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TECHNICAL RULES FOR GRAND NATIONAL SPORTSMAN
Heat races - 10 laps
B-Main(s) - 1 lap per number of cars, but not less than eight or more than 15 laps. This race will not be run with less than four (4) cars.
Feature/A-Main - 25 laps - This field will consist of 18 cars.
All lap cars will line up at the rear of all restarts.
One (1) spin in the heat or B-Main will result in disqualification from that event at flagman's discretion. A two (2)-spin rule will be in effect for the feature. Flagman's decision will be FINAL.The Safety Inspector will decide on rules with assistance from the Rules Committee and/or Board of Directors as needed. Anything not covered in these rules will be considered illegal unless otherwise approved by the Rules Committee and/or Board of Directors.
THE BOARD OF DIRECTORS HAS THE RIGHT TO INTERPRET AND EXECUTE THE FOLLOWING RULES AS THEY SEE FIT FOR THE GOOD OF THE ASSOCIATION AND RACING IN GENERAL.
IT WILL BE THE CAR OWNER AND/OR DRIVERS' RESPONSIBILITY TO READ AND FOLLOW THE RULES IN THIS BOOK. IF YOU DO NOT UNDERSTAND WHAT IS WRITTEN, PLEASE CONTACT A TRACK OFFICIAL FOR AN EXPLANATION.
1. FRAMES
A. 1978 to 1988 GM metric frames only unless run previously.
B. Frames must be X-ed, side rails must be plated where open.
C. Front cross member may be notched and plated for fuel pump clearance only.
Upper control arm hats may be trimmed for shock clearance only.D. Weight jacks or screw jacks allowed.
E. Frame rails behind rear spring pockets may be cut and fabricated.
F. No other improvements allowed except to repair rusted or damaged areas. See diagram.
2. BALAST
Weights to be bolted securely and painted white with car number and division on each weight. Loss of weight during a race will be a mechanical black flag and that car will not return for that race. No weights in driver’s compartment.
3. SUSPENSIONS AND STEERING
A. Steering wheel to be quick release style. Steering shaft must have 2 U-joints or be collapsible style. Steering quickener allowed.
B. Stock unaltered steering box, idler arm, pitman arm and center link must be used.
C.
After-market tie rods and adjuster sleeves may be used.D. Stock unaltered metric spindles and rotors, except for tie rod mounting hole and wheel bolt pattern. No after market or drop spindles. Front Coleman hubs allowed.
E. One steel unaltered shock per wheel. No externally adjustable, coil over, air, or remote reservoir shocks. No Schrader or gas refill ports. No coil over eliminators.
F. Front lower control arms and rear trailing arms must remain stock and unaltered except for reinforcement. Front upper control arm may be replaced with complete steel tubular drop in replacement, one-piece control arm of stock length (8"), plus or minus
½" of stock length. Upper and lower ball joints must be stock dimension. NO OFFSET OR BEARING TYPE (MONO BALL) ALLOWED. No aluminum components allowed.G. All A-frame, trailing arms, steering components and suspension mountings must remain stock for frame in factory frame position.
H. Stock or neoprene bushings allowed. NO OFFSET OR BEARING TYPE (MONO BALL) ALLOWED.
I. Any O.E.M. type sway bar allowed.
4. BRAKES
Four-wheel foot operated hydraulic brakes in working order. Dual master cylinder allowed. Limiting or proportioning valves okay. Unaltered GM Metric calipers only. No aluminum, after market caliper replacements.
5. WHEELS AND TIRES
A. Racing steel wheels of 8" maximum width.
Bead locks are allowed.B. 1" hex steel lug nut mandatory. Studs must pass through lug nut completely.
C. Hoosier "E-MOD RC-4" tires only.
No grooving, sipping or softening allowed.6. ROLL CAGES
A. Four point roll cage constructed of 1 3/4" X .095" wall steel round tubing.
B. One front and one rear cross brace, recommended height at 20".
C. The main hoop behind driver must be cross-braced.
D. Two passenger side and four driver side door bars, with driver side door bars plated and having two upright bars between each driver door bar.
