OXFORD PLAINS SPEEDWAY
Route 26, Oxford, ME 
Phone: (207) 539-8865 

2012 RULE BOOK

MINI STOCK

*NOTICE*

NO EQUIPMENT WILL BE CONSIDERED AS HAVING BEEN APPROVED BY REASON OF HAVING PASSED THROUGH INSPECTION UNOBSERVED. THE TECHNICAL DIRECTOR SHALL DETERMINE AS TO WHETHER ANY TYPE OF CONSTRUCTION, DESIGN, OR INTERPRETATION OF ANY RULE SHALL BE ACCEPTED.

OXFORD PLAINS SPEEDWAY RESERVES THE RIGHT TO UP-DATE, MODIFY, ADD, OR DELETE RULES AT ANY TIME IN THE INTEREST OF PROVIDING PARITY FOR ALL COMPETITORS. ADDITIONAL REQUIREMENTS MAY BE MADE VIA OFFICIAL ENTRY REGISTRATION, TECHNICAL BULLETIN, OR MEETING ANNOUNCEMENT, WHICH AUTOMATICALLY AMENDS SPECIFICATIONS HEREIN.

6-1 COMPETING MODELS AS SELECTED BY OPS

6-1.1 Mini Stock Races

Oxford Mini Stock races are open to eligible models of American or Foreign standard passenger car production cars.

6-1.2 Eligible Models approved for Competition

Any hardtop, sedan, of lift-back from 1975 to 1994 with a wheel base of 87 inches to 103 inches inclusive. No Sports Car, rear or mid-mount engine models, 4-Wheel drive, or 1977 and 1978 Chevrolet Cosworth Vega models permitted. Two door Pontiac Grand Am permitted.

All other models must be approved for competition by the Oxford Plains Speedway Technical Director.

6-2 GENERAL CAR BODY REQUIREMENTS

6-2.1 Car Bodies

(a)Cars must be neat appearing. Exterior panels must remain as manufactured, except for roll bar, tire and wheel installation.

(b) Original dimensions of all bodies must remain as manufactured.

(c) All cars must have complete steel bodies, stock to all measurements. Minimum 20 gauge body panel. Roof must remain factory.

(d) Full windshield must be used. Lexan type replacement may be used. Lexan type rear window may be used. Rear quarter panel windows may be covered with Lexan type material. No tinted windows permitted.

(e) Bodies may be from 1975 to present year with a matching wheel base of + or – 2".  Technical director will have the final determination as to body eligibility.

(f) Rear spoiler permitted. Must be mounted and centered on the rear edge of the rear deck lid. Maximum surface dimensions of 54 inches wide and 4 inches in height. No side boxing permitted.  Top of spoiler no more than 5” higher than the base of the rear window.

6-2.2 Overall Car Weight

All cars must weigh according to the following schedule with a 55% left side weight with driver, gas, oil and water and being race ready:
One pound per C.C. Minimum weight 2150 lbs.

Any added weight must be securely mounted with a minimum of 3/8 inch BOLTS to the frame side rails. In order to maintain parity, weights may be adjusted as deemed necessary by OPS.

6-3 DETAILED CAR BODY REQUIREMENTS

6-3.1 Seat

It is recommended that the seat be specifically designed for auto racing and constructed of .125 inch thick aluminum. NO fiberglass seats permitted. Aircraft quality hardware is required for attaching seat to seat sub-structure in an approved manner. See diagram section for recommendations.

6-3.1.1 Seat Location

Seat must be installed in the stock location.

6-3.2 Floor Boards

Full stock floor boards in the stock location must be used. Holes must be covered with metal. NO aluminum permitted. Crush panels may be used in trunk. Maximum crush panel width is 6 (six) inches. Strut towers must be stock in stock location.

6-3.3 Front Fire Wall

Must be in original position. Holes to engine compartment must be covered with sheet metal. Firewall must be steel.  Firewall must be in stock location and remain attached to stock floorboard.  No aluminum or plastic permitted.

6-3.4 Rear Fire Wall

Must cover the entire fuel cell area so the fuel cell area is completely separated from the driver’s compartment. Firewall must be steel. No aluminum permitted.

6-3.5 Hood and Truck Lids

Stock hood and trunk lids must have inner reinforcements removed. Must use positive pull-pin type fasteners.  Must be steel.  No aluminum or fiberglass allowed.

