXIMUM HEIGHT OF 1” PERMITTED. NO WEDGE SHAPE SPACERS ALLOWED. BOTH THE TOP AND BOTTOM SURFACES MUST BE PARALLEL. PORTHOLE (S) MUST BE VERTICAL TO THE TOP AND BOTTOM. NO BEVELING, TAPERING, FLARING OR RADIUSING OF PORTHOLE (S). SPACER MAY NOT BE STEPPED OR UNDERCUT. NO ADDITIONAL OPENINGS FOR THE INDUCTION OF AIR ALLOWED. ONLY ONE .075” MAX GASKET PER SIDE OF SPACER ALLOWED.

CARBURETOR: THE HOLLEY R4412 IS THE ONLY CARBURETOR ALLOWED. THE CARBURETOR MUST BE “STOCK OUT OF THE BOX”. ALL CARBURETORS MUST PASS TRACK SUPPLIED GAUGES. THE ONLY CHANGES THAT WILL BE ALLOWED ARE AS FOLLOWS; THE CHOKE PLATE AND SHAFT MAY BE REMOVED, JETS, POWER VALVE, ACCELERATOR PUMP CAM AND ACCELERATOR PUMP DISCHARGE NOZZLES MAY BE CHANGED. IDLE HOLES MAY BE DRILLED IN THROTTLE PLATES. THROTTLE PLATE SCREWS MAY BE TRIMMED FLUSH WITH SHAFT. NO OTHER CHANGES ALLOWED. NO RESHAPING, POLISHING, GRINDING, MACHINING OR DRILLING ALLOWED. NO ADJUSTABLE (JETTED) AIR BLEEDS OR CIRCUITS. METERING BLOCKS MUST REMAIN UNALTERED. GASKET MUST REMAIN UNALTERED. NO “HP” PARTS ALLOWED.

AIRCLEANER/FILTER: THE AIR CLEANER TOP AND BOTTOM MUST BE METAL. ALL AIR CLEANERS ARE SUBJECT TO TRACK APPROVAL. NO DUCTS, BAFFLES OR ANYTHING THAT MAY CONTROL AIRFLOW ALLOWED ON OR IN THE AIR CLEANER ASSEMBLY. ALL AIR ENTERING THE CARBURETOR MUST PASS THRU THE FILTER ELEMENT. NO AIR BOXES. A SHIELD MAY BE USED ON THE FRONT OUTER HALF OF THE ELEMENT IF PLACED DIRECTLY ON THE ELEMENT. AIR CLEANERS MUST REMAIN UNDER THE HOOD.

EXHAUST HEADERS: HEADERS MUST BE A COMMERCIALLY MANUFACTURED HEADER USING A STEEL PRIMARY TUBE SIZE OF 1 5/8” OUTSIDE DIAMETER, MAXIMUM 30” LENGTH WITH A COLLECTOR TUBE SIZE OF 3” OUTSIDE DIAMETER. THE HEADER COLLECTOR PIPE CANNOT BE REDUCED AT ANY POINT BETWEEN THE PRIMARY TUBE AND THE EXHAUST PIPE. PRIMARY TUBES MUST EXIT DOWN AND TURN TO THE REAR INTO THE COLLECTOR PIPE. THOSE TUBES THAT DO NOT, MUST BE MOUNTED PARALLEL OR ANGLE DOWN, IN REFERENCE TO THE CYLINDER HEAD, THEN TURN DOWN AND TURN TO THE REAR INTO THE COLLECTOR PIPE. NO STAINLESS STEEL, STEPPED OR 180-DEGREE HEADERS ALLOWED. NO SPACERS BETWEEN THE CYLINDER HEAD AND THE HEADER. POSITIVELY NO INSERTS ALLOWED IN ANY PART OF THE HEADER OR THE COLLECTOR. NO MERGE OR PYRAMID COLLECTORS. NO COATINGS OF ANY TYPE IN THE HEADERS. 3” OF THERMAL WRAP MAY BE USED TO PROTECT THE SPARK PLUG WIRES. THERMAL WRAP IS NOT ALLOWED ANYWHERE ELSE ON THE HEADERS. CHEVROLET MUST USE ONE OF THE FOLLOWING HEADERS; DYNATECK # 01-21900, HEADMAN # 68600, SCHOENFELD # 185 OR 151EL. FORD MAY USE SCHOENFIELD PART# 351 OR 551. FORD AND CHRYSLER MUST COMPLY WITH THE ABOVE RULE.

