MINI STOCK DIVISION
1. Competing Models (cars): Any four-cylinder American or foreign made production sedan. No sports cars, convertibles, high performance cars or station wagons. No fuel injection, turbo or rotary powered cars. The 1982 – 1986 Camaros with 101” wheelbase and the 151 CID engine are eligible for competition. Front wheel drive cars and specifications must be approved by the Chief Steward prior to competition. Stock mini stock bodies may be replaced with any OEM body. Use stock Ford Mustang chassis, floor pan, front and rear firewall. All bodies and mounting must be pre-approved by the Chief Steward.
2. Competing Models (trucks): Any four-cylinder 1970 and newer American or foreign made small size, non-performance type trucks. All trucks must have come standard with a non-performance four cylinder engine. No four-wheel drive pick-ups allowed. No fuel injection, turbo charged or rotary powered trucks allowed.
3. Bodies (cars): Bodies must remain completely factory stock, must have factory stock firewalls, floorboards and body panels. Front and rear factory firewall holes must be covered with sheet metal (no aluminum). The only body parts that may have inner supports removed are: hood, both doors, front inner fenders, trunk lid, rear window side panels, dash board and roof inner panels (for roll cage installation only). Stock or stock appearing steel rear fender wells mandatory (.020 minimum). Cut wheel wells to wheel lip for tire clearance only and add edge softener or doubler on rough edge to prevent tire cutting. Hood must seal at firewall. Aftermarket (rubber or neoprene) rear bumper covers allowed over stock bumper as long as they are stock appearing and have been approved by the track officials. Trunk must be sealed from driver’s compartment (no aluminum). No hood scoops or holes in the hood. Rear deck lid must be braced to be rigid if inner support panel is removed. Original grill may be removed, but expanded metal must be installed to retain stock appearance. Interior sheet metal may be put in place, but must have a 4’ x 3’ inspection door on the passenger side with either hinges or Zeus screws allowing officials to inspect the interior area without hindrance. All floor pan, firewall (front and back) must remain in place. No sharp edges on body or bumpers. Stock bumper required with no bracing allowed. Stock bumper brackets and mounts may be welded. Any track approved stock appearing composite aftermarket nosepiece or rear bumper cover will be allowed. Keep in mind the stock appearance of your race car when applying the front and rear bumper covers. Can only have one horizontal loop bar in front of radiator. If necessary, ONE radiator support bar may be installed between front two frame rails. This radiator support bar may be installed ahead of the radiator. Vertical bars may be installed between radiator support bar and horizontal loop bar for the purpose of protecting the radiator. No wings or spoilers allowed. All doors must be welded shut. Rubber body mount bushings may be removed.
4. Bodies (trucks): Bodies must remain completely factory stock except for specified alterations. Trucks must have factory stock firewalls, floorboards and body panels. The truck bed can be fabricated from sheet metal, but must be in place at all times. The only body parts that may have inner supports removed are: hood, front inner fenders, both doors, dashboard, tailgate and roof (for roll bar installation). If inner panel of tailgate is removed, box tubing must be installed to retain rigidity. Rear fender wells must remain on the truck over the rear wheels as stock appearing as possible (.020 minimum). Cut wheel wells to wheel lip for tire clearance only and add edge softener or doubler on rough edge to prevent tire cutting. Hood must seal at firewall. No hood scoops or holes in the hood. Original grill may be removed, but expanded metal must be installed to retain stock appearance. No sharp edges on body or bumpers. Stock bumper required with no bracing allowed. Stock bumper brackets and mounts may be welded. Trucks that did not come stock with a rear bumper may build a small bumper out of round tubing or pipe. Any track approved stock appearing composite aftermarket nosepiece or rear bumper cover will be allowed. Keep in mind the stock appearance of your race car when applying the front and rear bumper covers. Can only have one horizontal loop bar in front of radiator. If necessary, ONE radiator support bar may be installed between front two frame rails. This radiator support bar may be installed ahead of the radiator. Vertical bars may be installed between radiator support bar and horizontal loop bar for the purpose of protecting the radiator. No wings or spoilers allowed.
5. All glass must be removed. Steel driver safety bars must be installed in place of the windshield in front of the driver compartment.
6. Fuel cell is required. See Safety rules at the front of this book.
7. Suspension: The suspension must remain factory stock except for specified alterations. Stock rear ends only. Must have stock rear end gear make of car or truck. Any spring and spacer may be used on front end in stock location as long as no modifications are made to the spring pockets. Rubber spacers are allowed in the front springs. Stock brackets and mounts required. Teflon bushings are allowed to replace stock rubber suspension bushings. Stock sway bar mounted in stock mounts in stock location is required. It is allowable to tie each front shock/strut tower to horizontal loop bar in one place for support. McPherson strut cars may have upper strut plate slotted for caster-camber adjustments. On applicable cars, rear leaf springs may be changed. Longer U-bolts allowed for installation of steel lowering blocks (2” maximum) between leaf springs and rear end housing. Adjustable rear shackles allowed. On applicable cars, any coil spring and spacer allowed with no upper or lower pad modifications allowed other than tab welded to lower pad to hold spring in place. Only stock appearing shocks or struts that mount in stock position in stock mounts are allowed. Minimum frame height for any competing Mini Truck is six inches (6”) measured at the lowest point of the frame.
8. Chassis: Teams will be allowed to replace the front frame horns in front of the strut towers. No changes or modifications are allowed to the stock strut towers.