E. Wing window bars on drivers’ side mandatory, passenger side recommended.
F. Foot protection bar
mandatory, (may be plated for added safety).G. Two front support bars must start at cross brace height at roll cage corners and extend forward to frame. Four rear support bars must extend to frame, two starting at the rear cross brace at roll cage corners and two from the top corners of the rear cage hoop
.H. Halo bar must have one cross bar running either front to back or diagonal made of 1 ¾" x .095" wall steel round tubing. See diagram.
7. DRIVER'S COMPARTMENT
A. Condition of seat belts and shoulder harness is up to the discretion of the Safety Inspector. Belts must not be frayed. Lap and shoulder belts must be approved snap-type release belts at least three (3) inches wide and securely fastened to the frame and/or roll cage. A crotch or anti-submarine belt is mandatory, and must be a minimum two (2) inches wide. The shoulder belts must be mounted level with or slightly below the driver’s shoulders. At no time should the shoulder belts wrap around the top of the driver’s shoulders and mount to the floor.
Seat belts must not be more than 3 years old than stamp date on belt.B. Window net required, large mesh type highly recommended. Net should release from top front corner with a seat belt snap and drop downward. Net must be up and fastened at all times while car is on the track.
C. All cars are required to have adequate roll bar padding and the center of the steering wheel must be padded.
D. All roll cages must provide 2" or more clearance, measured from the top of the roll cage to the top of the driver’s helmet, when the driver is seated and strapped in, with the helmet on and in a driving position.
E. Aluminum, high back racing seat is mandatory. Seat must be bolted securely with a minimum Grade 5, 3/8" minimum diameter bolts in a minimum of six (6) places
with washers. Four (4) in the bottom of the seat and two (2) in the back. No carriage bolts.F. Head and neck restraint safety devices may be used with inspectors approval.
G. Interior sheet metals to cover all openings-front, rear and side. Floor from driver to right side can be any style as long as no higher than cross brace.
H. Floor pan must be minimum 1/8" thick steel 20" wide from the back of the driver’s seat forward to the firewall.
I. No mirrors.
8. BODIES
A.
American made hard tops and sedans only.B. Production passenger car, stock or after market template/straight-up style steel or aluminum body panels for fenders, quarter panels and trunk. Plastic front fenders allowed. Door panels to be stock, sheet metal or aluminum. No door handles, locks, moldings, factory plastic or chrome accent pieces left on the stock panels. NO wedge type bodies. Body parts must be neat and well painted.
C. Factory or after market plastic nose and tail pieces okay. Rear of car, fender to fender above bumper, to be completely enclosed. Nose of car must look stock appearing and neat looking - no wedge type or late model noses.
D.
Must have hood to start race. Hood must be steel, aluminum or fiberglass and the back of the hood must be sealed down completely. No holes in hood or hood scoops. Hood pins to be used in hood and trunk. 2 1/2" nonfunctional hood scoop allowed.E. Stainless steel windshield screen
mandatory, must be no less than .063" for mesh larger than 1/2" or no less than .035" for 1/2" or smaller mesh (no larger than 1" mesh screen allowed), to cover entire opening with three upright braces top to bottom of 3/8"or larger solid steel rod. Front screen bars to be one bar in the center of the window and other two bars evenly spaced on either side of the center one.
F. Spoiler allowed on rear of trunk lid not to exceed 6" from base to tip. Rear spoiler to be 60 ½" wide at widest point, no sideboards.
G. No rear window for safety reasons.
H. Car numbers must be painted a contrasting color and numbers between 00 and 99. Numbers must be painted on both sides and roof to face grandstand. Numbers must be at least 16" high and 3" wide. Numbers of legible size must also be placed on the front and rear of the car to aid in line-ups.