MUFFLERS: MANDATORY! SEE GENERAL RULES.

EXHAUST PIPES: MAXIMUM 3” INSIDE DIAMETER AND MINIMUM 2 ½” INSIDE DIAMETER. EXHAUST PIPES MUST FIT OVER THE COLLECTOR. PIPES MUST EXIT 6” BEHIND THE DRIVERS SEAT. BOTH PIPES MAY EXIT ON THE SAME SIDE, BUT MUST REMAIN UNDER THE CAR

IGNITION: ELECTRONIC DISTRIBUTORS MUST BE GEAR DRIVEN, USE AN EIGHT LOBE CAM WITH MAGNETIC PICK-UP, STOCK TYPE HOUSING, MOUNTED IN STOCK LOCATION. GM, FORD & CHRYSLER MUST USE A COIL IN THE CAP HEI TYPE DISTRIBUTOR WITH A GM OEM TYPE IGNITION MODULE. NO AFTER MARKET CAPACITIVE “MSD” TYPE SYSTEMS. THE FOLLOWING WILL NOT BE PERMITTED; ADJUSTABLE TIMING CONTROLS, IGNITION DELAY/TIMING RETARD DEVICES, EXTERNAL RPM LIMITERS, ANY ACCESSORIES THAT REGULATE THE POWER SUPPLY. THE FOLLOWING SYSTEMS ARE NOT PERMITTED; COMPUTERIZED, MULTI-COIL, DISTRIBUTORLESS, DUAL FIRING MODULE BOX, CRANK TRIGGERED OR MAGNETO SYSTEMS.

BATTERY: MUST BE MOUNTED INSIDE THE FRAME RAILS AND FORWARD OF THE REAR END. THE BATTERY CANNOT BE INSIDE THE DRIVERS COMPARTMENT. THE POSITIVE BATTERY CABLE MUST BE INSIDE THE FRAME RAILS.

BELTS & PULLEYS: V-BELTS ONLY. ALUMINUM AFTERMARKET PULLEYS ALLOWED.

ALTERNATOR: MUST BE MOUNTED ON THE FRONT OF THE ENGINE.

STARTER: STOCK OR AFTERMARKET ALLOWED. MUST MOUNT IN STOCK LOCATION.

WATERPUMP: STOCK OEM MECHANICAL TYPE ONLY. MUST BE V-BELT DRIVEN. ALUMINUM PUMPS ALLOWED.

FUEL PUMP: ONE MECHANICAL ONLY. MUST BE IN STOCK LOCATION.

DRIVETRAIN:

BELL HOUSING: COMMERCIALLY MANUFACTURED ALL STEEL FULLY ENCLOSED BLOW SHIELD. A 2” HOLE IS MANDATORY FOR INSPECTION OF THE CLUTCH ASSEMBLY. A 1” HOLE IS REQUIRED ABOVE THE RING GEAR TO ASSIST IN CRANKSHAFT ROTATION DURING COMPRESSION TESTING.

