1.1 CYLINDER HEADS Aftermarket billet heads permitted. Maximum two valves per
cylinder; maximum two spark plugs per cylinder.
1.2 ENGINE Any internal-combustion reciprocating, single-camshaft, automotive-type engine permitted. Maximum 528-cid (8652,3 cm3) for screw-type supercharger equipped cars; maximum 565-cid (9258.7 cm3) for Roots-type supercharger equipped cars. Maximum bore center spacing 4.900-inches (12.45 cm). Drysump oil system permitted. OEM production-line overhead-cam engines permitted. Engine must be equipped with a properly fitting lower-engine ballistic/restraint device meeting SFI Spec 7.1 properly fitting. The lower-engine-ballistic/restraint device must be specific for the oil pan and pump configuration being used and must fit according to the requirements of SFI spec 7.1 and be used as appropriately designed for the specific application. A positive method (flange, lip etc.) must be attached to the intake manifold or engine block to retain both the front and rear manifold to block gaskets in the event the engine crankcase/lifter valley become over pressurized. The flange/lip must extend past the surface of the gasket and be contoured to closely fit the block and manifold surfaces to prevent the gasket(s) from extruding. All large (valve covers, intake manifolds, superchargers, headers, heads, blocks, etc.) and all moving engine components are restricted to aluminum, steel, iron, titanium, magnesium or other conventional alloys; carbon fiber, kevlar, ceramics, composites, beryllium or other extraordinary materials prohibited. Metal, fiberglass, or carbon fiber injector hats and/or injector scoops are permitted.
1.3 EXHAUST Double pipe insulated exhaust headers mandatory. Double tube must extend to start of bend at bottom of body.
1.4 FUEL SYSTEM Fuel cell recommended. Pressurized fuel tanks prohibited. Tanks must be vented outside of body lines to prevent fire from being drawn into tank through vent. Fuel tank vent, maximum 1-inch (2.54-cm) diameter hole in front of body to vent fuel tank outside of body only. Maximum two fuel pumps. Electronic or electrically controlled fuel system prohibited. Use of propylene oxide and/or nitrous oxide prohibited. For ease of FIA Fuel Check inspection, an inline drain valve in the idle return circuit from the barrel valve is required.
1.5 INJECTOR SCOOP Injector scoop may not extend more than 18 inches (45.7 cm) forward of the center of the forward engine cylinder, may not extend more than 12 inches (30.5 cm) behind the center of the rear engine cylinder, may not be higher than the top of the windshield, may not have more than 1 square foot (929 cm2) of opening area, and may not be more than 24-inches (61.0 cm) wide.
1.6 OIL LINES All pressurized flexible oil system lines (including gauge, data recorder, and rocker oiling lines) must use factory crimped and/or commercially available connections. All must be used for their intended application. Quick disconnect, plastic, and nylon lines are prohibited. The lines must be tested and tagged to indicate they have been tested. All of the lines must be hydrostatically tested to 300 psi (20.7 bars ) for 30 seconds with no indications of separation, weeping, leaking, etc. Competitors may test and tag their own lines. All of the lines must be routed in such a way that they are not directly in line with cylinder head gaskets at the front, rear, or side of the cylinder heads.
1.7 SUPERCHARGER Roots-type maximum size: 14-71, 19-inch (48.3 cm) case length; 11 1/4-inch (28.6 cm) case width; maximum rotor cavity diameter is 5.840-inches (14.8 cm). Helix is restricted to a maximum rotor spiral of 6.5 degrees per inch (2.6 °/cm) of rotor length. Manifold burst panel meeting SFI Spec 23.1 plus restraint system meeting SFI Spec 14.2 mandatory. Maximum supercharger overdrive limits are given under article 1.12 of Section 7 – General Regulations. Screw-type superchargers must meet SFI Spec 34.1 and be re inspected by the manufacturer every three years. Manifold burst panel meeting SFI Spec 23.1 (in addition to panel in supercharger) plus restraint system meeting SFI Spec 14.21 mandatory. Supercharger restraint straps must be covered with a fire-resistant material. Cars with supercharger/intake manifold burst panel in the rear must have a stove-pipe ducting, 4-inches (10.16 cm) minimum diameter, installed to relieve burst pressure from the burst panel(s) vicinity through the firewall and out the side window. Variable multi-speed supercharger devices prohibited. Turbochargers prohibited. See General Regulations 1.12, 1.13.
1.8 THROTTLE Throttle control must be manually operated by driver's foot: electronics, pneumatics, hydraulics or any other device may in no way affect the throttle operation. A mechanical device for controlling engine RPM during burnouts may be attached to the injector or throttle linkage but may not be driver controlled.
1.9 VALVE COVERS Cast or fabricated metal valve covers using all attachment bolt holes mandatory. Valve-cover gaskets, O-rings, etc. must be completely bonded/glued to either the valve cover or cylinder head sealing surface. Vent tube adapters on the valve covers must either be fully welded to the valve covers or incorporate a gasket or O-ring that is bonded/glued to either the adapter or the valve cover. Valve covers must be fastened to the cylinder heads with studs and nuts in lieu of bolts where possible. Spark-plug tubes that penetrate the valve covers must have a restraining device to contain the spark-plug tube in the valve cover in the event the spark plug is discharged.
1.10 VENT TUBE BREATHERS FIA accepted catch can/vent tube system mandatory. Twiston/ quick disconnect fittings between the vent tube hoses and the valve cover vent tube adapters must incorporate a secondary locking device such as a hasp pin, ball lock pin, etc. Tape is not a satisfactory primary or secondary locking device. Double clamps are required on each end of all hoses used in the vent system, including the dry-sump vents. Minimum 1 1/4-inch (31.8 mm) inside diameter hoses are required from each valve cover to the catch can inlets and/or framerails and from each framerail outlet to both catch can inlets. Minimum catch can(s) capacity is a fourquart (3.78 liter) sump when the valve cover discharges are routed through the upper framerails; otherwise an eight-quart sump (7.57 liter) capacity is required. Catch cans must have adequate internal baffling. Minimum catch can inlet and outlet/discharge configuration is two 1 1/8-inch (28.6 mm) inside diameter openings (or equivalent area). Vent tubes must be unobstructed from the interior of the valve cover to the interior of the catch can; i.e., no orifices, reduced areas, filler materials, etc. See General Regulations 1.15.