Pure Stock 4-Cylinder Rules - 2009

Northern Michigan Speedway, Inc.

Phone: 231-549-3040 

Updated:
April 1, 2009

              

1)  This is not a "bump & run" class, demolition derby or "enduro".  This is a beginner class and it will be run as all other classes are run at this race track.

2)  Minimum age for this class is 14 years old.  Parents or guardians of those under 18 must sign a waiver/release for the minor and bring their birth certificate.  The track owner has the final say in determining if he feels the participant is ready to try racing.

3)Cars/trucks must be 1966 or newer, American-made only, front or rear wheel driver, 4 cylinders, non turbo charged, SINGLE OVER HEAD CAM, passenger cars, station wagons, or compact trucks.  4-wheel drive trucks are allowed if on drive shaft is disconnected (front or rear).  Maximum wheel base is 108", except for station wagons.  Mini-vans are allowed.  All cars must pass inspection.

4)  ALL glass must be removed (interior & exterior).  Windshields are mandatory (safety glass).  No rear view mirrors.      All exterior trim must be removed.  All flammable material, excluding dashboard, must be removed.  Racing seat is mandatory.  Aftermarket 5-point seat belt required - must be secured to the roll cage.  Doors must be welded shut.  Hood and trunk must be secured with hood pins for easy access.  OEM latches must be removed/disabled.  All holes in floor pan and firewall must be covered.  Fenders may be trimmed (not excessively) to remove rust.  Front fenders may be cut out.  Stock appearing bumpers required and may be welded in place.  Bumper ends must be capped to prevent hooking of bumpers.  Spoilers/non-functional hood scoops are allowed.
--Passenger seat allowed - must follow same rules as for drivers' seat - must be racing seat, 5-point seat belt, window net, door plate and roll cage.  Extra steering wheel or bar recommended for passenger to hang on to.

5)  Tires Stock tires and wheels only - 60 series D.O.T. maximum; same size tires on all 4 wheels of car;  maximum 7” wide rims.  No off-set rims.  16” tires may run - max 7 ½” rims.

6)  Mufflers:  Catalytic converter may be removed.  Maximum 100Db at 100 feet.  Any good muffler is allowed, but if muffler falls off, car will be black-flagged.  Exhaust pipe 2" O.D. maximum.

7)  Steering & Suspension:  Stock only - no modifications; camber adjustments allowed on front wheels.

8)  Cooling System:  Any stock radiator allowed - must fit in stock brackets.  180-degree fan shroud required.  An overflow container mounted in engine compartment is required.  no antifreeze, only water in radiator.

9)  Fuel Cell:  All cars must use a cell type fuel tank mounted to the trunk floor with a minimum of two 1" x 1/16" straps in each direction, bolted through the floor using doubler plates or installed in a safely constructed manner between the frame rails.  Tanks must be sealed off from driver's compartment by metal plate.  No bottom draw tanks allowed.  Maximum size of thank is 8 gallons.  Cars equipped with electric fuel pumps must install a toggle type switch, clearly marked in a bright contrasting color at the base of the drivers "A" pillar.  Oil pressure switch for fuel pump mandatory - shut off or mercury switch.

10)  Roll Bars/Cage:  Minimum 4-pt roll cage is mandatory (full cage is recommended), constructed of at least 1.5" O.D., .095" side wall roll bar steel tubing.  No exhaust pipe tubing or water pipe.  It is mandatory that the roll cage be welded or bolted to 1/8" thick, 6"x6" steel plate and bolted to floor pan using doubler plate under floor pan.  Drivers door must have at least 3 roll bar-type bars welded to roll cage and covered with a minimum 18" x 24" x 1/8" thick steel plate.  Mandatory foot plates must be 10" x 30" x 1/8" thick steel.  No offset cages.  All roll cages must pass inspection.

11)  Numbers:  Must be at least 18" high, in a contrasting color to car; must have numbers on driver and passenger door.  Time keepers must be able to read numbers.

12)  Window Nets:  Window nets, with quick release mechanism, required on drivers window.

13)  Clothing:  Fire retardant racing suit (1-piece or 2-piece) is mandatory.  Helmet support (neck brace) is mandatory.  Fire retardant gloves and shoes are strongly recommended.

14)  Helmet:  Mandatory - 85 snell or better.

15)  Fire Extinguishers:  Mandatory - a charged 2-pound minimum ABC or BC rated steel fire extinguisher with gauge must be mounted in a quick release bracket within reach of the driver.

16)  Engines:  No 350 or 500 cfm holley carburetors.

        Carburetors - must be for year and make of vehicle.

        Fuel injection - must be for year and make of vehicle.      

        Throttle body/multi-port fuel injection carburetor - must be for year and make of vehicle.

        No adaptor plate allowed under carburetor

        Ford heads : Casting mark on head is 3.740”.  Stock head is 3.800”.  Max. .050 cut is allowed off head = a total of  3.750 overall head height.

17)  Weight:  

Ford Mustang & Ford trucks - 2400 lbs - track officials may add 100 lbs to equal out class

                      Front wheel drive 2000cc and over - 2500 lbs

                      Front wheel drive under 2000cc - 2200 lbs

                      Rear wheel drive - 2300 lbs

                      2500 cc - 2500 lbs 

         ***Track official has final say for weight minimums to make this class competitive***
All added weight must be bolted in passenger seat spot; if a passenger seat is installed in vehicle, added weight must be placed behind passenger seat.

***Feature winner will start the following week's feature race from the back***

YOU MAY NOT CHANGE OR MODIFY THE CAR OR PARTS IN ANY WAY!!!