Modified Microstock Specs
MODIFIED OUTLAW MICROSTOCK SERIES RULEBOOK REV-A 1/2025
Disclaimer
This set of rules are the MOM racing series guidelines, its publisher and all contributors will not be held responsible for any injuries. Each car and its equipment will be teched prior to the start of each racing season. By building and racing any form of Microstock, the builder and driver will assume all responsibility and or liability.
Basic Rules
State regulations shall be met in any State where a race is conducted.
Minimum weight of car and driver shall be 450 LBS.
Minimum width of 37”, Maximum width of 48” measured at the cars widest point.
Minimum length of 78” Maximum length of 96” bumper to bumper.
Minimum height of 30” maximum height 42” measured from the ground up, with the car’s tires on.
Wheelbase may not be shorter than 52” or longer than 67”
All steering and brake system bolts must be cotter pined or safety wired.
All cars will be inspected at the beginning of the season, any new cars starting after the beginning of the seasons safety check will need to be safety teched before entering the racing surface.
Post-Race Technical Inspection:
The top 5 cars w/drivers will be weighed after the heat and feature.
Fuel in the top 5 cars may be tested.
The top 5 may be teched according to the MOM racing associations rule book.
The top five cars will need to be available after the feature race for tech inspection which will be done and supervised by an appointed person.
If you fail tech you will lose points for that race.
The Modified Outlaw Microstock Racing Series will appoint a technical inspector to do the post race inspection and any protested engine inspections. The job of the appointed tech inspector is not to find that a person is cheating it is to assure everyone is running legal.
All rules outlined in this rule book should be followed. The spirit and intent of the rule book is to provide clear guidelines to provide fair, safe, close racing competition and to make the Modified Microstock class affordable to run.
UNLESS THE RULES STATE THAT YOU CAN DO IT, YOU CAN`T DO IT.
Protest and Tear Down Procedures
The protest notification and cash must be given to the tech inspector within 15 minutes of the end of the feature.
The protesting party shall put up the protest fee in the amount of $300.00 cash.
If the motor in question is found to be legal, the protester's funds are used to pay for the cost to put the engine back together.
If the owner's motor is found to be illegal, the money returns to the protesting party.
The owner of the illegal motor will also be disqualified from that day's races.
Both parties are allowed to be present during the tear down.
Driver Safety Gear Requirements
All drivers must always wear the required safety gear during competition.
All driver's equipment along with their car needs to be inspected prior to their first race.
Any infractions found will have to be corrected prior to racing.
If a minor infraction is addressed, it must be corrected prior to the next race.
Fire suits: A one-piece suit is required for racing in NJ. Suit must be a SFI rated fire resistant suit. SFI rated flame-retardant gloves are also required.
Helmets: A full Face SA2015 or SA2020 helmet must be worn for competition.
Head Restraints: Head & neck restraints are required to race in NJ, as well as arm restraints unless your car is equipped with window nets.
MICROSTOCK CHASSIS SPECIFICATIONS-RULES
1. DIMENSIONS
Length measured from bumper to bumper not including the exhaust pipe.
Wheel base measured from center line of front axle to center line of rear axle.
Width measured at the widest point of the car.
Height measured from the ground to the highest point of the body.
DIMENSIONS MIN. MAX.
LENGTH 78" 96"
WHEELBASE 52" 67"
WIDTH 37" 48"
HEIGHT 30" 42"
2. MININUM WEIGHT
AFTER RACE 450 LBS (AS MEASURED ON TRACK SCALE)
Removable ballast must be safely secured to the welded chassis or other welded part of the car with bolts and cotter keys or safety wire.
3. FRAMES
All welds must be complete: top, sides and bottom.
All frames (chassis) must be made of a Minimum 16 gauge {.065) 1-inch diameter steel.
Cars must have at least two bars (0.65) minimum 1/2” diameter, positioned above and outside the driver's feet and legs. There should also be one on each side of the car parallel to the main frame rails to protect the driver’s feet and legs from a car landing on top of them.