9. Tires: Only standard rain tread DOT tires will be allowed for competition. Maximum tread width of 8.5” (no tolerance). High performance, soft compound, directional tires will not be permitted. Tires softeners and heaters will not be allowed. Minimum durometer reading is 65 (the track durometer is the official durometer). Tires may be impounded by OSP officials and checked. Tire manufacturers markings may not be ground off tire. No grooving or siping allowed.
10.Wheels: Steel wheels only. Eight inches (8”) maximum width. Oversized wheel studs allowed for safety, but must be approved by track officials.
11.Engines must be mounted in stock position and cannot be lowered in the car or truck. Engine must be in stock mounts only. Stock mounts may be reinforced with bolts and plates, but rubber pads must remain in place. Chains are allowed from engine to frame for safety in the event of engine mount failure.
a. Engines must be original equipment only and are to be strictly stock except for specified alterations. Engines are allowed to be .060 for bore plus wear. Engine cylinder compression must be below 185 p.s.i with the engine hot (the track gauge is the official gauge). Minimum piston to deck clearance is .005. Any flat top piston is allowed. Any pressed or floating wristpin is allowed. It is illegal to drill an oil hole in the wristpin end of the connecting rod or make any alterations to the rod. Any rod bolt is allowed.
b. No internal coating and/or painting allowed.
c. Heads must be factory stock production only. No porting, polishing, machine work or other unauthorized alterations allowed. It is illegal to angle mill heads. Oil returns may not be milled wider because of excessive head surface milling. Exhaust emission parts on applicable Ford heads may be tapped and plugged to aid in exhaust gasket sealing. A maximum of three (3) angle valve jobs are permitted. When cutting the valve seat angles, no stone or grinding marks are permitted above the bottom of the valve guide. All cutting in reference to the valve job and bowl area must be centered off the centerline of the valve guide. No radius cuts permitted. Upon completion of the valve job, the bowl area under the valve seat down to the bottom of the valve guide must still be in the same configuration as far as shape and finish as it was from the manufacturer. Surfaces and/or edges where the cutter or stone has touched must not be polished or ground. No hand grinding or polishing is permitted on any part of the head. Stock valves, springs and retainers only. “Stock” valve springs means that any stock or stock replacement spring may be used but spring diameters must match specified numbers in book pertaining to that particular engine and retainers must be factory stock. Valve spring shims are legal, but may be used only to return springs to original specifications. Stock ratio rocker arms and cam followers. Hardened cam followers allowed. Stock lifters only (hydraulic lifters may not be shimmed). Valve guide liners may be used in lieu of replacement valve guides. Any hydraulic camshaft allowed. Hydraulic valve lifters must be stock or stock replacement. The “Top Line” part #B2012 is an approved stock replacement valve lifter for the Ford 2300. Valve springs must be stock or stock replacement. Springs for Ford 2300cc: Maximum Outside Spring Diameter – 1.465; Minimum Outside Spring Diameter – 1.340. The “Seal Power” valve spring part number VS1618R is an approved stock replacement valve spring for the Ford 2300.
d. Headers are allowed, but no tri-y or tri-y design headers will be allowed. Side exiting exhaust pipes must be flush with body (no sharp edges or tire poppers). No loop in exhaust system.
e. Optional equipment includes any valve cover, oil pan, electric engine fan, air filter, timing gear, timing belt or timing pulleys allowed.
f. Carburetor: The only carburetor allowed is the Holley 500 CFM Model 4412. Optional removal of choke assembly (butterflies, shaft, rod and attachment assembly). Only changing jets, power valves, needle and seat, squirters and accelerator pump cam is allowed. Carburetor adapter not to exceed one-half inch (.5’) in height and must be made of aluminum. Intake manifolds must be factory stock. “Fuel Cat” or any other fuel pressure regulating system or parts are not allowed. Float bowl high-performance “anti-slosh vent valves” are not allowed.
g. Ignition must be factory stock except that distributor spark advance diaphragm may be removed and plate may be locked down by either one screw, rivet or tack. Factory stock or stock replacement ignition boxes.
12.Transmissions must be stock type. Must have forward and reverse gears. No racing transmissions allowed.
13.Clutch and flywheel must be stock as supplied by the manufacturer. Minimum flywheel thickness is 1.100” (no tolerance).
14.Stock brake system for that make and model of car or truck is required. Must have four wheel operating brakes. Brake parts cannot be drilled or lightened.
15.Weights: All cars must weigh one pound per cc (example Ford 2300cc – 2300 pounds) after the race with the driver. All weights will be made on Oglethorpe Speedway Park scales and will be with the driver.
a. Proper engine cc must be displayed on both sides of the hood of the car. This is the cc you are claiming in the case of an engine protest or technical inspection.
b. Weights for overbore: 2300 + .030 = 2336 lbs.; 2300 + .040 = 2348 lbs.; 2300 + .060 = 2373 lbs.
16.The absence of a specific rule does not imply approval, consent or permission regarding that subject. Any questions or doubts regarding such matters should be directed to speedway officials for a clarification.
17.Any further definitions or interpretations will be made by the OSP officials only.
18.Safety regulations are listed under “Safety” at the front of this book.
1. One 4” round mirror is allowed to be mounted on the interior driver’s side door.
2. No two-way radios or electronic communications allowed.
3. All Mini Stock drivers must use a “Raceceiver”. This will allow the control tower officials to communicate with each driver. The “Raceceiver” is available for purchase from OSP.