Enid Speedway Park Street stock rules are effective for all races EXCEPT during the Street Stock Nationals, Winter Nationals and any Special shows during the season. This includes engine rules.
GENERAL;
A. The street stock division cars are late model, stock appearing American made passenger cars, 1960 to current models with a minimum wheel base of 108”.
B. NO commercial vehicles, sports cars, convertibles, station wagons or rear engine cars allowed.
BODY; Must be stock appearing steel or aluminum bodies.
A. A full width screen must replace windshield extending from post to post and from cowl to top. Maximum screen opening is 2” x 4”.
B. NO rear view mirrors allowed. NO transmitting or listening devices allowed in car. NO traction devices allowed.
C. Optional body rule. Stock appearing bodies with factory type roofs and fiberglass or aluminum hoods such as Five Star of Performance Bodies allowed. For after market specifications see rule book.
D. Rear spoilers may be 8” x width of car. Side panels 8” to a taper of 1” with a length 12” from base.
FRAME;
A. Frame must be stock and of same manufacturer as body and engine. GM on GM, Ford on Ford. Except Chrysler cars can run a GM frame and suspension ONLY. Suspension must remain in stock location.
B. NO cutting to off set or narrow. Frame must remain stock and same type from front bumper to center line of rear axle. Must be full width type frame.
C. The rest of the frame may be fabricated from minimum 2” x 3” x .090 rectangular tubing or 1 3/4” x .095 round tubing. The fabricated frame must be an extension of the stock frame with NO off set.
UNI BODY CARS; Unit construction cars must retain their original body dimension, including stock spring hangers. Uni body type body may be mounted on a full frame. Must adhere to above frame rule.
SUSPENSION; Suspension must remain stock. If leaf springs were on original frame, leaf springs must be used. If coil springs were used on original frame coil springs must be used. Otherwise NO MODIFICATIONS allowed, except as follows.
A. Any steel spring or sway bar may be used if mounted in stock location.
B. NO air shocks, NO coil overs, NO nitrogen filled shocks.
C. Weight jacks allowed.
D. Racing shocks and pan hard bar allowed.
E. Lower trailing arms must be stock and mounted in stock location on frame. May be adjustable up and down but inline with original mounts. A single upper trailing arm may be fabricated and mounted on the rear end housing and extended straight forward. Upper arm may be made from 1” minimum O.D. x 0.120 inch wall tubing. Maximum length is 24” center to center with heims or rubber A frame type suspension ONLY.
F. Spindles must be stock type. NO fabricated racing spindles.
G. Upper A frames OEM type or after market non adjustable OK.
H. NO swedge type heim ends on upper A arms. Modified type uppers allowed.
I. Heim and swedge type tie rods allowed.
STEERING; Stock steering box must be in original stock location. NO rigid one piece rods to steering wheel. NO center steering. Steering wheel and driver must be on left side of drive shaft hump. NO modifications of hump and no rear drivers seat allowed. Stock type steering and after market quick steer allowed.
REAREND; Any stock passenger car or ½ ton pickup rearend allowed and must be mounted in stock locations. Rearend units may be locked.
A. No aluminum center sections. NO aluminum full spools.
B. Floater type rearends are allowed but NO quick changes.
C. One drive shaft loop mandatory. 360 degree wrap around not more than six inches from the front of drive shaft.
D. Drive shaft must be painted white.
E. All cars must have a 1” inspection hole in top right side of rearend housing. If you do not have an inspection hole you will not be allowed to pull the gear or plate. YOU WILL AUTOMATICALLY BE DISQUALIFIED.
FUEL; NO alcohol. NO nitro. Pump gas ONLY. Racing fuel OK.
BRAKES; Four wheel disc brakes allowed. Front must be OEM. Rear type optional. May be adjustable from drivers position. Four wheel brakes mandatory.
ENGINE; Any V-8 cast iron automotive engine block originally produced by an American manufacturer for passenger car use. Must be same manufacturer as frame and body.
A. Engine GM in GM, etc. Pistons may be forged OEM or replacement for that block and crank.
B. NO aluminum, high nickel, SVO, Bowtie, Direct Connection, or aftermarket blocks of any kind.
C. Domed pistons NOT allowed. Flat top or stock type dished ONLY.
D. NO mismatching of blocks and cranks allowed.
E. OEM or aftermarket steel rods are allowed. NO aluminum or titanium rods.
F. Cranks must be of same manufacturer as block and heads. NO mismatching of block and cranks allowed. After market cranks are allowed but must retain stock stroke as produced +/- .014 tolerance. Cranks may be balanced but not otherwise lightened. Counter weights may not be cut down or cut off.
CAMSHAFTS; Cams and lifters must be of a flat tappet design ONLY.
A. NO Roller cams, NO roller lifters, NO mushroom cams or lifters.
B. Lifter bore may be sleeved on right side only.
C. NO automatic cam timing devices.
HEADS; Any cast iron head OK. Heads must remain in stock location. NO offsetting or moving of dowels in blocks or heads. Heads must match block manufacturer. Example, Any approved GM heads on any approved GM block, etc. NO big block heads on small block or vice versa. No Ford on GM etc.
A. NO grinding in the valve bowl area. Pocket under valves may be opened up with cutters only to a maximum of 80 degrees.
