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Clone Class Rules

We will follow AKRA "Box Stock Clone" Engine rules for all clone classes

Pipe and clutch rules have been modified per track discression.

These classes are "NOT" a builders prepared class (BP engines will be deemed illegal).

  •     Approved Engines: OHV (Overhead valve) engines commonly known as clones. The engines are limited to a maximum displacement of 196cc. Currently the legal engines include, but are not lmited to the following manufactures: Lifan Greyhound (old blue harbor freight providing the cylinder head is replaced with the 4 bolt valve cover JT or TG-1 cylinder head). Blue MAX.

                                                           NO PREDATORS 

  •     Classes:

            Purple Clone (ages 7-12) 250 weight. Must run .500" Purple restrictor (Full rear bumper mandatory)​

            Blue Clone (ages 12-15) 300 weight. Must run .550" Blue restrictor

            Senior Clone 350 (ages 15 and up) 350 weight. No restrictor.

            Senior Clone 400 (ages 15 and up) 400 Weight (Driver must weight 200 in gear). No restrictor

               *Note that the track has the right to make exceptions to what class a junior driver may race in                      based on age and/or experience for the safety of that driver as well as other competitors. Age                      limits must remain intact. If you plan to move your child up out of their age group, you MUST get                  track approval. Once you move up you can not go back down.

  •     Engine Components:  Must be original OEM clone components unless otherwise specified. You may remove unnecessary OEM items such as stock exhaust, air cleaner, fuel tank, governor, low oil sensor etc. 


  •    Headers and Mufflers: All Jr clone classes are required to run small "weenie" pipe only with approved RLV Spec Mini Muffler. Sr clone classes are permitted to run the choice of "weenie" pipe or big pipe with RLV BL-91 muffler. No loop pipes or custom pipes. All pipes must meet AKRA length and size requirements found in the AKRA tech manual. Exhaust pipe MAY NOT PROTRUDE inside of the exhaust port. All headers, including "weenie" pipes must be securely wrapped/sleeved from mounting flange to wrapping/sleeving allowed on silencer.

  •     Fuel: 87 octane gasoline only. No additives allowed. No methanol (alky).

  •     Carburetor: Huayi, Ruxing, or Tillotson PK-1 type carb only. Choke assembly must be in place and functional. Blueprinted carbs are permitted providing they are blueprinted for box stock clone class. Venturi .615" max diameter and round checked with a go/no-go gauge .751" max rear bore. .750"max depth to ridge behind butterfly. No dimpling or swirl cutting venturi or carb bore. Jetting in non tech. No grinding of emulsion tubes. The minimum protrusion of the e-tube into the Venturi must be checked with No-Go gauge (Huayi .488", Ruxing .479", Tillotson .488") They must appear as stock and meet AKRA requirements (2 or 4 hole max). Aftermarket filter and filter adapter are permitted. Any pulse type fuel pump is permitted and may be pulsed from the crankcase, side cover, or valve cover. Carburetor dimensions to be checked with go/no-go gauge. Plastic isolator must be installed in its original location and may be blueprinted to AKRA specs (.265" minimum thickness across gasket mating surfaces and no angle cutting of the surface). In other words no attempt can be made to redirect the flow. Mounting holes may not exceed .300".

