B-Modified Rules
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CENTRAL
MISSOURI SPEEDWAY
2010
B-MODIFIED
RULES
The
spirit and intent of these rules is to keep down the cost of racing.
Any attempt to circumvent this intent will not be tolerated.
Rule changes or areas re-worded for clarification since last year are
annotated by bold text.
1)
FRAMES - Factory production complete full American passenger frames only.
Frame rails must extend to a point beyond the base of the driver's seat.
Rear clip may be fabricated out of tubing.
Front and rear pickup loop required; otherwise, bumpers or other pickup
point will be used.
2)
BODIES - Same as A-Mod bodies. American
compact passenger car only, such as Pinto, Vega, Monza, Gremlin, Daytona,
Mustang II, etc. Fiberglass or metal
duplicates may be used but must be recognized as factory production, and must
have a complete paint job. (Same as
aluminum A-Mod body). Original
roofline of body must be maintained with a maximum two (2) inch drop rear to
front. Top to be rounded in all
directions. No flat tops.
All cars must have full floorboards and firewalls, both front and rear.
All cars must have sheeting of some sort at rear of car at trunk area.
Rear bumper to deck lid enclosure optional.
If enclosed it should be solid panel at least eight (8) inches and
include car number. If no rear
panel, use five (5) inch by five (5) inch number plate on rear.
Driver and passenger-side windows must have at least twelve (12) inch
vertical opening. Driver's window
must have approved window net. No
spoilers, wings or any other type of air/ground effects are allowed anywhere
inside or outside of the car. No
protruding objects allowed. All cars
must have large legible numbers on both doors and on top in contrasting color
from body. Numbers must be at least
four (4) inches wide and eighteen (18) inches high.
Legible car number at least five (5) inches high and one (1) inch wide on
front and rear. Bodies should extend
no further forward than back of block. Minimum
of three (3) safety bars must be installed in front of driver, and may have
screen attached thereto.
3)
WHEELBASE - 108 inches minimum. 112
inches maximum both sides after races. NO
TOLERANCE!!!
4)
ROLL CAGE - Must consist of continuous hoops not less than one and one
half inches outside diameter and must have a wall thickness of at least .095
inch. Must be frame mounted in at
least six (6) places. Body mounted
roll cages not acceptable. Must
consist of configuration of front and rear hoops connected by tubing on sides or
side hoops in a manner deemed acceptable by the inspector.
Driver's head must not protrude above cage with helmet on while strapped
in driver's seat. Roll cage must
have a 3/16-inch inspection hole in non-critical area.
Must have at least three (3) horizontal bars at driver's door welded to
front and rear of roll cage members.
5)
WEIGHT - Minimum weight is 2,500 pounds with driver after race.
NO TOLERANCE!!!
6)
WHEELS - Wheel width must not exceed eight (8) inches.
No aluminum wheels. Bead
locks allowed on right front and right rear only. Wheel
discs (mud plugs) allowed but must be bolted or welded or foam type.
No DZUS fasteners. Does not
have to be IMCA certified.
7)
TIRES - American Racer G60 or Hoosier G60 or Hoosier 500.
NO EXCEPTIONS!!! Maximum tire
width of nine (9) inches mounted on a conventional one-piece steel wheel with a
maximum width of eight (8) inches. Tire siping, grooving, and grinding allowed.
8)
BRAKES - Disc or drum brakes may be used front and rear.
No aluminum disc or brake calipers allowed.
One (1) brake bias adjustable allowed.
Brakes must be operational on all four (4) wheels and must lock up all
four (4) wheels during inspection.
9)
FUEL SYSTEMS - Gasoline only, E-85 is
allowed. No oxygen-bearing
additives. No pressurized fuel
systems. Fuel cells mandatory.
Fuel cells must be encased in an approved metal container of no less than
20-gauge steel or 1/8-inch aluminum. Fuel
cells must be mounted between frame rails as far forward as possible and using
four (4), two (2) inch by 1/8-inch metal straps, two (2) in each direction.