4. ROLL OVER BARS
All welds must be complete: top, sides and bottom.
All cars must have a roll cage with side bar protection.
The main roll cage must be made of a minimum of 16 gauge (.065) 1” diameter tubular, or (.065) 1” square stock, seamless wall or welded seamed wall, steel or better quality.
Side bars must be made of a minimum of 16 gauge (.065) 1/2" diameter tubular, or (.065) square stock, seamless wall or welded seamed wall, steel or better quality. Because of the current speeds of the modified cars and to assure driver safety It is recommended that these bars be made out of 3/4” tube instead of 1/2". The size of this bar may be revisited in the future and the 3/4" size may be made mandatory.
Sidebars must be placed to prevent intrusion by another vehicle into the cockpit area. Side bars should be adequately padded for driver’s protection. (SEE IMAGE A below)
All cars must have minimum of 2 sidebars, placed on both side of the cage horizontally, vertically or diagonally. Nerf bars cannot substitute for bar protection.
It is suggested that the roof and cage openings be made as small as practical to prevent intrusion of another car into the cockpit.
4. ROLL OVER BARS (CONTINUED)
Roll cage bars must have steel gussets welded in all 4 top main joints.
All roll cages must be welded to the main chassis of the car, with gussets at all
welded structural joints as appropriate.
(Contact your technical inspector to discuss specific needs)
The roll bar must clear the driver’s helmet by a minimum of 3 inches.
The driver's helmet must be at least 3” below an imaginary straight line from the top of the roll bar to the top front of the roll cage. (SEE IMAGE B below)
Driver's head and body must be entirely enclosed within the roll-cage and body.
Any roll bar within 3” of the drivers head or torso must be padded.
5. BUMPERS
All welds must be complete: top, sides and bottom.
All cars shall be equipped with bumpers on the front and rear of the vehicle.
Bumpers must be welded or bolted securely to the frame.
All bumpers ends must be radiused or boxed to prevent hooking or catching on to
another competitor's bumper. (SEE IMAGE C below)
5. BUMPERS (continued)
Bumpers must be made of 16-gauge (.065) minimum ¾” steel, tubular or square stock or a minimum of 1" diameter (.100) wall thickness aluminum.
Channel bumpers are not permitted.
Bumpers must be 3"-5" from the ground to the bottom of the lowest bumper rail. Minimum bumper height: 6" measured between the bottom and top rails.
The rear bumper must have a minimum of 2 vertical connecting bars, spaced evenly across the bumper in addition to the mounting points.
The rear bumper must cover the full width of the vehicle to at least the center of the rear tires, but not to extend beyond the outer edge of the tires.
Front bumpers must have at least 2 vertical connecting bars in addition to the mounting points and must be between 13" and 24" wide, centered between the main frame rails where they attach to the front of the frame.
Front bumpers must be mounted at the same height as the rear bumpers. 3"-5" from the ground to the bottom of the lowest bumper rail. Minimum bumper height: 6" measured between the bottom and top rails.
6. NERF BARS
All welds must be complete: top, sides and bottom.
Must be made of Steel or aluminum.
Steel nerf bars must be made of a minimum of ¾” (.065) tubular or square stock steel and have a minimum of 1/2” .065 over rider bar welded on top of the nerf bar, or a minimum of 3/4" (.065) tubular or square stock steel or under-rider bar welded on bottom of the nerf bar. Because of the current speeds of the modified cars and to assure driver safety It is recommended that the over ride bar be made out of 3/4” tube instead of 1/2". The size of this bar may be revisited in the future and the 3/4" size may be made mandatory.
Aluminum nerf bars must be a minimum of 1" diameter (.100) tubular and have a minimum of 1” over rider bar welded on top of the nerf bar or a minimum of 1”, (.100) tubular or square stock under-rider bar welded on bottom of the nerf bar.
Nerf bar must extend within 2” of but not beyond the outside edge of the rear tires.
Nerf bar must be a minimum of half the length of the wheelbase.
