Pure Stock

PURE STOCK     USRA MODIFIED     USRA LIMITED MODIFIED     2013 SCHEDULE

2013 PURE STOCK RULES:

CLICK HERE TO DOWNLOAD A PRINTABLE VERSION OF THE 2013 PURE STOCK RULES

The age requirement for pure stocks is 14 years of age and up.  All minors must have a notarized release of liability form signed by a legal guardian/parent. 

BODY/FRAME:
Weight limit is 3400lbs, including driver and passenger.  Cars must be street type and must retain complete steel body.

American made passenger cars only.  Metric frame, (Monte Carlo, thunderbird) cars are allowed.  Nova’s, s-10 and ford ranger pick-ups are allowed.  Only metric framed station wagons are permitted with enclosed rear compartment.  No other makes or models will be accepted.  No camaro, Cadillac, town cars, mustang or corvette.  No commercial vehicles, convertibles or sports cars.  Altering original frame wheelbase is not allowed.  Minimum wheel base is 108” per OEM specifications for stock factory production.  Allowance to 107.5 for caster adjustment will be allowed at the technical inspection pad.

Fenders may be cut for tire clearance.  Cutting width not to exceed 7” of the tire circumference.

Body sheet metal must be in place at the beginning of each race event and kept in an acceptable appearance throughout the season.

Doors must be welded or bolted shut.

All glass, fiberglass, plastic and trim must be completely removed from the car.

Driver and passenger door may be gutted for roll cage installation, but no other gutting of the car is allowed.  This includes hood, trunk and roof as well.  If hood or trunk has already been gutted angle shall be welded in to replace factory material.

Hood and trunk must be secured with hood pins at all times.  No holes allowed in hood except for hood pin holes. 

All openings in the car that could propose a safety hazard to the driver must be sealed shut at all times.

Stock OEM bumpers are required for the same make of the car.  Bumper loops are also required in front and rear to protect the radiator and fuel cell.  The tubing will not exceed  0.95 x 1 ½ OD with a maximum height of 6” tall and no wider than the frame.

ROLL CAGE:

Roll bars must be constructed of 1.5” x 0.95” steel tubing minimum.  Main roll bar and halo must be a minimum of 1” higher than the driver’s helmet.  Minimum of three (3) door bars on the driver side and a minimum of two (2) door bars on the passenger side.  FRONT LOOP IS ALLOWED TO PROTECT RADIATOR AND FRONT FRAME ARMS.  FRONT CORE SUPPORT MAY BE REMOVED AND CAN NOT BE EXTENDED PAST HOOD.  Maximum size is 1.5” O.D., .095” tubing.  All roll cage welds must be complete and pass safety inspection by tech officials.  Floor pan may be cut for cage and sub-frame connectors, but must be replaced by a minimum of 20 gauge steel.  X-bracing under the driver (frame-to-frame) is allowed.


NERF BARS:
A single nerf bar is allowed on each side of the car.  Maximum size is 1.5"X 0.95".  May be attached main cage only at the front and rear section of the nerf bar.  This means only (2) attachment points are allowed.  No open tubing allowed.  Tubing must be capped or rounded with no sharp edges.  No nerf bars are allowed outside the rear outside quarter panel area.  Nerf bars may not extend outside of tires.

ENGINE:

Compression rule is 160 PSI cranking compression.

Straight or V-6 cylinder within 11 cubic inches of factory or V-8 engine with maximum 361 cubic inch engine must remain in stock location.  Stock motor mounts are required.  May use OEM stock steel replacement motor mounts, which must bolt into stock location.  Stock cast iron OEM blocks only.  No machining in lifter valley (except for oil flow drain openings) or in lifter bores.  Engine components must be stock, or stock appearing.  No lightweight cranks allowed.  No knife edge, no bull nosing, undercut or drilling of second or third rod journal throws allowed.  No aerowing or similar (but different brand ) cranks.  Rods must be 5.7” only.  3:48” stroke only.  49 lb minimum weight for crankshaft.  No performance parts.  Only OEM replacement style pistons with (4) equal valve relief are allowed, cast only.  Flat top or dish pistons only, must be cast, no forged pistons.  No total seal rings are allowed. 