CLUTCH & FLYWHEEL: OEM OR EXACT REPLACEMENT MAY BE USED PER THE FOLLOWING; MINIMUM SIZE CLUTCH AND PLATE IS 10”. NO ALUMINUM, TITANIUM OR CARBON FIBER CLUTCH OR FLYWHEEL PARTS, INCLUDING FASTENERS. NO DRILLING, LIGHTENING OR ANY MODIFICATIONS. MINIMUM WEIGHTS ARE; FLYWHEEL 12.5 LBS., CLUTCH COVER 13.0 LBS., CLUTCH DISC 3.0 LBS. HYDRAULIC CLUTCH LINKAGE IS ALLOWED.

TRANSMISSION: STOCK OEM 3 OR 4 SPEED MANUAL TRANSMISSION ONLY. ALL GEARS MUST BE IN WORKING ORDER FROM INSIDE THE DRIVERS COMPARTMENT WITH MECHANICAL LINKAGE.  ALL INTERNAL PARTS MUST BE STOCK. STOCK GEAR RATIOS ONLY. NO WELDING, MACHINING, DRILLING OR LIGHTENING OF ANY PARTS. HIGH GEAR MUST HAVE A 1:1 RATIO, AND NO OTHER GEAR MAY HAVE A RATIO CLOSER THAN 1.2:1. NO OVERDRIVE OR SPECIAL PRODUCTION TRANSMISSIONS ALLOWED.

DRIVESHAFT:  STEEL ONLY.

REAREND: MUST BE A STOCK DISC OR DRUM OEM UNIT. NO INDEPENDENT REARS. STEEL ASSEMBLY ONLY. NO ALUMINUM PARTS INSIDE THE REAREND ASSEMBLY. REAREND MUST BE EITHER “OPEN” OR “LOCKED”. POSITIVELY NO POSI, LIMITED SLIP OR RATCHET REARS OF ANY TYPE. REARS MAY BE SWITCHED BETWEEN MAKES AND MODELS. AFTERMARKET SPOOLS MAY BE USED. THE CENTERLINE OF THE REAR (PINION FLANGE) MUST BE IN THE CENTERLINE OF THE CHASSIS. THE LEFT AND RIGHT BACKING PLATES OR ROTORS MUST BE OF EQUAL DISTANCE FROM THE FRAME RAILS. THE BRACKETS THAT ATTACH THE TRAILING ARMS MAY BE CHANGED OR RELOCATED. SOLID STEEL AXLES ONLY.

GEAR RULE: MINIMUM 4.68 - MAXIMUM 5.14

ADJUSTING DEVICES:

THE ONLY DEVICE IN THE DRIVERS COMPARTMENT WILL BE FOR BRAKE PROPORTIONING. NO OTHER DEVICES OF ANY KIND TO CONTROL OR ALTER THE HANDLING, WEIGHT PERCENTAGE, RIDE HEIGHT ECT. OF THE CAR WILL BE ALLOWED.

ADDITIONAL INFORMATION:

LATE MODELS MUST ALSO COMPLY WITH THOMPSON INTERNATIONAL SPEEDWAY GENERAL/SAFETY RULES.

THOMPSON INTERNATIONAL SPEEDWAY RESERVES THE RIGHT TO CONFISCATE FROM THE FEATURE WINNER ANY/OR ALL OF THE FOLLOWING ITEMS; INTAKE MANIFOLD, IGNITION MODULE, DISTRIBUTOR, TACHOMETER, ECT. THE COMPETITOR WILL RECEIVE EITHER NEW PARTS OR MONETARY COMPENSATION FOR ANY AND ALL CONFISCATED PARTS

THOMPSON INTERNATIONAL SPEEDWAY ALSO RESERVES THE RIGHT TO ISSUE A “STOCK OUT OF THE BOX” INTAKE MANIFOLD AND/OR IGNITION MODULE, PRIOR TO ANY RACING EVENT, OR DURING POST RACE INSPECTION, CONFISCATING THEIR PARTS. FAILURE TO COMPLY WILL RESULT IN THE LOSS OF ALL EARNED POINTS AND SUSPENSION.

Sources:  Russ Dowd/Thompson International Speedway PR
Posted:  November 27, 2003