Bumper must be equipped with a drag loop extending below bottom of the
cell. Fuel cells must not extend
below the rear-end housing. 32-gallon
maximum. No electric fuel pumps.
Must have tip-over valve and flapper valve.
NO EXCEPTIONS!!!
10)
BUMPERS - Bumpers must be used front and rear.
Front bumper must be mounted on frame end and be of a semicircle
configuration with the bottom loop parallel to the ground.
Front bumper must be ten (10) inches high from bottom bar to top bar.
Material must be one and one-quarter inch minimum, two-inch maximum O.D.
steel pipe. Rear bumpers may be
constructed of pipe, square tubing, but must not have sharp edges.
Rear bumpers and nurf bars must not extend beyond width of rear tire.
Bumpers must be able to support car when lifted by wrecker.
MUST HAVE TWO TETHERS ATTACHED TO REAR BUMPER.
11)
SEAT AND SEAT BELTS - Racing seat mandatory.
All cars must be equipped with an approved quick-release type seat belt
and shoulder harness securely fastened to frame and roll cage.
Seat belt material should be at least three (3) inches wide AND CANNOT BE
OLDER THAN TWO (2) YEARS. Seat and
steering wheel may be located to suit driver's taste, but must be kept on the
left side of the car. No center
steer.
12)
ENGINE - Must be OEM Cast Iron Blocks and Heads.
American make V-8 engines only. Engines
must be able to be used in conventional passenger cars without alterations.
Engines must be able to be used in conventional passenger cars without
alterations. Engine casting numbers
cannot be altered. Maximum
cubic-inch limits GM 361 CID, Ford 360 CID, and Chrysler 370 CID.
NO TOLERANCE!!! No Aluminum,
Titanium, or Carbon-Fiber components allowed.
NO STROKER MOTORS!!! Crankshaft
strokes allowed. SEE TABLE 1.
Blocks allowed SEE TABLE 2. Track
has option to enforce these restrictions with a cubic-inch pump gauge, or by
visually checking parts and part numbers. Disqualification
and loss of points if found illegal. MUST
have a one (1) inch Inspection Hole on either side of oil pan with screw-in type
plug.
13)
HEADS - OEM Cast cylinder heads only. For
casting numbers SEE TABLE 3. Gm
maximum 2.02-inch intake valves and 1.60-inch exhaust valves.
Rocker studs may be pinned. Any
screw-in studs allowed. Stamped
steel roller tip rocker arms ONLY!!! Poly
locks allowed. No push-rod guide
plates, no stud girdles allowed. NO
PORTING, POLISHING, OR ANY ALTERATIONS ALLOWED!
Head surfacing minimum of 70cc for cleanup.
Heads must remain 23 degrees.
FORD
- Any cast-iron OEM production head with inline valves.
No SVO heads allowed. Maximum 2.04-inch intake valve and 1.70-inch exhaust valve.
No aftermarket heads. Non-shouldered
rocker
studs
allowed. No guide plates.
No stud girdles allowed. Stamped
steel roller tip rocker arms ONLY!!! Poly
locks allowed. NO PORTING, POLISHING
OR ANY ALTERATIONS ALLOWED!!!
CHRYSLER
- Any cast-iron OEM production head with inline valves.
No canted valves.
No W-2 heads. Maximum
2.04-inch intake valves and 1.70 exhaust valves.
No after-market heads. OEM
rocker arm bar allowed. NO PORTING,
POLISHING OR ANY ALTERATIONS ALLOWED!!!
14)
PISTONS & CAMS - Flat top or dished pistons ONLY!!!
Must use flat tapped cam and lifters.
No mushroom or roller lifters allowed.
No roller or hydraulic cams allowed.
CANNOT ALTER LIFTER BORES. May
use oil restrictors.
15)
ENGINE LOCATION - Rear of engine (bell-housing flange) must be at least 72
inches forward from the center line of the rear axle.
The center of the crankshaft must be within two and one half (2 1/2)
inches of the center line of the car. NO
TOLERANCE!!!
16)
FRONT SUSPENSION - Front suspension must match frame and be in stock location.
Parts must be replaceable from stock OEM type parts from same type
suspension except upper A-frame and A-frame mount.
