6,000 lb. Classic Modified
1. Maximum weight is 6,000 lbs.
2. NO Engine RPM limit
3. Any speed, any gear and no shifting of T/A or like transmission is allowed.
4. All tractors must be neatly painted.
5. Tractors are intended to look like a stock farm tractor that has a automotive V-8 neatly installed.
6. No extended or widened hoods.
7. Raised carburetor enclosures are allowed.
ENGINE
360cid limit with 1% tolerance. NO big blocks, NO turbochargers or superchargers. One automotive production Cast Iron Block and Cast Iron Heads only. Blocks and heads are to remain unchanged in outside appearance. No overhead cams, no tunnel port manifolds, no more than 2 inches of carburetor spacers, no magnetos exhaust pipes or headers must
be turned straight up or down, no flap type covers on exhaust, any single automotive or agricultural carburetor is allowed. Electric fans, water pumps and fuel pumps are allowed. Pump gas and racing fuel is allowed. NO alcohol is allowed.
FUEL
1. Tractors are to be naturally aspirated with a single gasoline carburetor.
2. No nitrous oxide, water and alcohol injection are not allowed.
3. No nitro methane or nitro methane fuel additives allowed.
4. E-85 is allowed
TIRES/WHEELS
1. 18.4 x 38 tire size is the maximum. Any cut and any rim width.
CHASSIS
1. Stock frames or like replacements are allowed. Example would be a tractor with cast iron tub chassis may convert to side rail frames.
2. Agricultural Sheet Metal and Ag Transmission rear end and axle housing no newer then 1975. Any manufacture sheet metal is allowed as long as it is from the same manufacture.
3. No lengthened or widened hoods.
4. All tractors must have a wide front end.
5. Center line of the front axle may be no more than 12 inches in front of the OEM axle location.
6. Batteries and fuel tanks may be remote located in front of grill.
7. No part of the tractor including the front weight bracket shall not exceed more than 11 feet in front of the center line of the rear axle.
8. Weights may not extend beyond the rear most point of the rear tires.
HITCH
1. Point of the hook must not exceed 20 inches from the ground or be no less than 18 inches from the center line of the rear axle.
2. Adjustable draw bars must be stationary in all directions.
3. Top of hitch adjuster must not be attached above the center line of the rear axle.
SAFETY
1. REQUIRED: All drivers are required to wear approved fire suit and wear a DOT certified helmet.
2. Wheelie bars are required and must support the weight of the tractor.
3. Rear mounted kill switch is required. Switch must kill the circuit to the ignition as well as the fuel pump(s).
4. Dead man style throttle is required.
5. All tractors must be equipped with roll over protection whether it be OEM or multiple bar design.
6. Seat belts are required when hooked to the sled.
7. All tractors must be equipped with rear fenders.
8. All tractors will be equipped with either a SFI scatter blanket of 3/16 inch steel band over the clutch and flywheel area.
9. SFI flywheel and clutch required.
10. All drive-line couplers must be shielded 360 degrees.
11. Engine side covers are required and cover the area from the base of the cylinder head to the top of the frame rail or oil pan.
12. Wheelie bars must not be connected to the tractors hitch.
13. Harmonic balancers are required to shield 360 degrees.
14. All tractors must be equipped with fire extinguisher within reach of the driver.
15. All tractors must be equipped with front stabilizer bars or ski's. Ski's must be 4 inches off the ground and must be attached to the frame by at least 2 points of contact.
Full Pull Productions Classic Hot Rod Rules:
Tractor must be 1972 or older and be an agricultural wheel drive tractor. No industrial or experimental tractors.
Engine must be naturally aspirated V-8, with a cubic inch displacement no larger than 521.16 c.i. Block and cylinder heads must be cast iron. Single carburetor, no fuel injection, no turbo chargers or forced air induction of any kind. Aluminum manifolds are permitted. Headers must exit in an upward direction. Motor must be parallel with input shaft of transmission and be mounted in the center of the frame. Spark plug guards must be in place to deflect downward or contain spark plug.
No power shift or locking differential, factory TA permitted.
Kill switch of a breakaway type is required and must be wired to MSD and fuel pump. Switch must be accessible and functional. Subject to random inspection.
Crank driven engine cooling fans must be a minimum rating of 8,000 RPM or electrically driven.