I. The car at its widest point, including rub rails may not exceed 78".
J. Absolutely no air induction of any type allowed.
9. BUMPERS AND PROTECTION BARS
A. Stock bumpers may be reinforced, ends must be strapped to fenders.
B.
Must have both bumpers to race.C. Radiator protection bar may be no higher than the front of the hood or exceed 8" above the frame rail and no wider than the frame rails and may not extend beyond the front of the bumper.
D. Trunk protection bar no higher than rear of trunk lid. Protection bars to be 1 3/4" X .095 wall round tubing or smaller. Side protection bars to be no larger than 1" X 0.095 wall square tubing with the ends capped at 45-degree angle. On doors only, may run lexan rub rails no more than 6" tall and only protruding out 1" from door.
E. All cars must have a loop, hook or other provision, (in contrasting or bright color) in the centerline of the front and back, behind the bumper line for the wrecker to hook on to.
10. ENGINES
A. American made production V-8 engine blocks only. Must be production cast iron block with standard external measurements in all respects with the exception of the permissible .060 over bore maximum. No aluminum, Bowtie, Rocket, SVO, ‘X’ or ‘R’ blocks allowed. No removing of casting numbers. No grinding or lightening.
B.
O.E.M. stock production crankshafts, or after market crankshaft may be used. All cranks must weigh a minimum of 50 lbs. Must have stock stroke for the block being used. Must remain unaltered except for balancing. No knife edging allowed.C. Forged connecting rods only. Must remain stock length for the block being used (except 400 Chevy may use 5.7 rod). No H-beam, titanium or aluminum rods.
D. Any flat top or reverse dome piston may be used as long as it has the stock wrist pin height for the engine being used (except 400 Chevy). Valve relief may be cut into the piston. No portion of the piston may protrude above the top of the block.
E. Any Hydraulic or flat tappet steel camshaft with a maximum of .500 lift measured at the retainer. Stock diameter tappets only. No mushroom or roller tappets allowed. No stud girdles or rev kits. Standard timing chain only - no gear drive or belt drives will be allowed. Roller rockers or roller tipped rockers allowed. No shaft rockers.
F. Only stock, cast iron head or SR Torquer Nos. 4266B, 4267B, 4360, 4361 can be used. No Dart, Bowtie, Vortec, angle plug, SVO, W2, GT40 or fuel injection type
cylinder heads will be allowed. Only two valves and one spark plug per cylinder. No titanium parts in the valve train allowed. Intake and exhaust ports must be in the original "as cast" configuration. Any evidence of any sanding, polishing, relieving, grinding, porting, chemical treating, abrasive blasting, alteration to the original form or the addition of material to the ports or combustion chambers is strictly forbidden. No external sanding, grinding or removal of I.D. numbers or symbols. Valves must be stock production size and in stock location. Small block Chevy maximum valve size is 2.02" intake and 1.60" exhaust, measured across the face of the valve. Stock production valve spring diameter for heads used only. Screw in studs and guide plates allowed. Minor relieving for push rod clearance. No chemical or ceramic work allowed in internal areas of intake or heads.
G. Oil pump must remain in stock location. No dry sumps or external oil pumps allowed. After market oil pans and breathers are allowed. Oil cooler, if used, to be in engine compartment only.
H. Stock production cast iron intakes on engines over 365 cubic inch. Following aluminum intakes numbers allowed on 365 cubic inch or less - GM: Victor Jr 2975 or 2972 and 2101, Weiand 7546 or 7547. Ford: 2981 or 2760 and 2665 or 2750, Cleveland 7516 or 7517. AMC: 2930 or 2035. Chrysler: 2915 or2176. Edelbrock: 7101 and 7501. After market or stock intakes to remain untouched. NO Marine type intakes.
I. Stock cast iron exhaust manifolds or headers okay. No 180-degree headers or step headers. Exhaust must exit under car, behind driver and be angled down. Mufflers are mandatory and car must pass noise level test (95 decibel at 50 feet)
J. One (two or four barrel) carburetor only with maximum spacer height of 1 1/4". Two return springs mandatory. No throttle cables allowed, must be mechanical linkage. Toe strap on gas pedal required.