Nerf bar must be welded or bolted securely to the frame. All welds must be complete: top, sides and bottom.
7. FIRE WALL
Full Rear & Side Engine Fire walls and flooring must always be complete.
All cars must have a minimum of .030" thickness metal firewall completely sealing the driver from the fuel supply and the engine compartment.
8. FLOORING
All cars must have a minimum of .030"thickness metal floor pan with no openings between the driver and ground. The floor pan must cover the full underside of the car from nose of the car to the rear end of the driver’s seat or the beginning of firewall, in order to shield driver's body from the ground.
Any large openings between the floor pan and body must have steel ½” x ½” screening or protective covering to prevent track debris from entering driver compartment.
9. FUEL LINES AND FUEL TANKS
No fuel lines or fuel tanks are allowed in the driver’s compartment. Fuel lines must be 3" from any exhaust pipe or be shielded by metal.
Tank must be of an approved type for carrying fuel.
The fuel tank may not extend outside of the car and must be protected from impact with a steel bar.
External fuel tanks must have an external fuel shut off valve and fuel lines must be clamped or safety wired.
10. EXHAUST
The exhaust outlet must be a minimum of 3" from any tire and is not included in measurements of the overall length of the car.
On rear engine cars the exhaust outlet must exit to the outside of car body or frame and may extend a maximum of 4” beyond the rear bumper.
On side engine cars the exhaust outlet must not be in an enclosed space and must extend a minimum of 3” behind the rearmost part of the firewall.
A strap (or cable) must anchor the exhaust pipe so that breakage of the normal exhaust mounting will not result in the pipe falling off the car.
The rear most end of the exhaust pipe must have a minimum 2” outside diameter. A WKA type RLV muffler is required.
11. TIRES AND WHEELS
Maximum Diameter
Wheel 6”
Tire 15”
Wheels must be of quality construction and material approved for racing competition.
No fun go-kart wheels. All cars must start the race with 4 tires, no more no less.
Wheel axles must be cotter keyed or C clipped.
Live rear only. No slipper or ratchet hubs-both rear wheels must be fixed.
12. STEERING/FRONT AXLES
Cars must have direct mechanical steering with all axle linkage bolts and nuts cotter-keyed or safety-wired. All rod ends must have aircraft quality universal-type swivel joints. Rack and pinion allowed.
Stub axles and full axles must be rigidly mounted (bolted or welded) to the chassis such that there is only UNSPRUNG weight. No SPRUNG weight allowed.
Hydraulic or pneumatic shock absorbers affecting motion of axles or stub axles are not permitted. A visual check should reveal no springs or Hydraulic or pneumatic shock absorbers are controlling the rotative axle or stub axle motion.
All cars must have a footrest or heel stop to prevent feet from sliding out the nose of the vehicle.
13. BRAKE SYSTEM
Brake system must be mechanical or hydraulic foot pedal operated disc type brake system only. All brake system bolts must be safety wired or cotter keyed
Minimum of 2 wheel braking required.
14. IGNITION KILL SWITCH
Cars must be equipped with a safety kill switch that will shut off the ignition to the motor. Switch must be accessible within driver's compartment and must be conspicuously labeled ON and OFF.
15. BODIES
All cars bodies must be fiberglass, metal or polycarbonate, enclosing a minimum of 70% of driver's area.
No completely open-back cars. Engine must be covered. Must have a Stock car appearance (Dirt Modified, Asphalt Modified or sedan body style). Rear panel must cover at least 50% of the rear of the car and be mounted behind the engine.
All cars must have an opening large enough to provide rapid exit for the driver from vehicle. Side windows must be open and at least 6.5”x 12” to provide emergency access to the cockpit.
All cars must have an enclosed roof that can be opened from both the inside and the outside.
Bodies must not have sharp edges.
Car numbers must be legible for scoring purposes and must be a minimum size as follows:
Both sides 10” High
Rear 5” High
Roof 10” High, readable from the side.
If a track scorer requests a change in your number scheme, you must comply.
No external wings allowed.
Any roll bar within 3" of the driver's head or torso must be padded.
