2012 Late Model Rules
(Updated 5-10-12)

WEIGHT: 2350

BLOCK:
¤ Cast iron only. 362 cubic inch max

HEADS:
¤ Steel, GM 23 degree - Ford 10 degree

CRANK:
¤ Any steel crank. 

RODS:
¤ No titanium or aluminum rods.

PISTONS:
¤ Any flat top pistons and pins. Zero deck. Plus or minus .003 tolerance

VALVE:
¤ Max intake 2.055, max exhaust 1.600. Titanium permitted.

CAM: Any

INTAKE / CARBURETOR:
¤ Any one (1) four barrel permitted. GAS or E85.

IGNITION:
¤ Any point or electronic ignition. NO traction control. All boxes subject to removal for inspection.

SETBACK:
¤ 6" maximum

TIRES:
¤ Fronts - Open Rears - Hoosier D55, 1600 or American Racer 56. Rears must durometer minimum 50, anytime

BODY:
¤ Lucas body rules. All cars must have windshield bars.

WEIGHT VARIATIONS:

OTHER THAN STOCK STROKE – ADD 50LBS          DRY SUMP – ADD 50LBS

 49.5LB MINIMUM CRANKS  -  MAY DEDUCT 50LBS

 **Weight must be posted on right-side A-pillar. Failure to post correct weight will result in disqualification.

PROTEST:

One(1) Head & Bore: $400, Bottom End: $400, Complete: $600 -TRACK Retains 30% - Visual $50

Any driver who refuses to tear down will be considered illegal and be required to start at the rear of the next feature event.      Any car found illegal during qualifications will be required to start at the rear.

CRATE MOTOR Option
¤Sealed or Rebuilt 604 Crate - 2300lbs

¤ In an effort to maintain equal competition and parity among engine combinations, starting Saturday, May 12, Crate motor Late Models may run the 32X12" sideboard with an 8" spoiler OR a 12" spoiler with standard triangular side panels. You man not run the sideboard with a 12" spoiler. Either/or.

¤ Fronts - Open Rears - Hoosier D55, 1600 or American Racer 56. Rears must durometer minimum 50, anytime

Motor must use following factory spec GM parts:
1. GM Block: #10105123
2. GM Crank: #14096036 Minimum weight 54lbs. No alteration of stroke, rod, or main journal diameter.
3. GM Rods: #12495071 - Must use GM rod bolts
4. GM Cam: #10185071
5. GM Cylinder Head: #12497186
6. GM Head Bolts: #12495499
7. GM Intake Valve: #12555331
8. GM Exhaust Valve: #12551313
9. GM Push Rod: #12371041
10. GM Rocker Arm and adjuster nut: #12367345
11. GM Rocker Stud: #12371058
12. GM Lifters: #523890
13. GM Spider and Lifter alignment retainer mandatory
14. GM Intake Manifold: #12496822 (UNTOUCHED)
15. GM Balancer: 12555879

The following Repair and Rebuild parts will be allowed for Crate Option
1. Oil Pan - Champ Pans Part #CP100LTRB
2. Oil Pump - Standard Cast Iron SB High Volume Pump
3. Piston - Mahle Part #027520 - Max Overbore .030 - Must use supplied wrist pin. No other alterations other than balancing.
4. Rings - May use Hastings, TRW, Sealed Power. No gapless rings.
5. Gaskets - Any gasket. Head gaskets must be same compressed thickness as factory GM Part #12557236 gasket which is .051.
6. Valve Springs - Aftermarket valve springs and seals are allowed, but must use factory retainers and locks.
7. Bearings - May use aftermarket engine bearings. No rollerized bearings.
8. Timing Chain & Gear - Cloyes Part #GM604
9. Seal bolts not required.

Approved Machine Work for Option #2:
Rotating assembly may be balanced. Crankshaft balancing may only be done by drilling or adding weight to counter-balance. No narrowing or knife-edging of crank will be permitted. No aftermarket sleeves allowed. Minimum piston deck height .010. No angle milling. May be line honed. No polishing of the block. Excessive casting debris may be removed. No performance enhancing coatings. Surfacing of the head for repair is permitted. No angle milling. Multi-angle valve job with minimum 44 degree and maximum 46 degree for primary valve or seat angle permitted. Combustion chamber cannot exceed 58cc minimum. Intake port 210cc max. Exhaust port 82cc max. Compression Ration maximum of 10.0:1.

Option #2 Disclaimer: The 604 rebuilt Crate Option #2 is intended to allow a racer a chance to rebuild or repair the GM 604 Crate. Nothing in these rules and guidelines are designed to improve the performance of the GM 604, only give the racer a low-cost alternative to Crate Option #1. Rebuild kits are available from Motor Warehouse in Sacramento, CA by calling 1-800-367-6717, and Part #PCH350D available with, or without pistons.