K. Stock cast iron or after market aluminum water pump.
L. One radiator stock brass or aluminum in front of motor. Metal
shroud to cover top 180 degrees of fan. No electric fans. Absolutely no anti-freeze in radiator. Two-quart overflow can mandatory.M. Mini-Starter allowed. No reverse mounted starter. Must be able to start car.
N. Engine must be centered between frame rails. Engine Set-Back to be measured as 33 1\2" from top steering box mounting bolt to rear of engine and 15 1\2" from steering box mounting bolt to #1 cylinder spark plug. Crankshaft centerline can be no less than 7 1/2" from bottom of front cross member.
11. ELECTRICAL AND IGNITION
A. Factory type ignition, no Multi-spark discharge or mags. Rev limiters allowed, one chip system only.
B. No traction control devices allowed.
C. 12-volt electrical system only. One 12-volt battery only, which must be located behind driver area and securely fastened.
D. On/off and start switch to be clearly marked in driver area and easily reached by driver and safety crew.
E. It is recommended to have a main battery kill switch located behind the driver.
12. TRANSMISSIONS AND DRIVE TRAIN
A. Steel blow proof bell housing only. Upper 270 degrees of bell housing must remain in tact.
B. Flywheel to be UNALTERED stock or aftermarket. Except for balancing and re-surfacing.
C. 7 ¼" minimum diameter, steel and or aluminum, single or multi disc clutch allowed. No spoke type flex plates allowed. O.E.M. or O.E.M. replacement flex plates only.
D. U.S. manufactured passenger car or light truck three or four speed unaltered manual or automatic transmission only. If automatic, must use stock torque converter.
E. Drive shaft to be steel, painted white, and have safety loop of minimum 1" x 1/8" thickness located within one foot of front U-joint.
F. Stock rear end for frame used or Ford 9" floater recommended. Any combination okay so long as parts are steel. No aluminum parts except drive plates and spools. No off set. Drive flanges to be of equal distance on both sides of frame. No independent rear end (Corvette, Jaguar). No after market limited slip or ratchet style rear ends. (Example: Gold Track, True Track or Gleason, etc.)
G. No gun drilled axles.
13. FUEL AND TANKS
A. Pump gas only, no alcohol or additives.
B. Approved fuel cell to be enclosed in 22-gauge sheet metal with 2 straps in both directions. Straps to be 1" X 1/8" steel. Fuel cell protection bar on the bottom (as low as fuel cell). Minimum of 1 1/2" X .065 wall square tubing fuel cell hoop with two or more braces to frame. (One on each side of the fuel cell.) Fuel cell to be filled from top and have approved cap. No fuel lines in driver area.
C. Stock style fuel pump in stock location. No electric or belt drive pumps.
D. No bottom draw fuel cells. Outlet must be on top.
E. The fuel cell breather or vent must have a one-way check valve to prevent spillage in case of a rollover.
14. DRIVER'S SAFETY
Seat belts must not be more than 3 years old than stamp date on belt. Snell SA 2000 full face helmet is mandatory.
General condition of the helmet and safety strap subject to safety inspector approval. All drivers must have sufficient eye protection while on the track. Goggles or shield are mandatory.Approved fire/driver suits and neck collars are mandatory. Condition of suit is subject to safety inspector approval. May be two- (2) piece. Fire retardant shoes and gloves are recommended.
In place of neck collar, an inspector approved head and neck restraint safety device may be used. See General Track Rules in the front of this book.15. IMCA STOCK CAR CROSS-OVER RULE
IMCA Stock Cars must run their rules with the exception of using Hoosier "E-MOD RC-4" tires. There is a 4-week limitation on this rule. If the car runs more than 4 weeks, it must meet either CCRA Grand National rules or run full IMCA Stock Car rules