Body panels may not be secured by Velcro they must be securely fastened to the car with hard fasteners.
16. WINDSHIELD
Entire windshield area must be covered by metal screen with a maximum spacing of steel ½ inch x ½ inch, or 1/8- inch thick clear Polycarbonate, with screening underlay.
No glass may be used on any car.
17. MIRRORS AND RADIOS
No mirrors or radios allowed in cars.
18. HEAD RESTS
All cars must have a head cushion attached to the roll cage, or to the back portion of a 1-piece seat. The cushion shall be mounted so that it is at the approximate height of the center of the driver's helmet. It must be a minimum of 4x4 (16” square) 2” thick.
19. SEATS
Seats must be attached to the frame of the vehicle, the roll-cage/frame, or to a sustainable metal plate attached to the frame using a minimum of 4 bolts. Attachment should be at the base or front of the seat, no more than 4" from the outside edge of the seat at the two most practical widely-spaced points. Two bolts shall be installed at the two practical widely spaced points at the top of the back of the seat. A metal strap at least 2 inches in width shall connect every 2 bolts on the inside of the seat, or be connected directly to the vehicle.
Seat mounting bolts must be grade 5 and a minimum 5/16 diameter.
Edges of the seat or other parts of the car which are within 2” and at a height to contact the driver's rib cage when strapped into driving position shall be REMOVED.
Edges remaining must be smoothed. It is recommended that the edges be padded.
It is further recommended that flat sides of the seats be padded with at least 1” of foam in any area that may contact a driver's rib cage.
20. SAFETY BELTS
Cars must be equipped with a 5 point double over-the-shoulder harness, 3” Lap belt and sub strap, with a single quick release. They must be in good condition and no older than TWO years as per New Jersey guidelines.
Belts must be fastened to the frame of the vehicle at both ends of lap belt and shoulder harness, and at least one end of the sub strap.
All fittings and connections on belts must be metal and bolts, if used, must be grade 5 or better.
Belts must be in good condition, as determined by M.O.M officials.
No homemade belts allowed.
"Cam-Lock" type seat releases will not be permitted.
21. OIL CATCH CAN
An oil catch can, must be mounted inside the body constructed such that oil blow-by cannot leak onto the track.
All oil blow-by from the engine breather system must be routed to an Oil Catch Can.
The oil catch can must be vented only to outside air. No connection to carburetor or exhaust system is permitted.
22. DRIVE TRAIN/CLUTCH
Centrifugal dry engine clutches only (No belt drives, torque converters, axle clutches or variable ratios allowed).
MODIFIED OUTLAW MICROSTOCK RACING SERIES
OVERHEAD VALVE BRIGGS ENGINE RULES
MODELS; WORLD FORMULA, ANIMAL AND INTEK ENGINES
UNLESS THE RULES STATE THAT YOU CAN DO IT, YOU CAN`T DO IT.
ALLOWED MODIFICATIONS:
