I-88 Speedway Modified Engine Rules

The Modified engine rules for I-88 Speedway are listed on this page.

Forms: [Driver Sponsor Sheet] [I-88 Speedway License]


[BIG BLOCK-BIG SMALL BLOCK (OVER 358 CI) ENGINE SPECIFICATIONS] [Engine] [Carburetor] [Intake Manifold] [Cylinder Heads] [Camshaft] [Pistons / Rods / Crankshaft] [Ignition] [Lubrication] [Fuel]

Page 2 of Rules: [Go to Page 2] Includes 358 Modified Engine Specifications: Engine, Blocks, Cylinder Heads, Crankshaft, Rods, Pistons, Vibration Dampners, Camshaft, Intake Manifold, Carburetor, Ignition, Lubrication System and Fuel

[PDF of Modified Engine Rules] [Download Adobe Acrobat]


(I-88 Speedway allows various engine combinations. This is a guideline for the more popular).


  1. Only stock OEM American long block (in length) manufactured V-8 engines (GM, Ford, or Chrysler) are permitted.
  2. Aftermarket Dart and Merlin cast iron blocks are permitted.
  3. No aluminum blocks are permitted.
  4. Only normally aspirated engines are permitted.
  5. Maximum displacement of 467 cu. in. 396 cu. in will be the minimum displacement permitted! A 10 cubic inch max. limit will be allowed for wear.
  6. No reverse rotation engines.

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  1. Engine limited to one four barrel carburetor from an established American carburetor manufacturer. A manufacturer, is defined as a builder that produces a minimum of 600 units per year.
  2. Carburetor not to exceed 4 venturies, 650 or 750 maximum on small blocks over 361 ci and must pass no go gauge.
  3. No fuel injection, no nitrous oxide injection, no turbo chargers, or superchargers are permitted.
  4. Holley hp carbs allowed.
  5. No fuel or air may enter by any means other than stock operation of the carburetor.
  6. No in-line venturi carburetors.

Intake Manifold:

  1. Optional as to design or manufacturer, but the manifold must allow for the mounting of only one 4 barrel carburetor.
  2. Must be cast iron or cast aluminum only.
  3. Porting is permitted.

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Cylinder Heads:

  1. Optional as to design or manufacturer but must be made of cast aluminum or cast iron only.
  2. Any form of porting is permitted.
  3. Valve sizes are optional.
  4. Titanium valves and retainers are permitted.
  5. No hollow stem valves or liquid cooled valves are permitted.
  6. Only 2 valves per cylinder are permitted.
  7. Only one spark plug per cylinder.


  1. Optional as to design or manufacturer but camshaft must be in block in stock location.
  2. Chain or belt drives are permitted.
  3. No overhead cams are permitted.

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Pistons / Rods / Crankshaft:

  1. Only aluminum pistons, with no coatings of any kind are permitted.
  2. Any steel or cast iron crankshaft is permitted.
  3. Any design, length, or make of steel rods are permitted.
  4. No titanium crankshafts or rods are permitted.


  1. Any kind of ignition is permitted, as long as it is mechanically driven in the stock position.
  2. No crank trigger ignition systems are permitted.
  3. Only one ignition coil and one ignition box (amplifier) are permitted on the car.
  4. Only one spark plug per cylinder is permitted.
  5. Traction control devices are not permitted. Traction control devises that use the brakes are also illegal.
  6. Ignition boxes must remain as manufactured with no internal or external alterations. NOTE: Ignition boxes may be swapped or confiscated by Speedway at any time.
  7. Wiring must remain as designed by box manufacturer.

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Lubrication System:

  1. Conventional or dry sump may be used.
  2. An internal or external pump is permitted.
  3. Oil coolers are optional.
  4. Only one oil tank and one oil cooler are permitted! Oil pan must be made from steel or aluminum only.
  5. Air pumps / vacuum pumps that suck air from the oil pan are not permitted. Oil pan must have a 1" plug on the left side to allow for verification of steel crankshaft and rods.
  6. Oil pans will be pulled down only when protested or in the absence of the 1" plug.
  7. The oil tank and the oil cooler may be mounted outside the frame rails.
  8. Oil tank maximum capacity not to exceed 12 US quarts.
  9. Tank and cooler must be fully enclosed by the body and must be securely mounted. See cooler location in minimum specification rules. Excessive bracing used for mounting these items to obtain more left side weight is subject to the discretion of the track inspector.


  1. Only racing fuel or pump gas is permitted.
  2. No nitrous or any other additives are permitted.
  3. All fuels are subject to random testing at each track.
  4. No electric fuel pumps are permitted.

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