2012 305 Sprint Cars
1. ENGINE: 305 cubic inches ( max.bore of 3.801)
2. BLOCK: Chevrolet 305 blocks approved casting numbers: 361979, 460776, 460777, 460778, 14010201, 14010202, 14010203, 14088551, 14093627, 14016381, 355909, 10051118, and 10051182. ALL blocks must remain stock configuration. Cylinder bores must remain stock centerlines. NO lightening of blocks other than side motor mount bosses and fuel pump mount.
3. PISTONS: Flat top pistons. NO TOLERANCE
4. CRANK:Stock iron or steel, min. weight 48 lbs. 1% tolerance, min. main bearing diameter 2.450” - .030, 3.480” stroke. Large rod journal only (2.100”) NO knife edging or drilling, undercutting or lightening of counterweights allowed. No titanium crankshaft allowed.
5. RODS:I or H-beam Style 5.7” steel rods, min. rod journal diameter 2.100” - .030. Oil pan inspection hole required to view rods. No titanium rods.
6. DRIVE:No camshaft gear or belt drives. Chain may be roller-type. Stock location water pump.
7. HUB:SFI approved damper or steel or aluminum hub.
8. CAM/TAPPETS:Flat-Tappet cam, stock diameter (.842”) Tappets or stock diameter Ford (.875) solid Tappets, No roller, mushroom, hydraulic or radius tappets.
9. OIL PUMP:Wet sump, internal pump only (no crankcase vacuum systems)
10. ROCKERS:Roller rockers allowed (NO shaft systems). 3/8” or 7/16” stock or screw-in stud-mount rockers only. Max. 1.6 ratio
11. VALVE TRAIN:NO stud girdles, rev kits, or other valve train stabilizers. Valve spring specs: Max. dia. 1.265”, min. dia. 1.200”, max wire dia. .195”, full number of coils 5. NO beehive or variable rate springs. Absolute max. valve lift” (.510” int., .535” exh.), measured at zero lash at valve retainer.
12. LIFTER BOXES:Lifter bores may be bored and bushed for .842 stock diameter Chevrolet lifters or may be bored ONLY for .875 stock diameter ford lifters.
13. VALVE SIZES:Maximum 1.940” intake size and 1.500” exhaust as delivered by world products. 11/32” stem + .015” NO TITANIUM OR HOLLOW STEM VALVES.
14. STEEL:The following must be steel only: Valves, retainers, keepers, push rods, springs, tappets, crank, rods, wrist pins, fasteners, main caps. NO titanium, composites nor ceramics in engine.
15. IGNITION SYSTEMS: Magnetos, points style only. (NO CRANK TRIGGERS) No breakerless ignitions, No programmable spark boxes. NO traction control or rev limiters. External coil OK.
16. FUEL INJECTION / CARBURETION:Carburetor or constant flow fuel injection only. No ECU’s or any other electronic driver aids. NO MORE THAN ONE (1) NOZZLE PER CYLINDER.
17. HEADS:World product head #042650 is mandatory for 2012. Must retain as delivered valve sizes. 1.940” intake and 1.5” exhaust. No grinding, polishing, welding, acid/caustic work, coating, nor any other process that alters the machined surfaces or the natural sand-cast finish. HEADS may not be angle milled. Must retain all original dimensions and configurations. The only work allowed is reseating the valves. Pilot guided cutting for seat relief allowed. Absolutely no die grinding allowed. No bowl changes. No port matching. Cylinder heads must remain as delivered.
18. COMPRESSION RATIO:10.50 to 1 is absolute maximum (10.50:1).
19. WEIGHT:Minimum 1550 lbs. including the driver, at the conclusion of the race. Any bolt on weight / ballast must be painted white and the car number must be on the weight.
20.CHASSIS: Any sprint chassis is allowed, with minimum 80-inch and maximum 95-inch wheelbase. The roll cage must be of a four-post design. Frame and body must be sprint – appearing (no dirt champ cars). No elliptical tubing used on or as part of the main frame structure. NO cockpit-adjustable chassis/suspension/traction devices are allowed.
21. BUMPERS / NERF BARS:Rear bumpers and nerf are required and must be steel (cannot contain ballast or lead). Diameter must be a minimum of one inch. Minimum .095” thickness, and must be bolted in place (no pins, cotter keys, or pop rivets).
22. TIRES:Bead-lock required on right rear. No bleeders. Right rear must be Hoosier 105/18-15 HARD or 105/16-15 MEDIUM. NO tire softeners may be used. Left rear must be a Hoosier stamped Medium. Front tires are optional. HOOSIER IS RECOMMENED!!
23. WINGS…TOP WINGS: Center foil maximum size shall be 16 square feet on the top horizontal section. It may be no wider than 60” and may extend no further than the outer edge of the rear tires being ran. Center foil must be parallel to the ground and sideboards must be vertical to the ground. No hydraulic, mechanical or electrical device may be used that will enable the driver to adjust the wing from inside the car while driving the car. Wicker bill on the top lip of the center section can be no more than one (1) inch max. Wing cannot exceed 2 ½ “drop in belly of wing not counting the wicker bill. Belly thickness may not exceed 5 ½ “. Sideboards must be no more than 10 sq. ft., including to and bottom. The lip on top and bottom shall be no more than 1 ¼ “ with the lip on the front and rear to be no more than 2”. No flaps or rudders may be attached to the sideboards. No Bi-wings.