1. HEAD AND VALVE TRAIN
A. Maybe ported and polished. No holes can be drilled in the ports.
B. Aftermarket valves are allowed except for Titanium. Max valve diameter
INTAKE 1.075 EXHAUST .950
C. Any valve spring and retainer
D. Rocker arms 1 to 1 RATIO ONLY
E. Rocker arms maybe welded for strength
F. Any make push rods
G. Rocker stud plate may be aftermarket
H. Stock cylinder head configuration only no billet heads allowed
I. Billet valve cover allowed
2. BLOCK
A. Maximum bore; 2.740
B. Head bolts may be replaced with studs
C. Billet PTO side cover allowed
D. Minor welding allowed to repair and brace the block.
3. CRANKSHAFT
A. Maximum stroke; 2.4380
B. Any make
C. Maybe ground, welded etc.
4. ROD
A. Any make connecting rod
5. PISTON
A. Any make piston
B. Any wrist pin
6. CAMSHAFT
A. Any make cam, max lift .356 measured at push rod
7. IGNITION AND FLYWHEEL
A. Any ignition
B. PVL style Animal/World formula flywheel is allowed
C. Aftermarket billet flywheel allowed, (A BILLET FLYWHEEL IS HIGHLY RECOMMENDED)
8. CARBURETOR
A. Any single carburetor
B. No supercharging, turbo charging or fuel injection
C. Pulse type fuel pump only
9. INTAKE MANIFOLD
A. Single manifold only
10. ENGINE BREATHER
A. Solid connection to oil tank
B. Multiple hoses are allowed and must empty into an oil catch tank
11. EXHAUST
A. RLV/WKA type muffler only (PN EXF4104 or EXF 4106) (Muffler must be unaltered)
B. Any exhaust pipes allowed and must be braced
12. OIL
A. Any oil allowed
B. Any non flammable lubricating oil additives allowed
C. No nitro, no flammable or power boosting additives allowed in the oil.
13. FUEL
A. Methanol only (Any World Formula or L206 class car running with the modified class may run gasoline) No power boost additives can be added to the fuel.
14. FLYWHEEL SHROUD
A. Flywheel shroud must be installed
B. No open flywheels
15. GIRDLES/3rd BEARING SUPPORTS
A. Girdles are allowed
B. Crankshaft bearing supports are allowed
MODIFIED OUTLAW MICROSTOCK RACING SERIES
OVERHEAD HONDA AND CLONE, ENGINE RULES
MODELS: GXl60, GX200, HABOR FREIGHT BLUE, BSP 195cc, DUCAR 196 CC
LIFAN 196cc
ALLOWED MODIFICATIONS:
1. HEAD AND VALVETRAIN
A. Maybe ported and polished. No holes can be drilled in the ports.
B. Aftermarket valves are allowed except for Titanium.
MAX DIA. MAX. INTAKE: 1.010 EXHAUST: .995
C. NO CC LIMIT
D. Any valve springs and retainers
E. Any make Rocker arms and push rods
F. Stock cylinder head configuration only No billet heads allowed
G. Minor welding and epoxying is allowed for pinhole repairs on the head but must not
alter air flow.
H. Billet valve covers are allowed.
2. BLOCK
A. Max bore: 2.835 +.005 for wear
B. Billet PTO side cover allowed
C. Minor welding allowed to repair and brace the block.
D. Head bolts may be replaced with studs
E. Tillotson Racing 70/72mm cylinder blocks are allowed
3. CRANKSHAFT
A. Stock crank, maybe ground, welded and polished
B. Max stroke 2.137
4. ROD
A. Any make connecting rod
5. PISTON
A. Any make piston
B. Any wrist pin
6. CAMSHAFT
A. Any make cam, max lift .356 measured at push rod
7. IGNITION AND FLYWHEEL
A. Any ignition
B. No cast flywheels are allowed.
C. Aftermarket billet flywheels are allowed, (A BILLET FLYWHEEL IS HIGHLY RECOMMENDED)
8. CARBURETOR
A. Any single carburetor
B. No supercharging, turbo charging or fuel injection
C. Pulse type fuel pump only
9. INTAKE MANIFOLD
A. Single manifold only
10. ENGINE BREATHER
A. Solid connection to oil tank
B. Multiple hoses are allowed and must empty into an oil catch tank.
11. EXHAUST
A. RLV/WKA type muffler only (PN EXF4104 or EXF 4106) (Muffler must be unaltered)
B. Any exhaust pipes allowed and must be braced
12. OIL
A. Any oil allowed
B. Any non flammable lubricating oil additives allowed
C. No nitro, no flammable or power boosting additives allowed in the oil.
13. FUEL
A. Methanol only No power boost additives can be added to the fuel.
14. FLYWHEEL SHROUD
A. Flywheel shroud must be installed
B. No open flywheels
15. GIRDLES/3rd BEARING SUPPORTS
A. Girdles are allowed
B. Crankshaft bearing supports are allowed
Flathead Modified Briggs & Stratton Engines may compete at #425 following previous Modified Outlaw Microstock rules: