Come See The Thunder In The Grove



 2019 Hobby Stock Rules

The rules and/or regulations set forth herein are designed to provide for the orderly conduct of racing events and to establish minimum acceptable requirements for such events. These rules shall govern the condition of all events, and by participating in these events, all participants are deemed to have complied with these rules. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND OR REGULATIONS. They are intended as a guide for the conduct of the sport and are in no way a guarantee against injury or death to a participant, spectator, or official.

The race director shall be empowered to permit reasonable and appropriate deviation from any of the specifications herein or impose any further restrictions that in his/her opinions do not alter the minimum acceptable requirements. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviation of these rules is left to the discretion of the officials. Their decision is final.

1.)FRAME: Any year model American made car or truck. That came production with leaf springs. No metric (Monte Carlo) Or front strut type cars allowed. Unibody cars must be tied together. No front wheel drive vehicles. Wheelbase must match the factory spec for that frame (1 inch tolerance). No alterations to the frame are allowed other than bracing.

2.) ROLL CAGE: All tubing shall be at least 1.5 inch OD tubing of at least .095 wall thickness. The cage shall be an "A" shaped affair with bars running from the upper right corner to the lower left corner and just the opposite on the other side, forming an "X" as viewed from front to rear. There must also be a cross bar on top of "A" and 4 bars down the side & around the top to complete the cage around the driver. Minimum three door bars, both sides, parallel to ground, and perpendicular to driver.

Minimum four uprights tied from frame to top door bar on driver side, and minimum three uprights on passenger side. Steel door plates, 18 gauge or 0.049 inch minimum thickness, that must be securely welded to outside of door bars on driver's side. Plate must cover area from top door bar to rocker panel and from rear down post to 5 inches in front of seat. Must be visible for inspection.

3.) BODY: Bodies must have a factory production appearance and may be made of sheet metal or aluminum. Any body style is acceptable as long as it is GM to GM, Ford to Ford, Dodge to Dodge. Body must match frame. Example: Leaf Camaro to leaf Camaro. Hoods & trunk lids must be pinned down. Front & rear inner fender wells may be removed. Trunk area may not be cut no further than pinion of rear end. Must have stock type floor pad rocker panel to rocker panel-third member pinion to front firewall. Must have stock firewall. Holes in firewall must be covered. Plastic nosepiece and tailpiece allowed, recommended to match body. No wedge or late model noses allowed. Ground effects OK. All glass must be removed, all window openings in body must remain open. A maximum 7 inch metal sun visor allowed across top of windshield opening. All doors must be securely fastened. No raised quarter panels. Fenders and quarter panels may be trimmed for tire clearance. Back of body must be enclosed from fender to fender. Deck height not to exceed 40�. Spoiler must not exceed 6 inches in height & only 2 end braces are allowed not to exceed 6 inches in length. Spoiler may not be wider than trunk lid. ENCLOSED INTERIORS ALLOWED PROVIDED YOU CAN CRAWL OUT THE PASSENGER SIDE. BACK PANEL OPENED UP TO LET MUD FLY OUT.

4. BUMPERS/RUB RAILS: Bumpers not covered by plastic nose or tail piece must be complete, unaltered OEM, welded or bolted to steel bumper mounts. Fabricated tubular bumpers (front and rear) are allowed as long as the front bumpers are covered by a plastic nose. All bumpers must have rounded edges. Main bumper bar must be minimum 1.50� inch O.D. (maximum 2 inch) with 0.083 inch (maximum 0.125 inch) wall thickness. Must run inner rub rail mounted flush to body. No sharp edges allowed 0n bumpers, rub rails or bolts. No bars past outside edge of body other than rub rails. ALL CARS MUST HAVE TOW LOOPS SECURELY FASTENED TO FRONT & REAR BUMPERS.

5.) INTERIOR: 3 � inch windshield bars in front of driver. All flammable material must be removed (carpet, headliner, plastics, etc...). Gauges may be removed. Aluminum high back or containment type seat only and must be bolted in. Driver seat must be in about stock position . SFI approved safety harness is mandatory. Neck brace and window net or arm restraints also mandatory. Quick release steering wheel is OK. Kill switch required within easy reach of driver and must be clearly marked "OFF" and "ON". Driver must be sealed off from track, driveline, engine and fuel cell. Dash not to extend more than 24 inches back from center of lower windshield opening. Dash must be flat, rear can be no higher than front, except for cowl in front of driver. No other interior tin or covers. Front firewall may be reworked to allow engine clearance. Must be repaired with steel of at least same thickness as OEM. Inside rear quarters panels, below window level, may be cut out. Doors may be gutted. All OEM holes in firewalls and floor must be covered with metal or aluminum. Rear firewall and speaker deck must be metal and be of OEM design for that make and model. No mirrors of any kind.