Tube type upper A-frame may be used.
Fabricated A-frame mount may be used.
Lower A-frame cannot be altered. Adjustable
A-frame and shocks must be steel. Heims
joint. Stock passenger car spindles
only. No fabricated spindles.
Adjustable strut bars may be used on front end only.
Steering box must be stock OEM type and be in stock location.
No rack and pinion steering. No
center steering. Adjustable sway
bars allowed. Outer tie rod and
adjustable sleeve may be replaced by a minimum .625-inch steel rod end and steel
tube. Quick steers are allowed.
17)
SHOCKS - No coil-over shocks allowed either front or rear.
One shock per wheel. One
shock per axel dampening (90-10). No
external adjustable shocks, no Schrader valve shocks, no air/remote reservoir
shocks, no aluminum or threaded body shocks, no canister shocks.
18)
REAR SUSPENSION - Two options: After-market
three-link design or multi-leaf spring design.
All components must be steel. All
mounts and brackets must be welded or bolted solid.
A) Three-link design requirements: must
use minimum 16-inch long lower control arms.
Must use one upper-control arm, solid tube only, (no pull-bar spring to
biscuit assembly), located at the top center of rear-end housing.
Pull bar must run parallel with drive shafts close to center of drive
shaft as possible. (Interior
configuration will be considered on this ruling).
May use minimum 19-inch long panhard bar located behind rear-end housing
or minimum 19-inch long
J-bar
(biscuit or solid type) mounted to a
steel pinion bracket. Measurements
are from center of heim joint to center of heim joint.
Rear spring may be mounted directly over axle housing or use coil-over
eliminators (sliders). Lower spring
perch or coil-over mount must be welded to rear-end housing.
No bird cages or floating mounts allowed.
Must use steel upper weight jack if springs are mounted over axle
housing. B) Multi-leaf spring design
requirements: must use steel
multi-leaf springs with no additional suspension components besides one shock
per wheel. Adjustable lowering
blocks allowed. Springs must be
tethered.
19)
REAR END - Any steel approved OEM passenger car or truck non-cambered rear end
allowed, must be centered in chassis. All
components must be steel, except lowering blocks, axle cap, and drive flange. Safety
hubs (floater) allowed. No
quick-change devices. Inspection
hole in housing required. Mini-spools
and full-spools allowed. Ring gear,
center section and yoke cannot be lightened. Solid
steel axles and one-piece drive flanges only.
20)
CARBURETORS AND INTAKES - Stock Holley 4412 500 CFM Carburetor ONLY!!! NO
ADJUSTABLE METERING BLOCKS ALLOWED!!! Choke
horn must be intact. May remove
choke butterfly. Throttle bore not to exceed 1 11/16 inch. (1.6875).
Must use Edlebrock performance intake. GM
2101, Ford 2121, Chrysler 2176 ONLY, NO EXCEPTIONS!!! Must
use one of two adapters: Mr. Gasket
part no. 1933 or Moroso part no. 64966.
NO
ADJUSTABLE SPACERS!!! Changes made
in attempt to equalize difference between GM, Ford and Chrysler motors.
21)
OIL PANS - Extra capacity oil pans are permitted. No
dry sumps allowed. Oil pump must
mount in stock position.
22)
STARTER - Engine must have working starter and be capable of starting car on
demand. Starter must be in stock location. NO EXCEPTIONS!!!
23)
TRANSMISSION/DRIVE SHAFT - Only 3- and 4-speed manual transmissions allowed. All
forward and reverse gears must work plus a neutral position. With
engine running and car in still position, driver must be able to engage car in
gear and move forward, then backwards. Only
OEM production transmissions allowed. No
'in and out' boxes or quick-change devices allowed. No Berts, Brinns, Falcons,
Layne, or Tonganoxie transmissions allowed. Functioning
shift levers must be in OEM location. One
steel or aluminum flywheel allowed. Must
be bolted directly to end of crankshaft. Mini-clutches
allowed.
