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2012 MOUNTAIN SPEEDWAY SPORTSMAN MODIFIED RULES

 
To be eligible for competition, all cars must meet requirements set forth in either the current NASCAR rulebook or R.O.C. rulebook as far as body, chassis, and drive train is concerned. The only exceptions will be that the engine, clutch, ignition, weight, wheel, and tire specifications will be replaced with the following:
 
Cars in this division have the option of utilizing different engine combinations from similar divisions at various other racetracks. The engine rules detailed in sections A and B apply to the home track engines at Mountain Speedway. All other engine combinations use rules based on each individual tracks’ rulebook. In order to blend these engine combinations together as fairly as possible, some deviations from each tracks’ rulebook are allowed. These deviations are detailed in section C of the Engine rules. Obviously, if your engine is legal at any of the other listed tracks or series, it will be legal at this speedway-as long as weights and left side percentages are adhered to. In many cases, additional modifications may be allowed as detailed in section C.
 
A. Mountain Sport Modified 4 barrel Engine including clutch, ignition, and carburetor.
 
1. Any overhead valve V-8 American manufactured production engine permitted. Engine block must be production type cast iron block. Aftermarket or DEM performance blocks are permitted as long as they are an exact replacement for production block. No large bore or tall deck blocks permitted.
 
2. Stock stroke and stock bore (+.060 max) Chevrolet engines must have a max. bore of 4.060 and a max stroke of 3.480 inches. Ford engines must have a max bore of 4.060 and a max stroke of 3.500 inches. Mopar engines must have a max bore of 4.060 and a max stroke of 3.580 inches.
 
3. Engine combinations resulting ina cubic inch diplacement larger than 360 cubic inches will require 6.9 pounds of weight for every cubic inch over 360 cubic inches be added to total weight of car.
 
4. Max. compression ratio of 9.0: 1 on any cylinder.
 
5. No porting, polishing, or casting alterations of any kind permitted to cylinder heads or intake manifold.
 
6. Edelbrock Performer PN #2101 and 2116 for Chevrolet engines, PN# 2181 for Ford engines, and PN#2176 for Mopar engines.
 
7. Stock production cast iron heads ( no bow tie or bowtie vortec heads) The following cylinder heads are also allowed: (all port numbers must be visible)
 
Chevrolet:   
World Products: #4266 and #4267
EngineQuest: #CH 350C, CC 170BA, CC 170BAZ, CC 167CSZ,  CC 167 CS   CC  167ES2, and CC 167 ES
Dart: 100-210-70, 100-210-10, 100-242-66, 100-243-65, 100-263-64, 100-243-70
Pro-Topline: #2236494906
 
Ford: World Products: #5303B
Mopar: EngineQuest #CH318B
           
8. Flat top or dish pistons only.
 
9. Ant flat toppet or hydraulic roller camshaft allowed.
 
10. Stock dimension magnetic flatt tappet or hydraulic roller lifters madatory. If hydraulic lifters are being used, the valve springs may not exceed 1.300 inches in diameter. Retro-fit hydraulic roller lifters are permitted. No modifications or shimming of hydraulic roller lifters allowed.
 
11. Roller rockers allowed, no shaft style rockers (unless factory issued). No stud girdlesor rev-kits.
 
12. Stock points type or stock type electronic ignition only. No MSD ignition boxes.
 
13. No automatic transmissions permitted.
 
14. Multidisc clutch allowed. Min. disc diameter will be 7 inches. No carbon fiber clutchparts.
 
15. Holley 650 cfm carburetor #PN 4777 or 80541-1 only.
 
16. Any carburetor spacer with a max. thickness of 1 inch measured at any location permitted. One gasket only on each side of spacer plate. Max. gasket thickness allowed is .062 inches.
 
17. Any headers allowed. (except 180 degree)
 
18. GM performance crate engine #602 is permitted.
 
 
B. Mountain Sport Modified 2-barrel engine (including clutch, ignition, and carburetor)
 
 
1. Any overhead valve V-8 American manufactured production engine permitted. Engine block must be production typer cast iron block. Aftermarket or OEM performance blocks are permitted as long as they are an exact replacement for production block. No large bore or tall deck blocks permitted.
 
