2.0 Engine Requirements
Only "small block" cast iron V8 engines with a minimum displacement of 350 cubic inch will be allowed for competition. No aluminum engine blocks allowed.
Note: The track reserves the right to inspect any engine for adherence to these rules at anytime, engines may be whistled and P&G tested at random.
2.1 Engine Blocks (Chevrolet or Dart)
- Comp Series Dart little (M) No. 31131111
- Bowtie cast iron blocks 10051183, 10185047
- Standard production block is also allowed.
- Engine displacement may be increased by boring. Formula for determining cubic inch displacement: Bore x Bore x .7854 x Stroke equals cubic inch displacement of each cylinder. The cubic inch displacement of each cylinder added together will determine the total cubic inch displacement of the engine.
- Maximum bore size of 4.00 to 4.060 plus or minus .005” (inch) tolerance permitted.
2.2 Cylinder Heads
- The following 23 degree un-ported heads are approved for competition:
- GM Cast Bowtie Heads -#14011034
- GM Cast Bowtie Heads -#14011058
- GM Cast Bowtie Heads -#12480034
- Dart Platinum - #10310010P
- Porting and polishing by the removal or grinding of the original casting in runners is permitted.
- No Epoxy fillers, welding, spray welding or any other coating or materials on or in heads.
- External painting of head to match engine is permitted.
- No acid porting, dipping or etching of any kind, violation of this rule will in disqualification and loss of all winnings for that event. The team will also be stripped of all season points and may be banned from competition at the discretion of Shangri-La II Speedway Management.
- The maximum compression limit allowed shall be 12.0 to 1 on any cylinder.
- When calculating the compression ratio, an allowance of one (1) cubic centimeter will be added to the volume for the area around the top of the piston down to the top of the piston ring that will be sealed with grease. * The procedure for checking compression is as follows: Bore x Bore X .7854 x Stroke equals the Cylinder Volume of each cylinder at Bottom Dead Center (bdc) in cubic centimeters. The cylinder head pour volume minus(-) the known volume of the cylinder head plate plus (+) head gasket volume plus (+) 1.00 cc for sealing piston ring plus (+) the cylinder block volume minus(-) the known volume of the block plate equals(=) chamber volume. (Compression ratio = Cylinder Volume plus (+) Chamber Volume)
- No repositioning of head on block. Stock location only.
- All bolt holes and bores must remain in stock OEM location.
- No Angle cutting of Block Deck will be permitted.
- Any attempt to alter, change, or eliminate part numbers will result in that part’s ineligibility.
2.3 Valves & Springs
- Valve springs of any type may be used, springs must be made of magnetic steel.
- Titanium valve spring retainers and keepers are permitted.
- Multiple angle valve job must maintain valve centerline and guide angle in OEM stock location in relationship to the head.
- No air directional devices on any valve surface.
2.4 Maximum Valve size Specifications:
- Maximum valve size measured at the face of the valve is 2.050” (inches) Intake, 1.600” (inches) Exhaust.
2.5 Push Rods
- Push rods must be magnetic steel only.
2.6 Rocker Arms
- Any type Roller Rocker arms are allowed.
- Shaft mounted rockers are allowed.
2.7 Stud Girdles
- Stud Girdles are allowed.
2.8 Pistons, Rods, Cams, Crankshaft
- Solid Steel connecting rods required, no titanium, aluminum, stainless steel or other material allowed in or on connecting rods.
- The maximum connecting rod length allowed is 6.000” (inches).
- Any flat top, dished or dome round aluminum piston permitted. Valve relief may be cut into piston.
- Pistons may not exceed engine compression rule.
- All pistons must utilize the mandatory three (3) rings only.
- No ceramic, plastics or any other materials on or in pistons (aluminum only).
- Cam and lifter bores must be in original OEM location.
- Steel lifters only, Solid or Hydraulic with roller tappets or mushroom tapers only.
- Rev kits are permitted.
- Roller camshaft bearings are permitted.
- Standard steel magnetic production design crankshaft only.
- Minimum of 48 lbs with 2.100 rod journal 2.448 main journal.
- Undersizing of crank journals permitted to .040 providing rod bore is 2.225.
