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Nov 01

4 Cylinder

COMPETING MODELS
1. 1960-2011 compact or subcompact car, pickup truck with stock wheelbase. Maximum
wheelbase of 105″ Wheelbase.

CAR BODIES
1. Stock body cars must look stock. May use after market bumper covers on stock body.
2. Aftermarket bodies allowed and may be interchanged. See Weight.
3. Aftermarket body must meet speedway template specifications.
4. All cars must be painted and lettered professionally.
5. All cars must have complete bodies, hoods, fenders, bumpers in quality condition.
6. Fenders may not be cut or altered except for tire clearance.
7. Hood must fit to windshield with no gaps. Doors must be welded or riveted.
8. Rocker panels may be fabricated but must maintain 4″ ground clearance.
9. Front windshields must be full lexan. Back window optional. Clear lexan may be installed in therear quarter windows. No side or vent windows.
10. Speedway approved window net must be installed in the driver’s side window opening.
11. Body height minimum 4 inches.
12. Rear spoiler 4″ high with width no wider than standard deck lid and be self supporting.
13. Wrecker hookup required font and rear of car.

FRAME and SUSPENSION
1. Stock front sub frame. Stock floorboard must be visible.
2. Frame must be OEM stock. No shortening or altering wheelbase.
3. Frame rails minimum 2″x 3″ x .083 wall thickness behind rear end housing allowed.
4. Chassis rails must maintain 4″ ground clearance with driver.
5. Adjustable spring cups or screw jacks allowed on front and rear.
6. OEM type steering and steering components. Heim joints allowed on steering arms.
7. Spring spacers allowed. OEM stock spindles required.
8. Lower A-frames must be OEM Stock equal length and offset front to back must be OEM.
9. Upper A-frame or Strut Plates may be fabricated for your camber and caster preferences. Lower A-Frame mounting points must be in OEM Stock Location.
10. Front sway bar must be OEM. Mounts may be fabricated in stock location. May be fabricated tubing around radiator and acid battery location in front of front wheels.
11. OEM type rear lower trailing arms required. OEM type suspension for make and model.
12. Rear suspension must be of make and model. Mounting points must be in OEM location.
13. Rear sub may be repaired with tubing from rear kick up to fuel cell in OEM position.
14. A steel firewall must separate the driver from the engine compartment and fuel cell area.

ROLL CAGE
1. A complete speedway approved roll cage.
2. Roll cage must be constructed of roll bar tubing with a minimum outside diameter of one and
half (1 ½”) inches x .083 wall thickness.
3. Roll cage must be centered on the frame. Perimeter style. Grandfather rule applies
4. Main roll cage uprights must be attached to the top of outside frame rails.
5. Full cage is required with four uprights and four top bars.
6. Roll bars may go through front and rear firewalls.
7. Minimum of three bars in driver’s and passenger’s door required.
8. Roll bars within drivers reach must be padded.

REAR END
1. Any heavy duty rear end allowed. No quick change allowed. Gear ratio optional.
2. Must be OEM, welded, or spool rear ends allowed. Limited slip must be OEM (Clutch Style) type. No Detroit Lockers or Gleason (Gear Driven) devices allowed.
3. No Cambered rear end housings. +/- .4 Grace

SPRINGS and SHOCKS
1. OEM or OEM replacement shock or struts allowed.
2. Aftermarket steel shocks or struts allowed.
3. Aftermarket Coil springs allowed.

BRAKES
1. OEM stock brakes required. All 4 wheels must work.
2. Steel disc brakes may be used on front and rear. Brake adjusters must not be in drivers reach
3. Aftermarket brake and clutch pedal allowed. Aftermarket master cylinder(s) allowed

WHEELBASE and TREADWIDTH
1. 105″ maximum.
2. Cars must not exceed the maximum allowable tread width of 63 inches.

ENGINE
1. Maximum of four cylinders. Overbore of .040 permitted. Toyoto 3TC max bore 89mm.
2. No polishing or coating inside of block. Block must be OEM production
3. OEM or Aftermarket steel connecting rods allowed. No 6″+ rods allowed
4. Only solid steel connecting rods permitted. No rotary engines allowed.
5. Piston must not extend above top of block.
6. Toyota 3tc engine are allowed a stock shape and configuration dome piston. The flat part of
the piston cannot be above the deck.
7. OEM Crankshaft with stock stroke with no less than two inch rod journals with clearance. No excessive grinding, machining, or drilling. Balancing and stress purposes only.
8. Enlarged oil pan allowed. Oil pans must have 4″ ground clearance.
9. Aftermarket pulleys allowed. Evacuation systems allowed.
10. Engine Parts must be mass produced by the factory. No “one of a kind” parts
11. A car specification and engine manual must be provided to tech official for inspection.
12. No turbo-charged engines allowed. No mix matching of parts allowed. Ex. Ford 2300 engine must run 2300 head.

HEADS
1. Stock OEM production heads only. No aftermarket heads allowed.
2. NO modifications, no porting or polishing. No grinding of any kind. Valve job permissible as
per Speedway rule. One angle, One cut below valve seat (does not include factory cut). Do not
radius or blend bottom of cut below valve seat. This cut is to narrow the seat only, not to port
the head. If you need clarification contact speedway official.
3. OEM valve size for cylinder head required. Steel valves required.
4. Reinforcement on cam boss allowed preventing fatigue.
5. Heads must be from make and model used.