2. Stock stroke and stock bore ( +.060 max) Chevrolet engines must have a max. bore of 4.060 and max stroke of 3.480 inches. Ford engines must have a max bore of 4.060 and a max stroke of 3.500 inches. Mopar engines must have a bore of 4.060 and max stroke of 3.580 inches.
 
3. Engine combinations resulting in an cubic inch displacement larger than 360 cubic inches will require 6.9 pounds of weight for every cubic inch over 360 cubic inches be added to total weight of car.
 
4. Max. compression ratio of 11.0:1 on any cylinder.
 
5. No porting, polishing, or casting alterations of any kind permitted to cylinder heads or intake manifold.
 
6. Edelbrok Performer PN# 2101 for Chevrolet engines, PN#2181 for Ford engines, and PN# 2176 for Mopar engines. Edelbrok Performer RPM PN# 7101 for Chevrolet engines, PN #7181 for Ford engines and PN# 7176 for Mopar engines are also allowed but 25 pounds must be added to min. car weight.
 
7. The following are the permitted cylinder heads:
           
Chevrolet: GM performance Bowtie #PN 12480034
Dart Iron Eagle PN# 10310010 PF and PN# 10310010P
 
Ford: Ford Motorsports  PN# M-6049-N351
World Products PN# 053030 and 053040
Dart 10300010, 10300080, 13400010, 13400010
                       
Mopar:  Mopar performance PN# 4539493, 5249574, 4529994
Enginequest  CH# 318B
RHS 20300 and 20301
 
8. No Min. weight or Min. journal size 4 crank shaft or connecting rods.
 
9. Flattop or dish pistons only.
 
10. Any flat tappet or roller cam chaft allowed. Max. valve spring O.D. of 1.580 inches. Max. valve lift of 0.700 inches measured after race with no adjustments permitted.
 
11. Stock dimension lifter bores. Lifter bores may be bushed.
 
12. Stock dimension magnetic steal flat tappet or roller lifters, 0.842 for Chevrolet engines, 0.875 for Ford engines, 0.904 for Mopar engines.
 
13. Roller rockers allowed, no shaft style rockers (unless factory issued) . Stud Girdles allowed. No rev-kits allowed.
 
14. No gear drive or belt drive timing sets permitted.
 
15. Wet sump oil systems only. No external oil pumps or vacume pumps. Oil pans must be steal or aluminum.
 
16. Any headers allowed. (except 180 degree).
 
17. Holley 500 cfm carburetor PN# 4412 or #80583 only. Must pass all track gauge checks. Throttle plate screws may be trimmed flush with  shaft.
 
18. Any carburetor adaptor with a max thickness of 1 inch measured at any location permitted. One gasket only on each side of adaptor plate. Max. gasket thickness allowed is 0.062 inches.
 
19. Stock type electronic ignition or MSD ignition system allowed. If MSD ignition is used, only the following distributors are permitted:
 
Chevrolet PN 85501, 85551, or 8570
Ford PN 8584 or 8578
Mopar PN 8534
 
Only the following MSD ignition boxes are permitted: PN# 6201 and 6200 (6A) and 6425 and 6420 (6AL) , 6430 (6ALN) or 6631 (HVC). Only one ignition pickup, one ignition box, and one coil allowed.  Connectors as well as all other parts must remain unaltered on ignition box and distributor. track officials reserve the right to exchange any distributor or ignition box for track supplied unit at any time or confiscate any ignition part for testing. All wiring from ignition box to distributor must be exposed and visible for tech inspection. Wiring will be inspected on a routine basis. Wiring from box to distributor as well as wiring to tach must be free of splices, open connectors or insulation breaks. All unused wires must be cut flush with box.
 
20. Multi-disc clutch allowed. Min. disc diameter will be 7 inches. No carbon fiber clutch parts.
 
21. No automatic transmissions permitted.

C. OTHER ENGINES -

1. SST type cars may use DART Iron Eagle 200 cc Platinum head.

2. SST type cars may use Edelbrock Performer RPM intake manifold, Part #7101, but will be required to add 25 pounds to minimum weight.