  •     Head: TG-1 or JT castings only. (4 bolt valve cover heads) Large chamber (22'cc's). High compression 14cc heads are not permitted. The heads may have 3 angles on the valve seats. 45​ degree face angle, 30 degree top relief, and 60 degree bottom relief. .899 max intake seat I.D. Stock valve sizes only. Intake valve .982" max. O.D. Exhaust valve .945" max. O.D. You may run the shorter valve stock configuration to meet the .815" installed height rule. 10.8 lb. @ .850" height and max tension of 18 lbs @ .650" height valve springs only, max wire dia .071" minimum installed height .815" checked with no-go gauge. Shims may be used to meet this requirement providing they do not exceed .075" thickness total including valve seal lip. Verify that the spring ends are parallel to each other (procedure to check for parallel ends... using dial calipers, check overall length of spring, then rotate spring 180 degrees and check overall length again, 180 degrees from original check ... the two checks can not vary by more than .015". Each  spring is to be checked using a .750" height by .800" width plate gauge and a .250" (square) NO-GO gauge to check the center spacing of the coil springs while inserted into the plate gauge). Prescribed check procedure as follows - insert the spring in the .750" x .800" plate gauge (spring must be centered in the plate gauge and must fit inside of the gauge with the ends of the spring wires perpendicular to the plate). Once inserted in the plate gauge take the .250" NO-GO and check the center coil spacing on both sides. The .250" NO-GO gauge must be parallel to the spring wire and perpendicular to the center of the spring when checking. The .250" NO-GO must pass check on at least one side of the spring. If the .250" does not enter either, the spring is deemed illegal. NOTE: the .250" pin is to be used on one side and then the other side. At no time is the .250" pin to be slid through the block to touch the coil on the opposite side. This check is to be performed after the 10.85 lb, 18 lb check, and .071 max wire diameter check have been performed. Ends of the valve springs may be sanded to help meet spring checks. Springs MUST PASS both checks (Dead weight & Spring Box) if available. No sinking the valves below the deck of the chamber. Head must remain stock geometry no valve angle changes or angle milling. Head may be resurfaced to meet the AKRA CC rule of 26.5cc. Head gasket is a non teck item. Porting is permitted however both intake and exhaust ports must meet the following guidelines.  NO-GO's for the intake opening vertical (flat to oval sides) .962" ... NO-GO horizontal (flat to flat sides) .950" and exhaust exit vertical (flat to oval sides) .974" ... NO-GO horizontal (flat to flat sides) .967". Both ports must retain their original D shape design. No visual tech on surface finish, no adding of material, cannot touch the seat or valve guide in the porting process, and no rifiling or dimpling of the port area. Valve guide length: 1.055" (new gauge will check proper length s well as guide location or depth into porting area) also checks spring pocket flatness, stock guidelines only.

  •    Camshafts: Stock or aftermarket camshafts are allowed providing they meet the following AKRA box stock clone requirements. Ez-spin assembly must remain as stock. Cam lobe base circle diameter .865"  - .005"/+.010" Duration check for intake and exhaust lobes (taken off push rod). Intake duration of 218.5 degrees at .050 lift/85.5 degrees at .200 lift. Exhaust duration of 221.5 degrees at .050" lift/96.5 degrees at .200" lift. All checks will allow +2/-5 degrees for wear and gauge variances. Max intake lift on .200" lift - Min .215" lift taken at the push rod. Max intake lift at the valve .238" Taken on valve spring retainer as raced. Max exhaust lift on cam .232" - Min .222" lift taken at the push rod. Max exhaust lift at the valve .242" Taken on valve spring retainer as raced.

  •    Valve Train: Box stock lifters only, no modifications allowed. Over-all length of push rod 5.285" max, 5.230" min. Push rod must be of 3 piece design (hollow or solid tube with 2 solid ball ends). Lifter head diameter .915" min with no visible modifications. Factory 1:1 rocker arms only. No roller rockers. Rockers may be ground at tips to meet running lift requirements.

  •   Block: 2.691" Max bore (approx .010" over). Oil return hole not to exceed .215". Stock crank bearings only (no ceramics bearings permitted). Re-sleeving block in not permitted. No piston pop-up allowed. Governor hole may be plugged. Block to head mating surface may be machined to correct cc's or correct gasket failure.

  •   Crankshaft: Stock box stock crankshaft required. Machining, polishing, addition of material or other alterations of crankshaft is prohibited. Stock factory timing gear mandatory and must be installed in original location. Crankshaft journal diameter is 1.180" max - 1.168" min. Crankshaft stroke is 2.123" +/- .010.

  •   Connection rod: Stock connecting rod required. The pressure casting performance rod is also permitted. Oil hole size .179" max. 2.375" max length 2.350" min length. NO BILLET RODS ALLOWED.

  •   Piston: Must be unaltered box stock dished piston only. No machining of pistons or rings allowed. File fitting is permitted. No aftermarket flat top pistons.Piston must be of a 3 ring design and all rings must be intact and functional. Maximum oversize .010" (see block section).

  •   Flywheel and Ignition: Must use stock clone ignition coil, plug wire, and resistor spark plug boot. Spark plug is non tech. Stock flywheels are prohibited. Must use billet flywheel for safety reasons. Flywheel must be from approved list, 3.3 lb minimum weight. No flywheel modifications allowed. The following flywheels are allowed: ARC 6618, 6619, King billet steel, Raceseng REV WHEEL - finned-S-1, Billet aluminum Slipstream, and Dyno PVL aluminum flywheel.

  •   Starter: Electric starter with starter nut permitted. May also use recoil pull start. Pull starter may be rotated for better cranking angle and have better quality replacement rope installed.

  •   Clutch: All Jr plate clones must run a drum clutch only. Sr clone classes may run drum or disk clutch of choice.

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