Must have 1” sight plug in oil pan between second and third pan bolt on the drivers side.

Cylinder heads must be stock for year, make and model.  (305 on 305, 350 on 350, etc.)  No closed or partially closed chambered heads, maximum 1.94 intake valves and 1.50 exhaust valve.  No Vortec heads.  No aluminum heads.  Heads may be flat milled for surfacing reasons only.  No angle milling.  Studs may be pinned. Screw in studs will also be permitted. Casting numbers must remain in heads.  No interior deburring or grinding allowed.  Ford is allowed a 1.6 exhaust valve.  Any single valve spring with dampener is allowed.  No double or triple springs allowed.  No porting, polishing, port matching or coatings of any type allowed.  No aluminum or titanium components allowed.  Full roller rocker arms and roller tip rockers are not allowed.  Poly-locks are allowed.  Stud girdles & guide plates are not allowed.

Intake must be cast iron.  No high-rise intakes, no marine intakes. No deburring or grinding allowed.  No porting or polishing of any kind.  No brezenkis. Blocking of heat risers and EGR holes allowed.  Most brand, style or size air cleaner is allowed.  No type of RAM air or forced air induction will be allowed.  Any valve cover combination allowed.

CARBURETOR:
Carburetor must be OEM style with no modifications permitted.  It must be original size and type to year, make, and model.  NO adapters or spacers.  Removal of choke flap is the only modification allowed.  Rochester 2 barrel adaptor with 1” inch maximum of thickness.  No adapter allowed on 2 barrel GM cast iron intake.  No carburetor spacers.  Holley carburetor P# 0-7448 model 2300 or holley rebuilt # 657448 will be only holley carb allowed (if using this specific part number a 200lb weight break will be allowed).  No other rebuilder will be legal.  No alterations are permitted, except choke flap can be removed.  Must use NON- adjustable carb adapter only.  Gas only.  No additives.

Holley 4412 will be optional.  See Hobby Stock rules for allowable spacer and gaskets.  4412 must pass a “go-no-go” gauge test.

CAMSHAFT:
Camshaft and lifters must be hydraulic with a maximum of 450 lift.  Lifters must be of stock OEM type.  Tech clarifications:  in order to maintain a 450 lift on your camshaft, you must not exceed a camshaft lobe of 280 degrees with 1.6 rocker arms, which will measure a 450 lift.  Also, a 450 lift cam with 1.6 rocker arms measure a 480 lift at the valve, which will be deemed illegal.  Know what your camshaft and rocker arm combination produces in order not to exceed a 450 lift measured at the valve.  The engine must hold 15” vacuum at 1000 RPM.  No 1.6 rockers.  Stock size lifters only. 

EXHAUST:

Exhaust manifolds must be stock cast iron only.  No corvette style, (2.5 port exhaust) stock manifolds.  No porting, polishing, acid treatment or coatings.  Exhaust pipes must extend past drivers compartment.

WATER PUMP:

Cast iron water pump is required.  Pulleys may be aluminum after market.  Fan must be steel and attached to water pump.  Fan spacers may be used.  An additional electric cooling fan may be used to assist cooling under yellow flag periods, but all stock fan, pulley and belt components must remain installed.

IGNITION:

Must remain and be completely stock OEM replacement parts only.  Stock HEI ignition is allowed.  No MSD modules, no MSD systems or any aftermarket or GM ignition boxes allowed.

FUEL PUMP:
Must be stock OEM style fuel pump.  Carter and Holley manual style are allowed.  Push rod activated lever style.

FUEL TANK:
Must be securely mounted in trunk of car between frame rails. All cars must have a fuel cell with maximum capacity of 22 gallons. All fuel cells must have a roll-over valve. No plastic boat tanks.