It is recommended that the fuel tank be mounted in front of tractor.
Maximum allowable RPM’s will be no greater than 6000. All ignitions must use a MSD system with a 6000 maximum RPM limiter chip or limiter box. Must be equipped with a recall tach. No more than 100 RPM variation over 6000. If checked and tach recall is cleared, it is an automatic disqualification. If tractor is over 6100 RPM’s tractor can be checked with handheld tach as a backup for accuracy.
Fuel: Gasoline fuels only with a maximum of 750 specific gravity, no E85, no alcohol, no pressurized fuels, no nitrous oxide, no oxygen accelerate, no nitrogen methanol, and no propylene oxide. Racecar gasoline may be used.
Crank harmonic dampener hub must be SFI 18.1 rated or a steel shield must be constructed tightly around a nonrated pulley or hub to contain it in all directions of exit.
Pressure plate must be competition type and be SFI approved.
Tractors built prior to 1/1/2006 must have a steel constructed flywheel of greater than 1 ¼ “maximum thickness. Cast iron flywheels are not permitted. Flywheels must be accessible for inspection. Tractors must have a steel shield around flywheel and clutch with a SFI blanket with a minimum rating of 4.2. The shield must be made of .25” (¼”) minimum thickness and minimum with equal to the thickness of the flywheel and pressure plate assembly. Shield may be attached to bell housing, engine, or chassis.
Tractors built after 1/1/2006 must have a SFI rated competition designed flywheel, clutch, and pressure plate. Tractors must also have a steel bell housing with SFI rating of 6.1, 6.2, 6.3, or a SFI rated blanket with a 4.2 rating.
Universal joints, chain couplers and drive shaft must be surrounded by .25 (1/4”) steel the entire length.
Air cleaners must be under the hood.
Steering may be rack and pinion or hydraulic.
Diesel conversions are allowed but must run on gasoline with no injection.
Throttle has to be dead man type with return spring.
Frame ties are mandatory and must be mounted to the rear end. Ties must extend ahead of the rearmost mounting location of engine block. Ties must be able to support the tractor with bolts removed from rear end and transmission.
Wheelie bars are required and should not be attached to the draw bar in any way. Bars must extend beyond rear most plane of tire and be able to support the tractor. Tech crew has right to put jack under skid pad. Skid pad height is 10 inches maximum.
Fenders and roll bars are required. Roll-over protection must extend higher than the driver’s helmet.
Tractor has to be equipped with a fire extinguisher ABC or Halon for all.
Sheet metal must be stock appearing dimensions. Must be in stock location as measured from center line of rear axle. Sheet metal can be from a different tractor and must be older than 1972. Tractor wheelbase may not exceed 102” from center of rear axle to center of front spindles. Front wheels must overlap rear tires when sighted from front of tractor. Rear end, transmission, and axle housing must appear stock. Internal modifications are allowed but transmission shafts must remain in stock location. No differential locks permitted in rear end. Front end and frame rails can be fabricated, but must be safe for the heaviest class. Frame rails may extend to rear axle. Maximum overall length, including weights measured from center of rear axle is 12 feet.
Draw bar must not exceed 20” in height and not less than 18” from center of rear axle. Drawbar must be stationary in all directions with a minimum of 3” hole.
Drivers must have a SFI 3.2a/1 or better jacket and SNELL crash helmet. Must have a valid driver’s license. Seat belt or harness must be worn.
Drivers must stay on the seat at all times. Hands must be on the steering wheel, hand brakes, hand clutch, or throttle at all times during pull. Double clutching is prohibited.
Technical inspections: All tractors must be pumped or measured. Ray Bell – Lisbon, Ohio is the USA-East Appointed Tech Director for the Class. Pans must be sealed with USA-EAST wire seal on two oil pan bolts. No other seals accepted. One head bolt will be painted on the engine to insure engine hasn’t been completely torn down after inspection. Tractors without the wire seal on the oil pan or paint on the head bolt will not be allowed to pull. When performing the pump test, engine cubic inch can be a maximum of 521.16. Provisions must be made to put on a “seal” on the engine after the tractor has been cube checked. Competitors must be able to have their engine pumped at ANYTIME during the pull season. A 1% variance will be permitted.
