|Light & Heavy Pro Stock Tractors
Class Rep: Robert Alves - Light
Rob Bauman - Heavy
1. Light Pro Stock - 7000 lb alcohol / 7500 lb diesel/gas
Heavy Pro Stock - 9,000 lbs & 10,000 lbs
2. Tractors may not weigh light by more than 1,000 lbs of the class being pulled
3. Weights must not extend rearward beyond rear tires. Weights must be securely fastened on brackets. Weights must not obscure
4. Light Pro Stock tractors may move up to a Heavy Pro Stock class provided the tractor meets all Heavy Pro Stock rules.
1. Engine must be manufacturer's specific for that tractor.
2. Cast iron cylinder heads only. No aluminum heads, exception of Deutz OEM heads. No overhead cams.
3. Maximum Displacement: 7000 lb alcohol / 7500 lb diesel/gas
Weight handicap can be reviewed and adjusted at any peiod
1. 410 cid - unlimited turbocharger size with an inter/after cooler (diesel) (gas)
2. 315 cid - may run twin chargers up to 3x4 with intercooler (diesel)
3. 370 cid - maximum of a 3x4 turbo and NO inter/after cooler allowed (alcohol)
9000 lb & 10000 lb
Engine max 505 ci engine turbocharger only (both classes) - diesel only
If engines are not factory OEM engine must match heritage lines of manufacturer
All Pro Stock tractors must be cubic inch tested and sealed before the pulling season or first appearance of vehicle during the pulling
season. If the cylinder head is removed the bore and stroke can be measured or it can be done with OTTPA cubic inch tester with the
engine complete. If the seal is broken the vehicle must be rechecked before pulling again. The seal will consist of a wire going
through two drilled oil pan bolts. Engine must be checked by appointed Tech committee.
4. Fuel Systems: 7500 Diesel, Gas or Alcohol
9000 & 10,000 & Diesel Only
NO SECONDARY FUELS
5. Diesels are limited to maximum of a "P" series pump. Only one plunger per cylinder. No Sigma pumps.
6. Gas powered tractors are limited to one carburetor.
7. No engine driven fans allowed.
8. Tractor must have a catch can to collect all liquids from the engines vents and overflows. Catch cans must be able to collect all liquids
normally expelled from the tractor during the pull. Cans must be a closed container with an inlet and a vent.
9. Turbo charged engines must have two 3/8" grade five bolts in the vertical portion of the exhaust pipe. Bolts to be installed 90
degrees to each other and within 1" of each other.
10. Tractors require one cable that must surround the engine block and head. This cable must be placed between the first and second
cylinder through the exhaust manifold port area. The cable must be minimum of 3/8 inch thickness and must have a minimum if two
clamps at the splice. The cable must have approximately 4 inches of slack.
Clutches / Flywheels
1. Tractor must use approved blankets covering clutches and flywheels. Tractors must be continually equipped with all clutch assembly,
flywheel and bellhousing components that are equal to or exceed the minimum safety requirements as defined by SFI specifications. The
flywheel, clutch, pressure plate components must be made of steel, aluminum or ductile iron. Positively no gray cast iron allowed. Owners
must sign a guarantee of compliance and waiver form.