3. SST type cars may use any 1-inch carburetor spacer.

4. SST type cars with 12:1 compression ratio must add 100 pounds to minimum weight

5. Wall Stadium Spec engines must use a one-inch maximum carburetor spacer.

 

ALL ENGINES

1. Oil pans on all cars may be constructed of steel or aluminum.

2. All cars must use wet sump oiling systems. All oil pumps must mount in stock position.

3. NO vacuum pumps permitted on any engine.

4. No minimum journal diameter for main bearings or connecting rod bearings. No minimum weight for crankshaft or connecting rods. This applies to all cars in this class, regardless of series or track affiliation.

5. All engines will be subject to inspection by Mountain Speedway officials. If necessary, seals will be removed as part of the inspection process. It is advised that seals on crate engines be removed and replaced with factory type fasteners to facilitate inspection process.

All “Other Eligible Cars” must meet all rules and requirements of their claimed home track’s rule book (including Carburetor). Interpretation of these rules is subject to the discretion of Mountain Speedway Officials. These cars must declare track/series affiliation at time of registration.

 

FRAME HEIGHT

1. All cars must maintain a 2” frame height, with driver seated in driver’s seat-after race.

WHEELS AND TIRES

NOTE: Track tire will be required for all cars. Call speedway office for tire info.

1. Only 15” diameter by 13” (maximum) width five lug reinforced magnetic steel racing wheels permitted.

2. Any offset permitted.

3. Only solid one piece, heavy duty 5/8” magnetic steel lug bolts and standard one inch hex, fully threaded and solid magnetic steel lug nuts will be permitted.

4. No bead lock wheels permitted.

TRACK WIDTH

1. Maximum width of 83 ½ inches-measured bead to bead.

WEIGHT

1. All cars (Mountain, Wall, SST, SK, Thompson-Sunoco) must weigh 2600 pounds minimum and have 56% maximum left side weight, with driver seated in driver’s seat-after race.

***(unless specified below)***

Wall Stadium Spec Engine Modifieds - Wall Stadium Modifieds with Wall spec. engine must weight 2675 lbs., maximum 56% left side weight with driver in driver's seat-after race.

Wall Sportsman Modifieds, SST Lites, SK Lights must weigh 2525 lbs., maximum 58% Left Side weight with driver in driver’s seat-after race.

Wall Stadium Stock Clip Sportsman Mods must weigh 2525 lbs., maximum 58% Left Side weight with driver in driver’s seat-after race. May run Holley 4-barrel 650 cfm carburetor, Part #4777 or #80541-1 (bolted directly to intake manifold) and headers with mufflers.

CLUTCH - All “Other Eligible Cars” may use a multi-disc (made for racing) clutch. Minimum disc diameter will be 7 inches. No carbon fiber clutch parts.

AXLES - NO TITANIUM AXLES ALLOWED IN ANY CAR.

MUFFLERS/HEADERS - Mufflers are MANDATORY on ALL cars. Headers on all cars may be constructed of steel or stainless steel only.

SPOILERS - For all cars, spoiler must be a maximum of 8 inches high by a maximum of 48 inches wide. The rear spoiler may not extend past the rear edge of the rear bumper at any time. A maximum of 35 ½ inches, measured from the ground to the spoiler mounting point-will be permitted. Rear spoiler must be solid clear polycarbonate (minimum ¼ inch thick). No lettering is allowed on spoiler.

SCANNERS/RADIOS/MIRRORS- No radio communication between drivers and crew members or spotters. Driver must have scanner and monitor race director and tower at all times. Spot mirror is allowed. No rearview mirrors.

NOTE: Enforcement and interpretation of all rules is subject to the discretion of Mountain Speedway officials. All Mountain Speedway gauges, scales, and measuring equipment will be the absolute last word in any and all disputes.

GENERAL

Since the goal of this division is to blend a wide variety of limited Modifieds into one competitive class, rules may, from time to time, be adjusted to address over-competitive types of cars. In the event car counts are such that a further sub-division of the class is necessary, steps will be taken to address that situation.