2010 Hobby Stock

2010 Hobby Stock Rules

BODY & FRAME:

 

American made passenger cars only.  Minimum of 108 inch wheelbase.  Any measurement less than 107.5 inch will be considered illegal.  Any wheelbase can be no less than one inch than factory specification for frame being used.  Novas allowed.  Camaros not allowed.  All bodies must be steel factory appearing.  1981 - 1988 Performance Bodies aftermarket street stock body packages are allowed.  Early model full frame cars may use complete metric bodies.  Interchange of non-stock packages will be closely scrutinized and subject to track official approval.  Appearance will be vital.  Aluminum hoods and/or trunk lids, stock for body being used, are allowed. Complete steel bodies, with front firewall, required.  Stock firewalls must be complete, from fender to fender, top to bottom, with all holes closed with 20 ga. steel.  Floor may be cut to allow firewall clearance for headers and distributor, but cut area must be closed with 20 ga. steel and welded.    Stock floor pan must extend from front firewall to rear firewall.  Driver compartment may be enclosed with 20 ga. steel, with complete 20 ga. steel interior window level decking.  If compartment enclosed, and decking in place, rear firewall may be removed, floor pan must remain from front firewall to no less than 25 inches forward of rear axle centerline, and must fully extend from left rocker panel to right rocker panel. Driver must be on left side of drive shaft.  Driver must have an unobstructed view at all times.  B pillar must remain, but can be replaced with plastic or aluminum, in stock location.  No narrowing of frame allowed.  Frame may be altered only forward of steering gear box and in area less than 16 inches forward of rear bumper.  Fender well may be altered or removed.  No part of driver's seat shall be less than 30 inches forward of left rear axle centerline.

 

STEERING AND SUSPENSION:

Quick release steering wheels are permitted.  Quick steer boxes are permitted.  Racing type shock absorbers are allowed, but must be stock mount type, in stock OEM location.  Racing springs are allowed, but must not extend through the stock spring bucket.  Coil spring spacers are allowed. No adjustable leaf spring shackles.  No jack bolts.  After market bushings are allowed, but mono-ball types are not allowed.  Stock lower control arms are required.  Lower control arms must be in stock factory location and be stock for make and model of frame being used.  Control arm mounts may be removed for frame repair, but must be reinstalled in stock location.  Upper control arms must match IMCA type jig or sample control arm used for technical inspection, stock upper control arms may be used. Steering gear must be factory stock for make and model of frame.  All steering parts must be OEM type.

WHEELS AND TIRES:
                 Eight inch wide steel wheels mandatory.  One bead lock is allowed, on the right rear        wheel only. Tires may be siped and/or grooved.  Any brand DOT radial tire is allowed.          Allowable sizes are 225/60, 235/60, 245/60, 255/60 and 275/60, A/R KK704 or Hossier IMCA stamped G60.  Any tire designed or intended for racing other than those listed             above is not permitted.

 

WEIGHT:
            3200 LBS minimum at the end of the race with driver. If car lost any component part, or parts, during race, it will be weighed without those parts replaced.

 

ENGINE LOCATION:

            Number one cylinder spark plug must be even with, or forward of, the upper control arm   ball joint.

           

ENGINE:

            Cast iron block only.  Maximum engine size is 364 cubic inch.  Aftermarket stock appearing connecting rods and crankshafts are allowed.  Minimum crankshaft weight 51          pounds. Polishing of connecting rod beams is not allowed.  Connecting rods must be of            press fit type; no floating pins.  No 400 cid blocks allowed.  Must retain stock stroke for           engine type (i.e., 3.48 inch for GM).   Flat top or dished pistons only; four valve reliefs      per piston required.  No cam shaft gear drives allowed.  Unaltered, stock cast iron intake         manifold required.  No "marine", "bowtie" nor aluminum manifold allowed.   Oil pan          inspection bung and plug is recommended to avoid oil pan removal.

 

            FORD ENGINE:

 

            289, 302 or351 CID blocks only.  Any cast iron OEM head is allowed.  No after market   or Boss head is allowed.  Must follow same machining procedures shown below, for GM   heads.