1. No tricycle front ends.
2. Tractors maximum length of 13 feet from centre of the rear axle forward, weights included, front mounted hitches "tow loops" excluded
3. The clutch housing, transmission case, rear end housing and axle housing must be OEM with no aluminum replacements
4. Tractors must be within 6" of the original wheelbase
5. Sheet metal on tractors may be updated but tractor's specs must remain as per original tractor
6. Fenders must be constructed so that with the driver seated no part of the drivers body can come in contact with rear wheels(hands
on steering wheel)
7. Stabilizer bars must extend 2 inches beyond the edge of the rear tires. Stabilizer pads must be a minimum of 24 square inches
each. The pads to be mounted maximum height of 8 inches off the ground when the tractor is parked on a flat surface. The pads must
be a minimum of 24 inches from the outside edge of one to the outside of the other pad. Vertical bars to extend up from rear edge
of the pads minimum of 12 inches. Vertical bars are to be made form equal strength material as the stabilizer bars. Stabilizer bars
must be capable of supporting tractors weight of the heaviest class it will pull in. No wheels allowed on stabilizer bars
8. Side shielding of 1/16 inch steel or equivalent strength metal must cover from the hood to the lower swing of the crankshaft and
be securely fastened frame rails excepted
9. Turbocharger not contained within the side shield and hood must be shielded 360 degrees with 1/16 inch steel
10. Light Pro Stock tractors must have two supports of sufficient strength. Supports must be bolted from the frame to the differential
to prevent tractor from splitting
11. Tractors require a front tow hitch strong enough to push or pull vehicle at its heaviest weight. The hitch must have a 3 inch
12. Component tractors are permitted. All new component tractors must have approval of sheetmetal and engine combination from
the OTTPA Pro Stock tech committee and the executive
a: tractors must be 2wd or MFWD model tractors. No 4wd. Track model tractors allowed
b: tractors must have stock agricultural type block, OEM replacement block or its replica. A replica to be considered must
retain stock bore spacing and operate with the stock crankshaft for the model without any alterations for chassis mounting
c: engine blocks and clutch housings must remain in original position from center line of the rear axle to rear face of the block, not
to exceed 60 inches; even if OEM model is farther forward than 60 inches, ie: new style John Deere
d: engine block must be mounted solid to full frame at both front and rear
e: the centerline of the crankshafts nose can be no lower than 4 inches below the centerline of the rear axle
f: maximum wheelbase is 114 inches
g: aftermarket frame must have a SFI 6.2 or 6.3 bellhousing. No cast iron Ag type transmission or rear end components allowed
h: all lenco type planetary transmission excluding reverser must be with an approved blanket. All driveline must be enclosed with
5/16 inch minimum steel or 3/8 inch aluminum round inside diameter not to exceed 2 inches more than outside diameter of the
largest universal joint fastened every 6 inches or closer, with 3/8 inch or larger bolts, grade # 5 or butt and seam welded and
securely mounted to vehicle frame. No more than 1/4 inch of end of driveline shall be visible with driveline shielding in place
13. Skid plates (Mandatory for 2017). Skid plate must be mounted in line with each frame rail and extend from the center of the front
axle forward (on both sides) equal in strength to frame rail material. Skid must be securely mounted and braced to the chassis. Skid plate
surface to be minimum of 4 inches wide and 12 inches long with a minimum of 6 inch curve when measured from the front most part of
rolled edge. Note: Skid plate must be able to support the weight of the front end when checked with a jack. Maximum ground clearance is
bottom of wheel rim not to exceed 4 inches with front tires in normal opening position.
1. Maximum tire width 7000 lb / 7500 lb - 30.5" must be ag tires 24.5" are allowed HP's or Puller 2000's
9000, 10000, - 30.5"
1. The maximum drawbar height is 20 inches from the top of the hitching device (point of hook) to the ground. (see general rules
2. Minimum drawbar length is 18 inches from center of the rear wheel to the point of hook, measured horizontally
1. Roll cages to be built to good welding standards with a minimum of 3 bars of 2 inches, 120 wall thickness with inspection holes.
Roll cages must be constructed to be able to support the weight of the tractor
2. Roll cages must be equipped with a high back seat and a 5 point seat restraint
1. All tractors must have a working deadman throttle
2. Tractor must have automatic kill switch and/or air intake shutoff (diesel). The hook ring must be located in the center rear of
the tractor, a minimum of three feet above point of hook. The kill switch must be no less than 2 inches in diameter. Diesel
tractors must have mechanical fuel shutoff to the injection pump
3. Tractors must have an up to date SFI 4.2 approved blanket or SFI 6.2 bellhousing covering clutch and flywheel. Blankets must be at
least seventeen (17) inches wide and long enough around the bellhousing with six (6) inches of overlap, secured with a two (2)
inch wide nylon web strap of steel "D" rings on one end and sewn the length of the blanket, except the overlap area and long
enough to pass back through the "D" and to be tied in a saddle cinch. The blanket must have four (4) two inch nylon web retaining
strips, each at the front and back of the blanket. Blankets must pass regular tech inspection.
4. Tractor must have a safety stating device, tractor is only able to start in neutral and/or park
5. Tractors must have a working fire extinguisher (2 lb ABC, 1 lb halon) convenient to driver
6. Tractors must have an automotive type white light on the dashboard and one within 6 inches of the kill switch or air shutoff to
indicate when the vehicle is in reverse
7. Drivers must wear a CSA approved helmet and seatbelt(s) Driver must wear a fire suit. If alcohol fuel is used driver must wear
a minimum single layer fire suit, balaclava, fire gloves fire boots, or leather boots. No leather running shows allowed.
1. A light pro stock tractor may move up into the 9000 lb class provided the heavy prostock tractors have two classes offered at
2. A light pro stock tractor may also compete in the 9000 lb class if the light class is not offered.