Tires: 18.4 x 38 maximum allowed bias or radials with any cut.
Central Ohio Tractor Pulling Association
WEIGHT: 6000 #
TIRES: 18.4 x 38 maximum
AGE OF DRIVER: 16 years or older, under 18 years must have parental consent.
AGE OF TRACTOR: 1972 and older, no home- made tractors
FUEL: No pressurized fuels, no nitrous oxide, no nitrogen methanol, and no propylene oxide. Racecar gasoline, Alcohol, and oxygenated fuels may be used.
DRAW BAR: Drawbars must not exceed 20 inches in height or less than 18 inches from center of axle to hooking point. No part of draw bar may extend rearward beyond point of hook. No part of drawbar is to be attached to any point higher than the center of rear axle. Drawbars must be stationary in all directions. No clevis, absolutely no turnbuckles.
ENGINE RULE: Must be 410 cubic inches or smaller, 6 cubic inches may be added to engines that require a fresh re-bore, no engine may be larger than 416 +0 cubic inches, Must be an industry standard small block, no big blocks. Must be a cast iron block, cast iron heads, maximum eight cylinders, two valves, one spark plug per cylinder, Camshaft in block. The (Pump) is a Tech tool only; engines under protest may be subject to a tear down. All Pullers have the tear down option. All engines may be subject to a tear down by the COTPA Tech Inspector and or COTPA Officials as they deem necessary. The (Engine Rule) will be in effect through the pulling year 2020. Center of axle to rear of block (where bell housing bolts on) is to be a maximum of 72 inches
MANIFOLD, CARBURETOR: One four barrel naturally aspirated carburetor, 4150 base, 750 CFM. No predators, no dominators, no aerosol carburetors. No fuel injection, no throttle based injection. Carburetor will be inspected with a No Go gauge (1.400 top and 1.700 bottom. All intake manifolds can be low-rise type. No tunnel-ram, no sheet metal/ aluminum intakes, no casted sheet metal type, no welded manifolds allowed. Headers must exit in an upward direction.
IGNITION: All ignitions must use a MSD model 6AL or 7AL-2 system with an RPM limiting chip. Tech inspections performed by using MSD model 89952 RPM Module/Chip Tester.
Engine RPM-
1) Tractor engines will have an 8000 maximum RPM limit.
2) Tractors must use an MSD model 6AL or 7AL-2 system with chip limiter.
3) Boxes must be easily accessible for officials to tech.
4) Boxes may not be tampered/ modified. Rivets must be original. If you drill a rivet out, you will have to buy a new box. If factory sealant/ sticker is broken, a new box is mandatory.
5) Only the wiring per MSDs wiring diagram is allowed, and must be plainly visible. No other wires may be attached to any of the MSD factory wires other than as specified per MSDs wiring diagram.
HOOD, GRILL, TRANSMISSION, REAR END, AXLE: All Sheet metal to include Hood, Grill, Fuel Tank, (if part of sheet metal) Side metal, and Screens must be for that make and model and must maintain original dimensions in all directions (width, height and depth) but could be moved forward a maximum of 8 inches as a complete unit/assembly. Sheet metal must be 1972 or older. Some sheet metal modifications are allowed contingent upon Hot Rod committee approval. Agricultural rear ends must also be 1972 or older. Crossing Sheet Metal with Different Manufacturer is permissible. Bell housing and transmission may be removed if they were designed to be unbolted from the rear end at the factory. Front ends may be homemade, maximum allowable wheelbase of 100 inches from center of rear axle to center of front axle or manufacturer stock length if greater than 100 inches.
TOTAL LENGTH OF TRACTOR: Tractors maximum allowable length is 11 inches from center of rear axle to the furthest point forward, including weights.
SAFETY EQUIPMENT: Helmet and fire suit, wheelie bars, ski bars, kill switches, fire extinguishers, fenders, SFI damper, SFI flywheels and pressure plates, SFI bell housings, engine side shields must be incorporated. Drive shaft from bell housing to transmission must be shielded. Roll cages must be capable of supporting tractor and driver. No steel fans. All tractors must have wide front axles with a minimum of 32 inches between inside of tires. All electric fuel pumps must be wired to the kill switch. Neutral safety start switch is required. NO factory cast iron tub frames allowed. COTPA General Rules apply.