6-3.5 Inner Panels

Inner panels may be removed, but the front half of the rear fender well must remain attached to the rear fire wall in the stock location. Wheel openings may be trimmed up to 2 (two) inches from the tire size for clearance. All wheel opening edges must be finished to eliminate sharp edges. Strut towers must be stock in stock location.

6-3.6 Bumpers

Stock front and rear bumpers must be finished on ends so that there are no sharp edges. No truck bumpers or crash guards permitted. Bumpers must be mounted in stock position. Aftermarket nosepieces may be used and be approved by the tech director.

6-3.7 Rub Rails

Rub rails may not extend beyond the outer surface of the tires.

6-4 GENERAL ENGINE REQUIREMENTS

Only four cylinder engines, stock for make will be allowed. Maximum engine CC is 2.5 liters. No V-4 or air cooled engines permitted. No rotary valve engines permitted. No 16 valve heads permitted.

6-5 DETAILED ENGINE REQUIREMENTS

6-5.1 Engine Location

Stock for make

6-5.2 Engine Block

Stock for make

6-5.3 Engine Overbore

Maximum overbore permitted is .040

6-5.4 Piston / Rods

Stock for make and model. Aftermarket or performance replacement may be use but must be the same in all aspects including weight.

6-5.5 Oil Pan

Stock OEM only. A stock bolt in windage tray may be used.

6-5.6 Cylinder Heads

Stock for make and model engine used. No porting, polishing, painting, or relieving of cylinder head permitted. Head planing is allowed. 11.499 absolute maximum compression ratio.

6-5.7 Valves

Stock valves only. No reworking of valve area permitted.

6-5.8 Camshaft / Valve Lifters / Rocker Arms

6-5.8.1 Camshaft

Any flat tappet cam shaft permitted. Maximum gross valve lift is .450 measured at the valve.

6-5.8.2 Valve Lifters

Stock for make and model. No roller lifters.

6-5.8.3 Rocker Arms

Stock for make and model. No roller rockers.

6-5.9 Intake Manifold

Stock manufacturer’s intake manifold required.

6-5.10 Carburetor

A stock Holley Webber 5200 or stock Holley 350 cfm carburator will be allowed. Oxford Plains Speedway reserves the right to mandate type and model of carburetor permitted. No reworking of carburetor of any kind permitted. Stock factory fuel injection permitted (this change in policy will be reviewed throughout the 2012 season and changes may be made at the discretion of OPS).

6-5.11 Crankshaft

OEM crankshaft must be used. No lightening or knife edging of crankshaft permitted.

6-6 ENGINE / CAR ELECTRICAL SYSTEM

6-6.1 Ignition System

Any stock ignition system may be used. No magneto systems permitted. No after market performance systems permitted.

6-6.2 Starter

Stock starter in stock location must be in working order.

6-6.3 Battery

Battery must be securely mounted and covered. No battery may be located in the trunk area.

6-6.4 Electrical Safety Switch

Car shall be equipped with a safety switch that will effectively kill the power from the battery to the car’s ignition system. Switch must be mounted with rear of the driver’s side window opening.

6-7 ENGINE COOLING SYSTEM

Any stock appearing radiator permitted. Must be in standard position inside of body work. There must be a minimum 1 (one) quart overflow tank located in the engine compartment. No antifreeze permitted.

6-8 ENGINE EXHAUST SYSTEM

Economy header will be allowed. It must have a retail value of no more than $200.00 Tech dept. will determine if a header is within the intent of this rule.

6-9 DRIVE TRAIN

6-9.1 Clutch

OEM clutch and pressure plate assembly only.

6-9.2 Flywheel

Stock flywheel only. No alterations permitted. No aluminum flywheels.

6-9.3 Transmission

Stock for make and model year used. No locked or posi-traction final drive assemblies allowed. Floor kit shift linkage may be used. All gears must be in working order. Automatic transmission allowed.

A:  Rear ends stock for year no locked or limited slip.  Open rear ends only.

6-9.4 Wheels

Stock 13 inch steel or aftermarket 13 inch steel racing wheel permitted. Maximum width measured between the bead will be 7 (seven) inches. No alloy or aluminum wheels permitted. OPS reserves the right to designate a wheel manufacturer. Minimum offset measured from the back of the wheel is 1 (one) inch.

6-9.5 Tires

Oxford Plains Speedway reserves the right to designate a tire by design and manufacturer as the only tire permitted. Refer to Rule 1-38 for the Oxford Plains Speedway tire policy.