6.) FUEL CELL: Racing fuel cells are mandatory. 32 gallon maximum. Fuel cell must be securely fastened in trunk above level of OEM trunk floor, behind rear tires, with minimum two solid steel straps around entire cell, 2 inches wide and .125 inch thick. No fuel cells allowed over rear end housing.

7.) FRONT SUSPENSION: All mounts must be in stock locations. Only the following shocks are permitted:

AFCO 10 Series Steel Body Shocks or Pro Street Stock Series Shocks. All shocks must not be painted for identification purposes.

No adjustable or aluminum shocks. Racing springs are allowed. No coil over shocks. No heim end shocks.

Adjustable/Cheater weight jacks are allowed. OEM upper A ‐frame may be replaced using aftermarket upper. A‐frame (steel or aluminum cross shaft allowed),must be nonadjustable & no hiem ends bolt on spindle savers allowed.

Shocks subject to dyno test at any time at the track officials discretion.

8.) REAR SUSPENSION: AFCO 10 Series Steel Body Shocks or Pro Street Stock Series Shocks only. No hiem end shocks. Racing springs are allowed. No adjustable shocks. No coil overs. Screw type weight jacks are not allowed. All components and mounts must be steel, unaltered OEM or OEM replacement, in about OEM location and match frame. This means very close to OEM location. Rear shock mounts can be fabricated due to crash repair or previous elimination. No sliders. Shocks subject to dyno test at any time at track officials discretion. No sway bars, pan hard bars, spring spacers, extensions, chains or cables. No suspension stops of any kind allowed.

9.) REAR END: 9 inch Ford housing highly recommended. GM rear end must have axle retention. Grand National rear ends are allowed. All rear ends must be locked. No gold tracs or any other form of traction control devices allowed.

10.) BRAKES: Must have at least 3 wheel brakes. Aftermarket pedal assemblies allowed as long as brakes are not adjustable. Brake shutoff valve must be in engine compartment, no front to rear shutoff allowed. No brake bias gauges are allowed and brake lines must remain visible.

11.) WHEELS/TIRES: 10 inch maximum width steel racing wheels only. Bead lock wheels allowed on right rear only. Metal, plastic or foam mud plug/covers are allowedon all wheels. No plastic or aluminum wheels. 5/8 wheels studs mandatory. Hoosier asphalt pull off tires only. Tires must durometer at least 50 at any time. Grooving and sipping allowed. No softening or chemically treating tires. Sidewall markings must remain visible. IMCA Hoosier G60 on 8 inch wheel.

12.) WEIGHT: All cars must weight 3200lbs after race with driver. All extra weight must be bolted to frame outside of the drivers compartment and must be painted white and be clearly marked with car number

13.) BATTERY/STARTER: One 12 volt passenger car battery only, and must be securely mounted between and above frame rails, and positive terminal must be covered. Battery must be in marine type case if mounted in driver compartment. Starter must bolt in OEM location. Car must have capabilityof starting without being pushed or pulled. Car must leave initial staging area on demand, unaided, or go to rear of that race.

14.) ENGINE: Engine must be stock production factory blocks only. Roller cam blocks are allowed and must run mechanical fuel pump. No bowtie or aluminum blocks. Casting numbers must be readable by tech official. No 400 blocks Engine set back to the #1 plug even with upper ball joint. Flat top or dished pistons only. 1�inspection hole in oil pan mandatory.

No undercut counter weights on crankshaft.

Must maintain stock stroke Chevy 3.484� Ford 3.500� Mopar 3.578�

Maximum cubic inch displacement to include clearance and wear is

361 for GM, 363 Ford & 370 Mopar.

Electric cooling fan is ok. Factory stock or HEI Distributors only.

No remote coils on GM cars.

No onboard electronic devices capable of storing information allowed.

No aftermarket electronic amplifying devices allowed.

No traction control devices of any kind.

602 GM Crate Engine will be allowed. Must have GM, IMCA

Or NE Smith seals. ((Must run 2 Bl Carb.)).