24. FRONT WING:Center foils maximum size of 6 square feet with a maximum width of 36 inches. Center foil shall be fully sheathed in aluminum. No vent holes allowed. Maximum distance from the center foil front edge to the front edge of the front axle may not exceed 20 inches. Centerfoil top surface side to side must remain flat. Center foil must be one piece. No split or bi-wings will be allowed. Wings must be fabricated of metal alloys only. No fiberglass, carbon fiber or other similar material may be used I the basic framework of the frame or the wing. Wing must not extend beyond of front tires. Wing may not be cockpit or driver adjustable while the car is stationary or in motion. No moving parts allowed on or in foil structure. The 5” section located at the rear of the front foil must not have a belly/curl arc that is out of proportion with the rest of the front foil. As measured on a 5 inch straight edge, the belly at 1 ½ inches from the rear of the foil may not be deeper than 3/8 inch. There is zero tolerance on this 3/8 in depth. It is suggested that the wing blue print specify 11/32 inch depth, so that if any deflection or movement of the wing occurs, the depth will not exceed the 3/8 inch specification. (This 3/8 inch measurement ensures that the belly/curl arc is gradual). The belly/curl arc must span the entire length of the front foil and appear to be a gradual arc with the deepest point not further back than 12 inches from the leading edge. The belly/curl arc must start at the front foils leading edge and shall not exceed a depth of 2 inches. Top foil thickness cannot exceed 3.6 inches. 1 inch wicker bill dish or flat. Side Board Panels: Side panels may not be supported by braces whose section is not horizontal. All braces or supports shall be oriented thin edge to face the air stream. Only rectangular, round or oval metal braces not exceeding 1 inch in width may be used. No aero section side panel brace material allowed. No brace or support shall resemble a wicker bill or split wing.FRONT: Front side boards maximum 12 inches tall and 26 inches long with no more than one inch overhang from the center foil front edge to the side board front edge. Side boards may have front, back, top and bottom turnouts of no more than ½ inch. TOP: Top side boards maximum size 72 inches long and 30 inches tall. Panels must be of one piece construction. Panels must be fabricated flat so as to have no turnouts or flaps made material on the front or rear of panel and no more than 1 ¼ inches on the top or bottom.
25. NUMBERS: Numbers must be visible and neat in appearance.
26. BRAKES: Inboard and left front brakes must be used as a minimum.
27. DRIVELINE SYSTEM:All driveline systems must be properly installed reinforced and/or covered. A driveling hoop or restraint is required (no open drivelines). Center section must be centered in frame.
28. FUEL TANK:Fuel tank bladder is required. Fuel tanks must be securely fastened. Any means of mounting the tank must meet the approval of the officials. A fuel shut off valve shall be required within easy reach of the driver while sitting in the car. No electric fuel pumps.
29. FUEL:Methanol or ethanol fuel only. No additives of any kind allowed.
30. WHEELS: No carbon fiber wheels.
31. MUFFLERS: Only when required by race track.
32. FRONT AXLE: Steel only. Minimum size: 2 inches by .156; 2 ¼ inch by .120; 2 3/8 inches by .095. Safety strap on steering draglink required.
33. FLOOR PAN: Steel or aluminum only
34. CARBON FIBER: No carbon fiber parts allowed in the suspension or driveline.
35. DRIVER SEAT & FUEL/FUME DEFLECTOR: Drivers seat and butt bar are required, while the fuel/fume deflector is strongly recommended. Fuel/fume deflector should be wider than driver’s seat and extend from floor pan underneath seat to turn-up behind seat.
36. SEATBELTS:Seatbelts should have the 5 or 6 point configuration of attachment to the frame or roll cage, not over 3 years old and be in good condition. The shoulder belts should be attached about waist high behind the seat to the frame or roll cage.
37. DRIVERS EQUIPMENT:S.F.I. approved full fire suit and gloves of a flame retardant nature must be worn by competitors. Nomex underwear and socks are suggested. Driving gloves, racing shoes, neck collar and restraint required. Arm restraints are required. Head and neck restraint systems are mandatory. Drivers helmet is required & must be snell SA95 or newer. Driver must be 15 years of age by date of event.
38. CARS EQUIPMENT:No aluminum roll cages, front axels, frames, rear bumpers, or nerf bars. All roll cages must be higher than the driver’s helmet. Opening on left hand side of cockpit must be a minimum of 14 inches. There must be an inspection plug in the oil pan, either a #12AN fitting or a one inch pipe plug, or the pan may be removed for inspection. A triangular safety net is strongly suggested on the right and left side of the roll cage. Metal fasteners a suggested. A padded headrest and roll cage padding around the cranial are is encouraged.
39. BODIES:Only sprint car appearing bodies, tails and hoods will be permitted. Absolutely no side foils, rudders or panels are to extend beyond the rear cage. Frames identical to the maxim “big max” frame may be fully paneled but paneling may not extend rearward of the rear rails.