- Crankshaft. Stock Stroke 3.480 with a tolerance of +.005 / - .010 is required.
- Counterweights must be same shape as original OEM Mass production crankshaft used with the block.
- Leading and trailing edges of counterweights may be round nosed or Knife edged only.
- Outside diameter of counter weights may be drilled or machined or ground for balancing.
- No undercut or tapered counterweights. Counterweights must be same width from main and rod journals to outside diameter of counterweight.
- Mains & Rod journals may be drilled.
2.10 Timing Chain
- Any timing chain and gears may be used. Degree bushing and offset crank gear keys may be used.
- No gear drives or belt drives permitted.
2.11 Vibration Damper
- Stock-type steel or cast iron. Dampers may not to be machined or altered in any way.
- Harmonic balancer minimum diameter 6.25” (inches). Fluid dampener is legal.
2.12 Oiling System
- Dry sump oil systems are recommended.
- No oil, tanks or lines allowed in drivers compartment.
- Maximum number of stages for Dry Sump Pumps is 5.
- Maximum dry sump pump length is 10” (inches) x 3 1/2” (inches) across.
- No oil deflecting of individual rod or main journals.
- Oil coolers allowed, if mounted above interior sheet metal must be no larger than 5” (inches) in height by 10” (inches) wide.
- Outside edges of oil cooler must be sealed with sheet metal.
- No partition in oil pan of any kind.
- All oil pans are subject to approval by the Shangri-La II Tech Officials.
- A 1” (inch) inspection plug must be placed in bottom of oil pan for inspection.
2.13 Intake Manifolds
- The following manifolds are approved for use:
- Brodix Part Number: HV 1000
- Edelbrock Part numbers: 2975 / 2999 / 2925 / 2926
- Chevrolet Bowtie Part Numbers: 2972 / 2996
- Weiland Team G Part Numbers: 7530 / 7532
- Holly Part Number: 300-25
- GM Part Numbers: 10051102 / 10093374
- HVH Part Number: 10003
- DART Part Number: 42411000
- Intake manifold maybe ported.
- No welding or epoxy fillers allowed.
- The intake manifold may not be painted or coated inside or outside.
- Intake manifold gasket maximum thickness is .125.
- No Spacers allowed between intake manifold and heads.
- Carburetor is limited to one (1) Stock Holley 4777 650 CFM only.
- No internal or external modification allowed carburetor must remain stock.
- Changing power valve accelerator pump and jets is allowed but must be same as OEM.
- Choke plate and horn may be removed. Gasket ring area must remain stock.
- Boosters must be stock size and location but can be aligned.
- Carburetor must pass all Shangri-La II Speedway gauge checks to be eligible for competition.
2.15 Carburetor Spacer and Gaskets
- Only a 1 piece carburetor spacer, maximum 2” (inch) in thickness may be installed between the intake manifold and the carburetor on steel headed engines
- No alterations allowed to carburetor spacer.
- The top (carb side) and the bottom (manifold side) must be parallel, No wedge shape allowed. Port Holes must be vertical top to bottom (90 Degrees). No beveling, tapering, grooving, flaring, or radiusing of port holes. Spacer may not be stepped or undercut.
- Port Holes must be the same size and shape at the top and bottom and must pass through the entire spacer adapter with no additional holes or channels that will allow air to enter the engine.
- Spacer must position carburetor over original mounting position on intake manifold.
- Only 2 paper gaskets (1 per side) with a maximum thickness of 0.065” (inch) will be permitted. Gaskets may be altered to match carburetor base openings.
2.16 Carburetor Jets
- Carburetor jets must be the same type as supplied by the carburetor manufacturer.
2.17 Carburetor Air Filter
- Round dry type air filter with a diameter of between 12” (inches) to 14” (inches) and between 1 1/2" (inches) to 5” (inches) in height.
- Top and bottom of the air cleaner housing must be round and solid with the exception of the carburetor opening.
- All air must be filtered through the air cleaner element.
- No devices of any kind that will direct or duct air to or from filter.
- Filter must be centered on the carburetor.
- It will be permissible to shield the front area of the air cleaner up to a maximum of one-half of the air cleaner circumference and no wider than the height of the element.
- No performance enhancing additives or chemical on or in air cleaner or anywhere else.