SECTION 10 – TECHNICAL RULES BY DIVISION
10.1 KART CHASSIS SPECIFICATIONS:
10.1.A 2012 WKA Speedway Dirt Series chassis specs as listed in the WKA 2012 Tech Manual should be used as a guideline. Any
specific rules listed in the 2012 DH2 rules take precedence over WKA rules. In the event of a rule conflict, DH2 officials reserve the right to make the
decision as to whether to impose penalty, request that the part be changed to comply with our interpretation, or to allow the part. In such a case
where a conflict may occur, a clarification will be announced on the track website and in the next drivers meeting. 2012 WKA Tech Manuals are
available from WKA, MEI Smallcar, JC Specialty, or other similar suppliers.
10.1.B TIRES: Must be Burris Dirt Slicks. Any series or compound is acceptable. NO grooving or siping. Grooves from rubbing nerf bars, etc.,
or tires that were previously siped but have been worn to the point the sipes are barely evident will be allowed at the tech inspectors discretion. IT IS
HIGHLY RECOMMENDED IF YOU HAVE SUCH A TIRE THAT YOU GET APPROVAL BEFORE RUNNING IT!
10.1.C BODY: Body may be either a junior or senior body, provided the driver has sufficient visibility when seated in the racing position.
10.1.D Quick release steering hubs may be used in all divisions. Hub may be of bolt on design or welded, and must securely fasten steering
wheel to shaft. Any hub not fastened in a manner acceptable to the tech inspector will require modification / replacement.
10.2 CAGED /CHAMP KART CHASSIS SPECIFICATIONS:
10.2.A All caged kart chassis must comply with the DH2 kart chassis specifications in section 10.1 with the exception that they must add a four
point cage and safety equipment as included in this section.
10.2.A.1 Caged karts must have a four point cage. Cage should be at least 3” above the top of the driver’s helmet when strapped in car. Main
cage must be constructed of tubing with a minimum outside diameter of 1”. Cage may be clamped to frame for easy removal, and should fasten to
frame just ahead of rear bumper and from a point falling from just behind front spindle centerline to the front of the frame. Cage MUST be clamped
in front. May be clamped or use tubing slid over frame on rear. NO HEIMS may be used for mounting. NO flattening the front down tubes and
bolting to the front bumper tab unless a second tab is welded to the frame to form a support on BOTH sides of flattened down tube. Any other
mounting method must meet the approval of the tech inspector. Hoops must be connected front and rear. A single support bar should be run along
left side of cage. This bar should be a minimum of ¾” in diameter, and may have a ‘slip joint’, at least 3” long, on one end to allow chassis flex.
This bar may have a single “bed rail” type hoop on top of it for added protection. This side support must bend outward and follow near the body line
to allow sufficient room to prevent the drivers head from striking it in a crash. THIS BAR MAY NOT RUN STRAIGHT FROM THE FRONT HOOP TO
THE BACK HOOP AND MUST ALLOW SUFFICIENT HEAD CLEARANCE! Another support bar should be run across rear of cage, approximately
shoulder height. This bar should be a minimum of ¾” in diameter, and should be no more than 8” from rear of seat. Shoulder straps should mount
here. All tubing must have a minimum wall thickness of .065”. All corners must be bent. No 90 degree cut-and-welded corners. Cage must be
constructed of D.O.M. type steel minimum. NO CONDUIT! A headrest within a reasonable distance of the drivers helmet is highly recommended. A
second support bar may be installed on the right side if desired, must meet same requirements as the left side.
10.2.A.2 A racing approved 4 point harness must be used. Webbing must be a minimum of 1 7/8” wide and must be in good, non frayed
condition. Whether the condition or age of belts constitutes replacement is at the discretion of the tech inspector.
10.2.A.3 Arm restraints mandatory in all caged classes!
10.2.B ALL YOUTH AND SPORTMAN CAGED KART DIVISIONS MUST HAVE A LOOP STYLE REAR BUMPER THAT IS ROUNDED ON THE
ENDS. MAY NOT EXTEND PAST WHEEL EDGE, MUST COVER AT LEAST HALF OF THE REAR TIRE WIDTH.
10.2.C Champ karts will be permitted to run with all caged kart divisions. CHAMP KART CHASSIS MUST COMPLY WITH 2012 WKA CHAMP
KART REGULATIONS. We HIGHLY RECOMMEND, though not mandatory, retro-fitting a kart type nose and loop style rear bumper onto the chassis.
10.3.A BRIGGS RAPTOR 5HP ENGINE SPECIFICATIONS
10.3.A.1 Raptor 5HP (Flathead) engine rules will be enforced as written in the Briggs & Stratton Raptor 5hp Stock & General 4 Cycle Notes
sections of the 2012 WKA Tech Manual. We cannot print the WKA Rules due to copyright laws. Do not ask. Racers wishing to view them must
purchase a WKA 2012 Rule Book.
10.3.A.2 Youth divisions must run designated restrictor plate and weight as listed in the divisions section.