A)
Automatic: must be unaltered, two or
three speed, OEM production case with a functioning stock-appearing pump. Must
have an approved scatter shield constructed of .125-inch
by three-inch steel, 270 degrees around top of flex plate. Splined
drive flange coupler with internal pressure relief device, gate valve, or torque
converter. Hydraulic lines may not
extend in to cockpit.
B)
Manual: must be unaltered, three or
four speed, OEM production case. Any
clutch and or mini
clutch allowed. These components
must rotate, consistent with engine RPM, while car is in any gear. Must
use explosion-proof steel bell housing with one hole for throw out bearing lever
or hose, must be 270 degrees around top of clutch and flywheel area.
24)
DRIVE SHAFT - Minimum two-inch diameter, white, steel drive shaft. Steel
slip-yokes only. 360-degree drive
shaft loop required and must be constructed of at least .25-inch by two-inch
steel or one-inch tubing, mounted six inches back from U-joint.
25)
BATTERY - All batteries must be mounted in a safe manner.
26)
HELMETS & FIRE SUITS - Helmets are required and must be worn at all times
car is on the track. All drivers
must wear fire suits of a flame-retardant design/nature. Two-piece
suits are allowed. Fire-resistant
gloves are mandatory and must be worn.
Fire-resistant boots are highly
recommended. Helmets must be SA-95,
SA-2000 or SA-2005. NO M-RATED
HELMETS ALLOWED!!! TAG MUST BE IN
HELMET!!!! NO TOLERANCE OR
EXCEPTIONS OR YOU WILL NOT RACE!!!
27)
EXHAUST - Any collector-type header allowed. Exhaust
must be directed away from areas of possible fuel spillage.
No zoomies.
28)
KILL SWITCH, FIRE EXTINGUISHER, and WINDOW NET - A kill switch is required
within easy reach of the driver. This
switch must be clearly marked OFF and ON. Weights
and or lose objects are not allowed in the driver's compartment. All
cars must be equipped with quick- release type window net on driver’s door. No
rear-view mirrors of any kind. Recommend
having a fire extinguisher in the car!!! No
radio communication or sound equipment of any kind.
29)
GAUGES/ELECTRONICS - 12-volt ignition system only. HEI
distributor only. OEM firing order
cannot be changed. Ignition rotor,
cap, coil and module must remain OEM appearing. No
ignition boxes, remote coil or accessories. All
wiring must be visible for inspection. The
only gauges allowed are analog-type gauges.
Analog tachometer allowed (memory recall allowed). No
electronic traction control allowed. No
digital gauges of any type allowed.
30)
THE TRACK AND ITS OFFICIALS CAN INSPECT CAR AT ANYTIME AND ANYWAY DEEMED
NECESSARY!!!
TABLE
ONE- Crankshafts strokes allowed:
GM
302 CID - 3.0
305 CID - 3.48
307 CID - 3.25
327 CID - 3.25
350 CID - 3.48
FORD
289
CID - 2.87
302 CID - 3.0
351 CID - 3.50
CHRYSLER 318 CID - 3.31
340
CID - 3.31
360
CID - 3.58
TABLE
TWO - OEM Blocks allowed:
GM - 3892657, 3914678, 3932388, 3932386, 3956618, 3970010, 3970014,
10036033,
10066036,
14010207, 14010209, 14016376, 14016379, 14088548, 14093938, 14101148,
10066034, 10066098, 10105123.
FORD - Any OEM production block.
CHRYSLER - Any OEM production block.
TABLE
THREE - Heads
GM - 3986336, 3986339, 3986339x, 3986388, 3932441, 3973487, 3973487x,
3973493,
3951598, 468642, 333882, 3998920, 3998991, 3998993, 3998997.
FORD - Any OEM production head with inline valves. (NO CANTED VALVES AND
NO SVO HEADS)!!!
CHRYSLER - Any OEM production head with inline valves. (NO CANTED
VALVES!!! AND NO W-2 HEADS)!!!
MUST
HAVE VISIBLE NUMBERS ON BACK OF CAR.
REFER
TO GENERAL CAR AND SAFETY RULES in "Track Rules & Regulations" for
more pertinent information.