Afton Motorsports Park Crate Sportsman Rules

The Crate Sportsman rules for Afton Motorsports Park are listed on this page.

Forms: [Driver Sponsor Sheet]


Page 1 of Rules: Go to Page 1 of Rules, includes Engines, Carburetor/Air Cleaner, Ignition/Rev Box
Page 2 of Rules: [Exhaust/Muffler Systems] [Oil Cooler/Oiling Systems/Engine Cooling] [Driveshaft/Rear End/Axles] [Front End] [Shocks/Springs/Suspension] [Fuel] [Fuel Cells] [Bodys/Bumpers] [Wheelbase/Tread Width] [Wheels/Tires] [Weights/Wheel Combinations]
Page 3 of Rules: Go to Page 3 of Rules, Includes Protests, Penalties and Fines, Conclusion.

[PDF of Crate Sportsman Rules] [Download Adobe Acrobat]

Exhaust/Muffler Systems

  1. Any steel exhaust header is permitted, but can't exceed 1 5/8" inches in outside diameter from the head flange to the collector. No Tri-Y, stepped, ceramic, coated, or stainless steel headers and/or collectors permitted.
  2. Must have just one noise reduction muffler per side. Suggested mufflers (but not mandatory) include Dynomax (part# 17223 or 17296), Extreme (part# 31530 or 31230), or Beyea (part# MUF3DM). Other mufflers such as Henry's Stainless Steel are legal.
  3. The GM 602 Crate Engine comes with factory seals. The factory seals must remain in place unaltered and as originally manufactured. Factory GM seals should not be tampered, modified, or removed. The crate engine comes this way for a reason and should not be altered in any way.
  4. Header collector extension pipe, tail pipe, curves, and tips, may be stainless steel (Henry's Stainless Steel Exhaust) and exit the racecar past the driver and rear tires.

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Oil Cooler/Oiling Systems/Engine Cooling

  1. The GM 602 Crate Engine comes with break off sealed bolts on the oil pan. In the event they need to be removed due to repair/damage where the repair is LESS than overall replacement the following rules apply. Only one single wet sump oil pump is allowed. Only stock steel replacement oil pans should be in place, if needed to be replaced only OEM Stock GM performance 602 Crate Motor replacement pan may be used.
  2. Dry sump oil systems, external type oil pumps, vacuum pumps, and accu sumps are not allowed. Engine evacuation systems by either internal or external driven pumps by exhaust system or valve covers, intake manifold, or oil pan are not allowed.
  3. Oil coolers are permitted.
  4. Only cast iron water pumps are allowed.
  5. Only one brass and/or aluminum radiator is permitted.
  6. Cooling fan for the radiator must be mounted in the stock OEM location on the front of the cast iron water pump. No mounting the fan to the crankshaft is permitted. Electric water pumps or cooling fans are not allowed.

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Driveshaft/Rear End/Axles

  1. Only steel magnetic drive shafts are legal. No titanium or aluminum drive shafts are permitted. Only steel drive shaft yokes or driveline components are legal. ABSOLUTELY no titanium or aluminum drive shafts, yokes, or components are permitted.
  2. Competition type manufactured quick-change 8 bolt, wide 5, or smart tube style rear ends only. Live rear ends with aluminum or steel tubes are permitted. No open tube rears are permitted. Only full size competition manufactured type rear ends are permitted meaning no miniature rear end housings are allowed. All rear end components, ring & pinion, gears, and any other components must be specific in size to the rear end manufacturer. A minimum of 8" inch diameter ring gear is permitted and mandatory.
  3. Titanium axles are NOT legal or permitted. Any other titanium drive shaft, rear end, axles, or components of the rear are not permitted.
  4. No limited slip rear ends, locker rear ends, slip hubs, or ratcheting drive flanges are allowed.

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Front End

  1. Only strait one-piece steel tubing from axle with no camber adjustments permitted. No split axles or drop axles allowed.
  2. All brackets on the front axle must be bolted or welded solid. No birdcages or sliders allowed on the front axle. Kingpin type axles only.

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Suggested Types of Legal Shocks.
(Pictures do not include all brands and makes)
Crate Sportsman Suspension image
Click Image for larger version.

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  1. Absolutely no oxygenated fuels permitted.
  2. Sunoco 110 and/or 112 and/or max 94-octane pump fuel is permitted. No mixing of fuels with different octane.
  3. No methanol, alcohol, nitrous oxide, nitro-methane, or propylene oxide fuels are permitted or legal. Fuel may be subject to inspection and/or testing at ANY time.
  4. Afton Motorsports Park racers MUST display the official Sunoco decals to be eligible for point monies and giveaways.

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Fuel Cells

  1. A racing fuel cell is mandatory with a maximum fuel volume of 24.5 gallons.
  2. Fuel cell must be a minimum of 12quot; inches from the ground and be centered in the frame rails. No offsetting.
  3. The fuel cell must be completely enclosed in a steel fuel cell container with a minimum gauge of 20.
  4. Aluminum fuel cell containers are also allowed, but must be at least .060" minimum thickness.
  5. The fuel cell must be fully foamed inside with a minimal cut out for the filler.
  6. Fuel cell must be mounted securely by at least 2 steel straps.

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  1. Traditional Sportsman body rules in effect. No exotic large doors or window panels permitted. Please use the DIRTcar Sportsman body rules for guidelines if unaware what is or is not legal.
  2. Traditional bumpers/rub rails in effect. Bicknell, Teo, HigFab, etc. all make bumpers/rub rails along with speed shops. Utilize their products. No exotic or outrageous bumpers/rub rails permitted. (Afton Motorsports Park officials reserve the right to reject any body and/or bumper/rub rail deemed above and beyond normal.)

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Wheelbase/Tread Width

  1. Front-end width (tread width) must be minimum 74" inches with a maximum of 86" inches measured from the outside edge of the sidewall of tires on each side.
  2. Rear-end width (tread width) must be minimum 74" inches with a maximum of 86" inches measured from the outside of the sidewall of tires on each side.
  3. Wheelbase must be a minimum of 106" inches with a maximum of 110" inches measured from the tire wall at center hub location with a ½" tolerance.

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  1. Any Sportsman/Modified type American Racer tire is legal. NO late model tires, no block pattern tires, no 49 AR compound.
  2. Steel wheels will be given a 100lb weight break, while aluminum wheels are legal with no weight break
  3. No left rear on the right rear or left rear on the right front etc.
  4. Chemical alteration of any tire is not legal or permitted. Tire siping, grooving, or grinding is permitted. Tires can be subject for inspection/testing at ANY time.
  5. Heating the tires by torch, heating blanket, or any heating devices is not permitted.

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Weights/Wheel Combinations

  1. Aluminum Wheels - GM 602 Crate Engine cars running Aluminum wheels must weigh a MINIMUM of 2400 lbs.
  2. Steel Wheels - GM 602 Crate Engine cars running Steel wheels must weigh a MINIMUM of 2300 lbs.
  3. No mixing and matching wheels for weight. No putting one steel wheel with 3 aluminum wheels to weigh steel wheel weight. If the situation comes about there is no option but to mix, you will automatically be required to weigh the 2400 lbs. Suggestion to borrow another aluminum wheel.
  4. KEEP IN MIND all track scales are official. Make sure weight is made at each track's scale.

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