BRAKES:
Brake system must remain stock OEM to make and model.  No aftermarket components of any kind.  Stock pedal and stock OEM master cylinders required in OEM location with no extension on the push rod or the pedal assembly.  Car must have a minimum of 3 wheel brakes in working order at all times.  No proportioning valves. Rear disc brakes will be allowed for safety reasons.  Rear disc brakes are highly recommended for safety reasons.

TRANSMISSION:
OEM stock transmission.  All torque converters must be 12” with no modifications.  All forward gears must be in working order on all transmissions with a neutral and working reverse.  No over-drive transmissions.  All standard transmissions must be OEM stock with all forward gears and reverse in working order, and minimum 10.5” clutch, pressure plate, and full size stock flywheel.  Standard transmissions must have a ¼” steel plate covering the bell housing 180 degrees over the sides and top of clutch assembly or a blow proof bell-housing.  No aluminum or light weight flywheels, no 5 or 6 speed standard transmissions, no overdrives.  It must be self starting.  Transmission coolers okay, but must be out of driver’s compartment or shielded to protect the driver.

DRIVESHAFT: 
All drive shafts must be steel and painted white.  Drive shaft must have safety loop within 6” of the front U-joint.  No chain loops allowed.

REAR END:
Must be stock OEM for make, and year of car.  Any gear ratio is allowed as long as the housing doesn’t have to be altered.  Rear end must be locked.  Mini spools are ok.  No limited slip or posi-traction.

STEERING:
Must be stock OEM steering for year, make and model.  May use after market steering shaft and quick release steering wheel disconnect.  NO quick-steer of any type.

SUSPENSION:
Suspension parts must remain stock for year, make and model.  No modification to any suspension component.  No adjustable or non-adjustable spring spacers.  No racing shocks.  Bushings may be replaced with stock style OEM type only.  No bilstein, afco, pro, and qal type racing shocks.  Racing springs allowed (steel only).  Leaf springs may use lowering blocks.  Leaf springs must be made of steel only.

TIRES:
60 series dot tires only.  Must be able to have road hazard.  NO SOFTENING OF TIRES!  No recaps.  May use Hoosier stamped G60, or American Racer KK/704.

WHEELS:

Any 8” steel wheel permitted.  Wheel minimum weight is 19 lbs.  NO light weight wheels permitted.  5/8 studs and 1” lug nuts are recommended.  NO beadlocks.  Wheel spacers will be allowed.  If using wheel spacer, 5/8 studs will be mandatory. 

DRIVER/PASSENGER RESTRAINT:

Racing seats with rib supports are required.  Seats must be securely mounted to chassis, NOT FLOOR PAN, with a minimum of 4, 3/8” bolts.  5 point safety harnesses are required; S.F.I. tag must be legible and no more than 5 years old.  Straps must NOT be frayed in any way.  Connectors must lock and unlock freely.  Must be bolted to the roll cage and frame with a minimum bolt size of 1/2” bolts.  A window net is required on both sides of car while carrying a passenger.  No sprint car nets.  All helmets must be full-face, current snell 90 or newer sticker in it.  Snell sa90 and sa00 legal.  All drivers and passengers are required to wear a driving suit.  No nomex coveralls will be allowed.  Neck brace is MANDATORY for all drivers and passengers.  Driving gloves and driving shoes are recommended.

SCORING:

Numbers must be 24” high and 4” wide on both sides of car and 28” tall on the roof and positioned so it can be read from the passenger side.  Cars must be painted and numbered neatly and to be seen easily by the scorekeepers.  The number on the roof is the most important number.  Reflective vinyl is not recommended for roof application due to the poor read ability.  All numbers must be of different color than background.  When positioning the number on the roof, it should be readable from the passenger door.

PROTEST:
Protest must be made before a feature in writing by driver ONLY!!!!!  See RPR tech official. 

$75 valve cover removal and inspection or $150 head removal and inspection of which $100 to the driver and $50 to the point fund.  Rules are subjected to change at any time. Any rule infraction to be in question will be at Royal Purple Raceway’s discretion.

CLICK HERE TO DOWNLOAD A PRINTABLE VERSION OF THE 2013 PURE STOCK RULES