CAM SHAFT
1. Hydraulic or flat tappet cam with a maximum lift of .450, at valve with valve lash as ran in
race. Adjustable cam gear allowed
2. Any car that exceeds the max lift of .450 will be allowed to run with a 100 lb penalty. No
camshaft lifting over .510 permitted.
3. Any lifting components exceeding the maximum limitations must run a 1″ restrictor plate.

INTAKE and SPACER
1. OEM stock mass produced intake. Mounting of carburetor must be facing forward.
2. No porting, polishing, or grinding will be permitted. Do not touch it.
3. One metal spacer 1″maximum thickness may be installed between intake and carburetor.
4. Spacer must have 1 or 2 holes that must be centered and cut perpendicular with the base of the
carburetor. No tapers or bevels. No other modifications will be permitted
5. A restrictor plate may be added as necessary by speedway for competition and safety.

CARBURETOR
1. Holley 2300 2bbl carburetor model #7448 350 cfm
2. Holley 2300 2bbl carburetor model #4412 500 cfm
3. Motorcraft 2bbl carburetor
See below for rework guidelines:
1. No polishing, grinding or drilling holes will be permitted in the body of the carburetor.
2. Boosters may not be altered in any manner including size, shape or height. No Bevels.
3. Venturi area must not be altered in any manner.
4. Base plate must not be altered in shape or size.
5. Stock butterflies must not be thinned or tapered. Idle holes may be drilled in butterflies. Screw
Ends may be cut even with shafts, but screw heads must remain standard.
6. Throttle shafts must remain standard and must not be cut or thinned in any manner.
7. Any attempt to pull outside air other than through the Venturi is not permitted.

AIR CLEANER
1. Air cleaner must be under hood at all times. No holes allowed in hood.
2. Dry type paper element only. Air cleaner base must be below choke horn.
3. No tubes, funnels or anything which may control the flow of air are permitted.
4. No cold air boxes or cowl induction allowed.

TRANSMISSION and FLYWHEEL ASSEMBLY
1. OEM stock three, four, five speed manual, or automatic transmissions allowed.
2. All gears must work. Floor shift conversion allowed.
3. OEM steel clutch, pressure plate, and flywheel required. Stock OEM Flywheels may not weigh less than 16 lbs (bolts included).
4. Stock OEM design single disc and pressure plate required. No carbon fiber discs allowed.
5. Drive shaft must be painted white with safety loops attached to the bottom of car.

EXHAUST
1. Headers will be permitted. Cast iron manifolds permitted.
2. All exhaust must exit to the side of car.

ENGINE LOCATION
1. Engine, transmission, and rear end must be in OEM stock location.

COOLING SYSTEM
1. Aluminum radiators permitted. Any radiator allowed.
2. All cars must have an overflow hose to the windshield or the rear of the race car.
3. Electric fans are permitted. Antifreeze is not permitted.

ELECTRICAL SYSTEM
1. OEM Electronic or point type battery fired ignition allowed.
2. Only 1 stock appearing coil permitted.
3. Only one 12-volt battery securely mounted in a leak proof battery box permitted.
4. No MSD ignition box allowed. No adjustable timing controls.
5. Starter must be in good working order.
6. Any type traction devices are not allowed.
7. All ignition systems must be acceptable to speedway officials.
8. Computer equipped cars must run stock a computer box with a stock computer chip.

FUEL and FUEL SYSTEM
1. 100% Track fuel or 100% pump gas allowed. No mixtures of any kind.
2. All fuel must pass Speedway Fuel specifications.
3. Fuel cells are recommended. Must be securely strapped down and approved by officials.
4. Fuel cells must be fitted in the floor of trunk area.
5. All cars equipped with electric fuel pumps must have a clearly marked on/off switch.
6. Fuel cell must be vented high and to the left side.
7. Fuel injection equipped cars must run 1″ restrictor plate. Restrictor plate may be increased or
decreased at anytime at the discursion of the tech officials.

WHEELS and TIRES
1. Maximum width 8″on all 4 wheels. 13″ or 14″ steel wheels required.
2. 13″ DMS “stamped” Goodyear scuffed approved. Any dot street tire must be approved by officials before race.
3. Air bleeders will not be permitted.
4. Tires used for qualifying and race must be approved by the speedway.
5. No chemical tire treatment allowed. Durometer and sniffer enforced.
6. Speedway reserves the right to limit the amount of tires purchased.
WEIGHT
1. American rear wheel drive cars
2. Each car will weigh the minimum of 1 lb. per cc with a minimum weight of 2300 pounds.
Chevrolet 151 cubic inch must weigh 2300 pounds
3. 54% left side weight percentage
4. Front wheel drive and European cars check with speedway officials for weight and engine requirements
5. Camshaft option adds 100 lbs. to total weight. See Camshaft section.
6. May gas up after race to meet weight requirements.
7. All cars will be weighed with driver in a driving position.
8. Weight of all cars must be on back of the hood for tech purposes.
9. Any car competing with dislodged or lost weight may not add it back to make weight
requirements after the race. All lead weight must be added to chassis securely.
10. Any car is subject to a P&G (engine displacement) at any time to verify weight on hood.

AMMENDMENTS
1. These rules are subject to amendments for competition when ample notice has been given by
the speedway.
2. Speedway officials may use professional judgment for any infractions for a competitive race
program.
3. Any car that does not conform to any of the above rules may be required to add
weight and/or restrictor plate to be eligible determined by the tech committee.

****ANY RULES YOU DO NOT UNDERSTAND OR YOU NEED CLARIFICATION, PLEASE CONTACT SPEEDWAY OFFICALS. Email tech@dillonmotorspeedway.com or call the Tech Man Ronnie Barfield @ 843-496-4790 or Ron Barfield @ 843-496-4792.

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