Predator Engine Rule Book

Predator Engine Rules

Core Rule

• All Predator engines must be run “out of the box” with the original factory parts.
• Any modification to stock parts or changing the original parts will result in fines and suspensions.
• All engines will be compared to a known stock engine for tech.

Carburetor

SP Carburetor Jet Sizes

• Idle jet: max size .014 (.015 gauge must not pass)
• Main jet: max size .030 (.031 gauge must not pass)

Hyuai Carburetor Jet Sizes

• Rules are forthcoming. These carbs generally feature a larger idle jet and a smaller main jet than the SP carb.
• Idle jet: max size .017
• Main jet: max size .028

Camshaft Lift

• Intake: .223 ± .005
• Exhaust: .228 ± .005

Exhaust System

• There are 3 holes inside the port-side of the exhaust pipe; these holes must be uniform and present.
• Any machining or opening of these holes is prohibited.
• The additional perforated holes located on the screen side must be unaltered.
• This will be compared to a known stock system.

Block & Head

• Hemi head depth: .420+
• Engine stroke: 2.164 (+.005)
• Engine bore: 2.755 (+.008)
• Spark plugs must be single-probe style.
• No flat racing plugs.
• Washers are allowed.

Air Filter & Box

• Must be installed per factory specs.
• Loose or missing wing nut on air filter will result in disqualification.
• Foam pre-filter must be installed.

Fuel Rules

• Pump 87 octane fuel only.
• Must be fresh; old fuel may fail testing.
• Samples may be pulled from tanks and placed into approved containers.

$100 Fine Violations & 50 Point Penalty

• Modified or incorrect carburetor jetting
• Modified air box
• Modified exhaust system:
• interior holes
• baffles modified

$300 Fine & 300 Point Penalty

• Hemi head depth less than .420
• Engine stroke exceeds 2.164 (+.005)
• Engine bore exceeds 2.755 (+.008)

Camshaft Rule

• The stock camshaft must remain unaltered and original to the engine as it came from the manufacturer.
• Changing or replacing the stock camshaft with any other camshaft, regardless of brand, lift, or intent, results in a $300 fine.

Oil Test

• Oil introduced to a flame must not ignite.
• Flammable oil results in a 1-race suspension + $300 fine.

Loud Exhaust

• Loud exhaust pipes may result in a disqualified lap or full-event DQ.

Sealing & Protests

• The series may install red seals on engines that have passed post-race tech.
• These seals must remain on the engine for the duration of the season.
• Once the season concludes, seals may be removed.

Protest Procedure

• Engines may be protested for $100.
• The protesting party may choose one specific area to inspect.
• The winner of the protest receives the protest fee.

Additional Tech & Operation Requirements

• Engine must remain stock, with no signs of tampering (examples given: dry graphite, Scotch-Brite marks, scratches).
• Flywheel must retain the factory-installed keyway.
• Governor test limit: 5,500 RPM max with tires installed.
• Engine must fully surge by 5,500 RPM.

Surge Test Attempts

A total of three attempts will be made to confirm surge:

1. Initial test
2. Turn engine off/on and retest
3. Final attempt

If no surge is heard and the engine isn’t close to surging, further testing may be stopped.

Double Feature Nights

• A 5-minute cool-down period will be provided before RPM re-checks for the second feature only.

Allowed Adjustments & Exceptions

• Vent hose may be disconnected at the fuel tank (must remain attached to air box)
• Valve covers may be sealed with silicone instead of gaskets
• Throttle stop screw may be removed
• Factory fuel tank must be used
• Pull cord may be taped
• Air can be directed to the engine using hoses or fans
• No aftermarket parts, except chain guard
• Oil sensor wire may be disconnected
• One engine may be claimed per year for $160
• Gas cap may be vented
• Supplied spec engines may not be claimed
• A driver can only be claimed once per season

DNQ Sealed Engine Program (Ghost and Predator 212cc)

• Engines sealed by DNQ will cost $100 over market price and are not eligible for claim.
• Engines are sealed and documented by the series.
• A digital PDF will be provided, including:
• pictures
• seal numbers
• serial numbers
• The DNQ Series keeps a database of all sealed engines.
• If seals are damaged, the series must be notified immediately.
• The engine will be inspected before re-sealing.
• Any tampering results in a $1,000 fine and a one-year suspension.
• Seals will be applied to (but not limited to):
• head
• exhaust
• air box
• side cover
• valve cover
• The series may cut seals for tech.
• After inspection, the engine will be re-sealed either at the track or returned for reprocessing.
• If you purchase a sealed engine from another competitor, contact the series to verify the seals.
• Reminder: any tampering or attempt to re-seal a DNQ-sealed engine results in a $1,000 fine and a one-year suspension.