TENNESSEE NATIONAL RACEWAY/ THUNDERHILL RACEWAY
MODIFED STREET STOCK RULES 2015
Look alike bodies; factory type or Reproduction Aluminum Panels OK, NO CLIP CARS
1964 or newer OEM perimeter American rear-wheel drive passenger car frame only
Minimum Wheelbase 101"
Hulling out around wheels & tires are okay
Upper control arms can be tubular but no adjustable
Wedge bolts all 4 corners are okay
Racing Springs and shocks are okay steel-non-adjustable
Floor pans must be stock or steel; right side of car can be stock and/or boxed
Frame connectors for unibody cars mandatory
-602 Crate 8 Inch Spoiler
-362 Cub In 8 Inch Spoiler
-Over 362 4 Inch Spoiler
NESMITH ENGINE RULES
Engine Option 1:
1. Gm Part Number 88958602 , Weight 3,000
2. These Engines Are Sealed At The Intake Manifold, Cylinder Head, Front Cover, And Oil Pan With Special Twist Off Bolt Heads Originally From Gm. Crate Usa Seals Allowed, No Rm Bolts, For Any Other Sealing System Contact Crate Racin Usa For Approval. Crate Engines Must Not Be Altered, Modified Or Changed From Factory Specs.
3. The Sealed Engines Must Remain Intact And Not Be Tampered With; Any Seals That Have Been Removed Or Tampered With Will Make The Engine Illegal And Not Eligible For Competition. The Penalty For Anyone Tampering With Seals, Modifying Any Internal Engine Parts, Changing The Parts From Stock As Delivered Sealed From The Factory Will Be Subject To Expulsion From Racing With Any Crate Racin' Usa Sanctioned Event For The Remainder Of Season And Future Seasons.
4. No Changes Are Allowed To The Engine - Intake Manifold, Heads, Valve Covers, Front Cover, Oil Pan, Harmonic Balancer Or Any Other Part / Or Parts On / Or In Engine.
5. No Vacuum Pumps.
6. All Crate Engines Must Remain Stock As They Came Sealed From The Factory. Crate Engines Must Not Be Altered, Modified Or Changed From Factory Specs.
7. Engine’s Gm Serial Number And When Applicable Crate Usa Build Certification Number, Must Be Clearly Visible To Series Technical Inspectors.
8. 4. Any 4 Barrell Carburetor. May Run 1” Maximum Carburetor Spacer .040” Tolerance, At No Point May Spacer Extend Into Intake Manifold Area. With 2 Standard Thickness Carburetor Gaskets, .070” Maximum Thickness.
Engine Option 2:
1. Minimum Weight 3200 Lb. 362 Cubic Inch Maximum, Factory Steel Blocks, And Oem Street Production Straight Plug Steel Heads, Rhs Vortec Part #12407, Or Engine Quest Part #350c, Stock Replacement Head Ok(173cc Max Intake Runner Volume No Tolerance). No Porting Or Polishing Heads .
Max. Valve Size, 2.02” Intake, And 1.6” Exhaust. Any Intake Manifold, No Porting And Polishing. Any =Other Cast Iron Head Add 100lb, Aftermarket Cast Iron Head Must Have Max 2.02” And 1.6” Exhaust, And No Porting Or Polishing Of Heads.. No Aluminimum Heads. Steel Or Cast Cranks And Rods, Aftermarket Replacement Cranks And Rods Ok. No Lightened Or Knife Edged Cranks, No Exotic Material Cranks Or Rods (Ex. Aluminum Or Titantium).
2. Flat Top Pistons Only. Any Flat Tappet Camshaft Only. No Roller Cams. Timing Chains Only No Gear Drives.
3. Stud Mount Rockers Only. No Stud Girddles. Stock Diameter Valve Springs Only, 1.250” Maximum O.D. Beehive Springs Allowed, 1.310” Maximum O.D., Any Manufacture (Chevy, Ford, Or Dodge), Or Any Cylinder Head, No Double Valve Springs.
4. Any 4 Barrell Carburetor. May Run 1” Maximum Carburetor Spacer .040” Tolerance, At No Point May Spacer Extend Into Intake Manifold Area. With 2 Standard Thickness Carburetor Gaskets, .070” Maximum Thickness.
Engine Option 3:
1. Any Engine Larger Than 362 Cubic Inches, 3400lb. Minimum. Must Use All Other Intake, Cam, And Cylinder Head Rules From Engine Option 2.
CARBURETOR: (option 3)
-500 Cfm 2 Barrel. No Porting Or Polishing Changing Of Boosters Or Altering Of Base Plate, And Throttle Shafts In Any Way.
-2 Barrell Carbs Checked With Go-No-Go Gauges Top To Bottom.
- May Run 1” Maximum Carburetor Spacer .040” Tolerance, At No Point May Spacer Extend Into Intake Manifold Area. With 2 Standard Thickness Carburetor Gaskets, .070” Maximum Thickness.
Engine Setback Rule:
- Engine Must Be Mounted In Stock Location, Center Of Chassis. #1 Spark Plug Must Be In Front Of Or Cenerline Of Upper Ball Joint.
-Weight Penalties Of 50lb Per Will Be Added Forward Of Water Pump For Improper Set Back.
Nesmith Motor, Weight & Carb Rules
-If you have Half Firewall Or Rightside Floor Pan Removed, No Extra Weight To be Added, But Must 50lbs Next Motor
-No Vacuum Rule With 2 Barrel
-2 Barrel Must 4412 500 Cfm Max & Must Go/No/Go Gauge
-Bert Or Brim Transmission, Add 100 Lbs
After market brakes are okay
Adjusters for brakes are okay
Any ignition No magnetos
Stock 9” Ford or floater rear ends are okay
Panhard bars; 4 links stock
No 5th arms
Trailing arms must be in stock location and can be adjustable steel only
If mount on car has to be replaced it must be same size and in stock position
Panhard bars must be connected to back side of rear end
American Racer G60 or KK704 stamped or non-stamped tires are permitted.
Hoosier G60, stamped or non-stamped are permitted. H500 will be permitted.
Any Steel Belted D.O.T. 60 series tire. 275/60/15 Maximum. No Mud/Snow tires.
Grooving and/or siping is permitted
Altering tires with any chemicals which alter the manufacturer's baseline-settings of the tire is not allowed.
Rear Tires must punch 50 at anytime.
Steel Wheels only
Must be 15" in diameter and up to 10" in width max.
Steel bead locks may be used on the right side only.
Wheel covers are permitted on right side wheels only. Inner mud plugs are permitted.
Wide five wheel adaptors are not allowed.
Steel or aluminum spacer between hub and wheel is permitted, but overall width of racecar cannot exceed 78".
Quick steer is okay