 

HEADS:

Any open chamber cast iron OEM factory production straight plug cylinder head is permitted, with the exception of factory high performance type heads.  Most common allowable casting numbers are ..882, ..487,..993 and ..441.   No closed chamber heads allowed, such as ….461 and …465.  Valve size is limited to 1.94 inch intake and 1.50 inch exhaust for GM.   GM 305 heads are the only exception allowed, however, intake valve cannot exceed 1.84 inch diameter, and exhaust valve cannot exceed 1.50 inch diameter.  OEM or stock appearing after market rocker arms allowed.  No roller tip rocker arms or rocker arm stud girdles allowed.  After market style rocker arm lock nuts are permitted.  Push rod guide plates are permitted.   Rocker arm studs may be pinned or screw in type.  Any single valve spring, with damper, is allowed.  Heads may be flat milled; no angle milling.  No porting or polishing.  Any work done in the valve bowl area must be done with a 360 degree cut, with the valve guide as the center point.

CAMSHAFT:

Hydraulic cam and lifters only.  Roller lifters of any type are not permitted. Camshaft lobe lift not to exceed .300 with 1.5 rocker arms or .280 with 1.60 rocker arms. Maximum valve life allowed is .450” measured at the valve.

 

IGNITION:

Stock type H.E.I. type ignition. Any ignition module is allowed. Any cap mounted coil. MSD style ignition is not permitted. One 12 volt battery allowed.

EXHAUST:

            Any street or racing header allowed, except stepped tube and/or 180 degree types.  Must be chassis design type.  Collector may not extend beyond back of driver’s seat.

 

 

CARBURETOR AND FUEL:

No fuel injection.  GM must run q-jet or Holley 4412 2 bbl. Ford must run Motorcraft 4 barrel or Holley 4412 2 bbl.  No machine work allowed except choke horn may be milled off on 4412. Racing fuel is allowed but with no performance additives.

 

TRANSMISSION:

            Any OEM automatic transmission is allowed.  Transmission must be stock and have full    working torque converter.  Torque converter must be minimum of 10 inch.  No direct          drives, valved pumps or bleeder style valve bodies.  All forward and reverse gears must     be in working order for all automatics, except Powerglides, which may have either one or             both forward gears, along with neutral and reverse in working order.  Transmission   coolers are allowed, but may not be mounted exposed in driver’s compartment.

 

            Manual transmission must be OEM stock, with all gears in working order.  Minimum         10.5 inch clutch, pressure plate and full size flywheel required.  Aluminum flywheel not       permitted.  No mini clutch or direct drive permitted. 

 

            Manual transmission must have bell housing of minimum .250 inch thick steel covering      top and minimum of each side of clutch assembly (also referred to as blow-proof bell housing).

 

            No five speed transmission, six speed transmission, overdrive transmission nor overdrive   unit is permitted.  No Bert, Brinn nor internal clutch style transmission is permitted.  Ram      couplers not allowed.  No quick change transmission or transmission adapter for gear             change is allowed.

 

Car must be self starting, and have working neutral, reverse and all forward gears, as noted.

 

 

REARENDS:

            Rear-ends must be OEM for make and model of frame, with stock length upper and lower            control arms for that frame required.  Any gear ratio which can be installed with altering   of rear-end housing is allowed.  8.5 inch may replace 7.5 inch.   Axles must be locked           together at all times, with mini spool or weld.  No limited slip, Detroit locker nor full     spool allowed.

 

BRAKES:

            Minimum of three wheel brakes required.  No adjustable proportioning valve allowed.       After market brake pedal assembly is allowed, with one master cylinder permitted.  Rear          disc brakes allowed, with steel components and a single piston caliper used.

ROLL CAGE:

            All roll bar uprights must be a minimum of 1½ inch OD, .095 inch wall tubing.  Must        have minimum of three bars on driver’s side and two bars on passenger side.  It is       recommended all welding be done by a trained and competent welder.  Door bars to be of    same description tubing as uprights.   A hoop is allowed from front up rights to front of         car, on both sides.  Bumpers can be stock bumper shell covering tubing.  Bumper must             cover no less than frame horn to frame horn, front and rear of car.  One nerf bar per side   of car is permitted.  Nerf bars cannot extend forward of front edge of door panel nor    rearward of front edge of rear wheel opening.  Nerf bars cannot extend out past outer line    of tires, at any time.  No sharp edges permitted on nerf bars or bumpers.

 

SPOILERS:

Spoiler max height is 6 inches and may be attached to the trunk only.

 

SAFETY:

            All cars must have an aluminum racing seat securely attached to roll cage.  Five point        seat belt harness, with current dates, is required.  All cars must have a window net that is      used any time car is in competition.  All cares must have a battery disconnect that is in           clear view of safety personnel and is easily accessible.