6-9.6 Tread Width

Maximum Allowable treadwidth will be 70” from outside to outside of wheel bead..  Dodge may run spacers for rotor clearance only.  Cars not able to achieve maximum treadwidth may use a maximum ½” wheel spacer per wheel.  Spacers must be equal from side to side.  Spacers must be 1 piece only.

6-10 SUSPENSION

6-10.1 Front and Rear Suspension Components

NO SPECIALTY OR PERFORMANCE CAR SUSPENSION PARTS MAY BE USED. Stock tread width must be maintained. Stock front and rear suspension components for make and model used. Aftermarket "Original Equipment" stock replacement parts may be used. Any rebuilding of suspension and/or frame mounting systems must be same as original design in length of travel, height, and location. Any rebuilding must be approved for competition by the Technical Director.

6-10.2 Springs

Aftermarket racing springs may be used min diameter 4".Cutting and heating of front and rear springs permitted. No adjustable spring hangers permitted. Spring boosters may be used. Equal size lowering block may be used on rear suspension.

6-10.3 Wheel Camber

Front wheel camber restricted to 2 (two) inches. ¼ inch camber on right rear. No camber permitted on left rear. Independent rear suspension must have identical camber on both sides.

6.10.4 Ground Clearance

All measurements will be taken with the driver in the car. Minimum allowable ground clearance measured from the floor pan next to the frame or unibody to the ground plane is 5 (five) inches.

6-11 BRAKES

Four wheel brakes in good working order are mandatory.

6-12 FUEL / FUEL SYSTEM

Only Oxford Plains Speedway approved fuel may be used.

6-12.1 Fuel Cell

Cell must be enclosed in a 20 gauge metal canister. Fuel cell must be mounted in the trunk area and must have a minimum of 6 (six) inches of ground clearance from the lowest point to the ground plane. A safety loop at the rear of the cell to protect it from rear impact is recommended. It is recommended that a shut off valve be installed on the fuel line in the trunk area.

6-12.2 Fuel Pump

Oil pressure switch required for electric fuel pump.

6-13 GENERAL SPECIFICATIONS

6-13.1 Roll Bars

A four point roll cage made of round steel DOM or seamless 1-3/4 inch .095 wall thickness roll bars are mandatory. The roll cage shall consist of 4 (four) vertical upright bars connected at the top on all sides. A "X" member must support the rear vertical uprights. 3 (three) horizontal bars are required on the left side door area and 2 (two) on the right side. (These are minimum numbers). A bar at dash height across the front uprights is recommended. A "Front Hoop" may be used. Bars may be mounted to the rear edge of the top halo and extend to a point forward of the center line of the rear end. On uni-body a plate or other approved method must be used to mount to the cage to the body. Roll cage must run the full width of the frame, rocker panel to rocker panel.

Rollcage material is subject to sonic testing or inspection hole testing for compliance with the rules. A tester for analysis of Rollcage strength may be used repeatedly.

Driver door must have a plate with minimum of 16 gauge metal between door bars and body on driver’s side only. 16 gauge metal may be welded in between door bars and door bar connectors on driver’s side only.

6-13.2 Fire Extinguisher

A working fire extinguisher must be within reach of the driver and mounted on the right side of the car.

6-13.3 Part Identification Numbers

Any parts that have any identification numbers and those numbers are removed or altered will be declared non-conforming.

6-13.4 Non-Conforming Parts Penalty

Any parts that are found to not conform with the rules contained herein will become the property of Oxford Plains Speedway and must be surrendered immediately upon demand. Parts will be held by Oxford Plains Speedway and will be disposed of at the desire of Oxford Plains Speedway. If any team refuses to turn over any requested part or parts then that team will be denied access to Oxford Plains Speedway until such parts have been surrendered to the satisfaction of Oxford Plains Speedway management. An additional fine may be imposed as part of the penalty.

6-13.5 Declaration of Intent

Anything not specifically covered in this rule book must be approved for competition by the Technical Director.

6-14.6 Eligibility

A competitor who competes in 5 (five) or less features in a given division in a given year will be eligible for future rookie status.

IT IS THE RESPONSIBILITY OF THE COMPETITOR TO OBTAIN AND BECOME FAMILIAR WITH THE CURRENT RULES PERTAINING TO THE DIVISION IN WHICH HE/SHE CHOOSES TO PARTICIPATE.

The rules and/or regulations set forth herein are designed to provide for the orderly conduct of racing to establish minimum acceptable requirements for such events. These rules shall govern the conditions for all events, and by participating in these events all participants are deemed to have obtained and read, and understood a copy of the current rules, and complied with these rules.