B. Maximum valve size; GM 2.05”, Ford 2.05”, Chrysler 2.08”.
C. Heads may be surfaced.
D. NO PORT OR POLISH OF ANY KIND ANYWHERE.
E. Roller rockers, guide plates, and stud girdles are optional.
F. All valves and plug holes must remain in stock location.
CARBURETOR; Any type of American manufacturer carburetor, NOT to exceed four barrels allowed.
A. NO predators, NO solenoids allowed. NO fuel injection, NO vacuum leaks allowed between top of carb and intake valves.
B. All air fuel delivery must be through carburetor.
C. NO injection type fuel delivery systems allowed.
D. NO super or turbo chargers.
E. NO water injection systems, NO pressure systems.
INTAKE MANIFOLD; Any aluminum single carburetor intake.
A. One 1” spacer may be used between carburetor and intake manifold.
B. NO welding, grinding, cutting, porting or polishing any where on intake.
C. May port intake to match heads. One inch MAXIMUM inside of intake runners to match heads.
FUEL PUMPS; Stock mount mechanical fuel pump OK. Belt drive OK in engine compartment.
FUEL; Any type gasoline allowed. CANNOT contain any oxygen bearing compounds. NO alcohol.
BATTERY; Must be securely mounted and covered with sheet rubber. Battery must be in working order and capable of starting car at all times.
IGNITION; Battery type ignition only.
A. NO magnetos, No amplifiers.
B. Aftermarket electronics are optional.
C. Ignition on/off switch must be clearly marked.
OIL PUMPS; Only pan type oil pumps allowed.
A. NO dry sump or external pumps, unless stock production.
B. Oil pan style is optional.
C. A 1” diameter inspection hole in the upper side of pan above oil line and windage tray is mandatory. You will not be allowed to pull engine or pan if you do not have an inspection hole. YOU WILL AUTOMATICALLY BE DISQUALIFIED.
WATER PUMPS; Water pumps are limited to stock mount belt driven type.
A. Fan shrouds enclosing fan required if fan is used.
RADIATORS; Only one radiator allowed and must be centered in front of engine. NO auxiliary cooling tanks allowed. Trickle type systems allowed. Electric fans optional.
HEADERS; Exhaust manifold type is optional, but must be run into a collector.
ENGINE MISCELLANEOUS; Other equipment that must remain stock OEM includes, but is not restricted to front engine cover and timing chain cover.
A. Engine may be set back no farther than center of number one spark plug even with center of front ball joint. The number one side ball joint.
TRANSMISSION; Only 3- speed, 4-speed or automatic. Brinn type racing transmissions OK.
A. NO 5 speed transmission. NO in and out boxes. NO buttons. NO cones, NO couplers.
B. Must be clutch operated (with engine running and car still in position, driver must be able to engage car in gear and move forward then backwards.).
C. Single or multiple disc clutches allowed.
D. Automatics may use hogshead, couplers, etc.
E. Transmissions must have at least one forward and reverse gear, plus a neutral position and must be able to be shifted by driver.
F. ALL CARS MUST JOIN LINE UP UNAIDED.
G. Clutch type transmissions must be equipped with an explosion proof bell housing.
BUMPERS; Must be stock automotive front and rear, NO trimming and may have maximum of one pipe 1-½” (2”OD). Hidden behind bumper or nose piece.
A. Uprights to protect radiator may be constructed inside grill shell.
B. Nerf bars are optional, but if used, recommend install inside of body. If square tubing is used, cut an cap at 45 degrees. POSITIVELY NO SHARP EDGES OR ENDS, on bumpers, nerf bars, fenders or wheels.
C. Loop on front and rear bumper for use as wrecker pick up.
WEIGHT; All cars must weigh 3000 lbs. with driver.
FUEL CELLS; See section 3, General rule 3.2.5.
A. ROLL OVER FLAP OR ROLL OVER VALVE MUST BE INSTALLED AT FUEL CELL.
WHEELS; Steel wheels only. Rims not to exceed 10” width.
A. NO bleed off valves and only one valve stem per wheel.
B. Bead lock optional on right rear only.
TIRES; McCreary, Hoosiers, or Goodyear. 26.5, 27.0 x 10.0 x 15. Asphalt take offs only. May groove or sipe tires. OPTIONAL; Hoosier 500, 10” tire may be run.
SAFETY; Fire suits, gloves and shoes mandatory and must be worn at all times during racing. All cars must be equipped with a full size 16”x 20” window net. Window nets must be in use at all times. You may use two arm restraints instead of window nets. Arm restraints must be functional and in place when driver lines up. You will be checked and if they are not in place you will not be allowed to race.
NOT ALLOWED; NO double shocks, No double radiators, No roller or mushroom cams, NO pop up pistons, NO traction devices, NO aluminum flywheels, NO electric fuel pumps, NO porting or polishing of heads or intakes, NO gold tracs, NO ratchet type rear ends.
REMEMBER IF IT DOES NOT SAY YOU CAN …THEN YOU CAN’T!
PROMOTER RESERVES THE RIGHT TO CHANGE OR CLARIFY ANY RULES TO IMPROVE COMPETITION, SAFETY OR COST.