16.) INTAKE: Unaltered cast iron intake or cast iron marine intake or approved unaltered aftermarket dual plane aluminum intakes allowed. No Air Gap Intakes. No porting or gasket matching or acid dipping allowed. No Brezenski intakes or heads allowed. Plenum webbing cannot be removed on any intakes. No grinding of any kind on intake. Intakes may NOT be reworked under the carb area.

17.) CARBURETOR: 4412 Holley 2 barrel or Barry Grant/Demon 2 barrel allowed. 500 CFM. Bottom throttle plate hole 1 11/16". Venture will measure 1 3/8� Must pass go no go gauge. Carb Spacer no taller than 1 � allowed. Pump, racing or aviation gas only. NO nitrous oxide allowed.

18.) HEADS: Cylinder heads must be stock OEM (Vortec OK) Or Stock Replacement (see list below). Casting numbers or engraved markings must be readable by tech official.

2.02�-1.60� valves are the largest size allowed GM & Ford

2.02�-1.625� Mopar. No titanium components allowed.

Aftermarket valve springs are OK, not to exceed 1.50 inch OD,

No "beehive" type springs. OEM or roller rockers allowed.

No angle milling of heads. 62cc minimum combustion chamber

On all heads. It is racers responsibility to check chambers.

Screw in studs OK not to exceed 7/16". Polylocks are OK.

Stud girdles OK. No porting, polishing or removal of

any casting in valve pocket area or combustion chamber.

No aluminum or angle plug heads.

Ford P heads ok, GT40 ok. Mopar magnum ok (( No Bowtie))


GM: Engine Quest:CH350C,CH350H CH350I

Renegade: 21959B, 21968B World Product: Casting #'s

043600, 043610 Summit:151124, 152123

FORD: Renegade: 21960

CHRYSLER: Engine Quest:CH318B

19. CAMSHAFT: No roller cams or lifters allowed. Hydraulic

cams only. OPTION # 1 14� vacuum @ 1000 rpm,s. Variable

duration lifters ok.

OPTION # 2 .480 lift measured at valve retainer. Example: .320 lobe lift with 1.5 ratio rocker arm = .480 lift .316 Lobe lift with 1.52 ratio rocker arm = .480 lift .300 lobe lift with 1.6 ratio rocker arm = .480 lift. Roller rocker arms must be factory marked. If any bolts etc. are fixed to prevent inspection it is drivers responsibility to remove valve covers or disqualification.

20.) HEADERS: Headers are legal.

21.) TRANSMISSION: Automatic transmissions must be stock or TCI transmissions must have working torque converter. No Direct drive with "dummy" converters. Standard transmission must be 3 or 4 speed OEM. OEM style clutch & pressure plates. Minimum weight of all components (flywheel clutch disc & pressure plate & bolts) 30 pounds. No triple disc or "mini" clutches. Aftermarket steel flywheels are OK. Direct drives & lightening of transmissions not allowed. No Bert, Brinn or Falcon transmission allowed. Must have 360 degree explosion proof bell housing. Must have clutch inspection hole. Driver must be able to put car in gear from park/neutral and move forward and reverse at anytime of inspection. Must have driveshaft loop. Driveshaft must be painted white.

22.) CLAIM/TEARDOWN: $550 cash and swap. $50 goes to Wrecker for pulling engines. Driver claiming must have raced in the Hobby Stock class the previous 2 feature events. Claimed items include: Block, rotating assembly, camshaft, heads, balancer & timing cover. Anyone wishing to make a claim must have finished the Feature on the lead lap on the night of the claim. Only top 4 cars may be claimed. To claim, you must go to the infield and hand the cash to the officials within the 5 minute protest period. If you leave the track, the claim is void. If you refuse to swap, or refuse the teardown, you lose all money won that night and all accumulated points plus a 4 week suspension. Second refusal, same applies plus a calendar year suspension. Track owner may claim ANY engine as long as claim is made within 5 minute protest period. No driver may claim more than 1 engine during the season. No driver can be claimed more than twice. Claimed engine will be marked and must be run upon return to Batesville Motor Speedway. If "marked" engine is not run upon first visit back to Batesville Motor Speedway you will not be able to run until "marked" engine is placed in car. There is a $225 teardown rule, on included are: pistons, cams, lifters, rockers, porting of heads and intake, flywheels/clutch, driveline. Driver only may protest. $25 of the money goes into the driver's point fund. Only 2 representatives from protest team & 2 from team being protested allowed in infield during teardown. Participants will act in a gentleman manor or protest or claim cancelled at officials discretion.


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