10.3.B BRIGGS ANIMAL ENGINE SPECIFICATIONS
10.3.B.1 Animal engine rules will be enforced as written in the Briggs & Stratton Stock Animal & General 4 Cycle Notes sections of the 2012 WKA
Tech Manual. We cannot print the WKA Rules due to copyright laws. Do not ask. Racers wishing to view them must purchase a WKA 2012 Rule
Book.
10.3.B.2 Youth divisions must run designated restrictor plate and weight as listed in the divisions section.
10.3.C WVMP SEALED CLONE ENGINE SPECIFICATIONS (SportsMEN, SportsKIDS, SuperSENIORS)
10.3.C.1 The intent of the DH2 sealed clone classes is to provide a low cost out “out of the box” engine package for the beginner or budget
minded kart racer. Because of the multiple clone engine manufacturers, the extensive variations in quality control among them, the influx of
aftermarket parts, and the costs beginning to arise through the purchasing of “builder prepared” engines, DH2 will continues the sealed engine
program as established by Wyalusing Valley Motorsports Park. The engines, all sales, repairs, and internal inspections are done by MEI Smallcar in
Wysox, PA (570-265-8974). They come as a race ready long block with no governor and no low oil sensor. The side covers, cylinder heads, and
flywheel covers are all sealed to prevent tampering. NO accessories are included, main jet is NOT drilled. This should ensure a level playing field
and a low cost option for the racers. The rules are very clear, and the penalties very stiff. IF YOU ARE NOT CAPABLE OF BUYING AN ENGINE AND
LEAVING IT ALONE, THE STOCK APPEARING CLASS IS FOR YOU! ONLY ENGINES SEALED AND SOLD BY MEI SMALLCAR (WVMP OR DH2)
ARE ALLOWED! ENGINES FROM ANY OTHER SUPPLIER, SEALED OR NOT, WILL BE IMMEDIATELLY DISQUALIFIED!
10.3.C.2 Engine cost: The 2012 DH2 sealed engines are available from MEI Smallcar. The price for the base engine, sealed, is $159 ($150 +
$9 tax). A complete, race ready engine is $424 ($400 + $24 tax) (includes chain guard, air filter adapter, air filter, pre-filter, fuel pump, top plate,
throttle linkage, header/RLV muffler/bracket/header wrapped, main jet drilled out. All engines serial numbers and the seal numbers and locations
are recorded prior to sale. The engines MUST be run as purchased unless otherwise stated in this section.
10.3.C.3 Exhaust System: Any single stage, one piece header made from .750” O.D. Steel tubing with a maximum I.D. Dimension of .635”
allowed. Must have a Briggs #89966 tube type muffer, it's aftermarket equivalent, an RLV #4117 muffler installed at the end of the header. Muffler
may be welded to header or threaded into a welded on coupler. If threaded, it may have a spot weld to keep it from vibrating loose. Header must
have a minimum length of 10”, maximum length of 14”, INLUDING MUFFLER! To be measured from engine mounting flange to tip of muffler, following
along the outside radius of the longest bend. Muffler must remain stock as produced. Tack welds to prevent “shell” from blowing apart are
permitted. Header MUST be heat wrapped from flange to start of muffler. Muffler MAY NOT be wrapped. Brackets to reduce vibration/breakage
HIGHLY RECOMMENDED. Any aspect of the exhaust not compliant will result in disqualification with the following exception: If a tube type muffler is
found with the internal baffle plug missing post-race, that car will be penalized to last place in that event. The same will apply for the RLV muffler if
the “screen” in the end of the muffler has blown out. Mufflers found to have been tampered with will be grounds for DQ.
10.3.C.4 Carburetor: Huayi type carb only. Choke assembly must be in place and functional, but may be fastened in the open position. Choke
bore .810” dia max, venturi .615” max and throttle bore .751” max. NO MACHINING OF CARB BORE. Stock butterfly and screws must be used and
unaltered. Plastic spacer behind carb must be used and unaltered. Main metering jet, idle jet, and emulsion tube are non-tech. Throttle linkage non
tech. 1 stock type gasket allowed for all mating surfaced. NO spacers allowed other than stock parts.
10.3.C.5 Aftermarket air filter adapter allowed. Maximum length 1.375”. Air filter non tech.
10.3.C.6 Fuel Tank: Remote/floor mounted tank MUST be used. Any pulse type fuel pump permitted. MUST be pulsed from the valve cover.
10.3.C.7 Fuel: Gasoline only. No exotic fuels or additives. Pump around system may be used at track's discretion.
10.3.C.8 Valve Train: OEM push rods, push rod guide plates, retainers, keepers, adjusters, and stock 1:1 ratio OEM rocker arms only. OEM
valves with 45 degree seat angle only and no lightening or polishing. Valve springs may be changed, but must meet the following specs:
Maximum spring diameter - .798”
Maximum wire diameter - .073”
Maximum tension - 10.8 lbs at installed height of .850”, to be tested with AKRA certified tester.
10.3.C.9 Fasteners: Non-tech, but must retain their original factory size. Heli-coils, studs, etc allowed for repair purposes.
10.3.C.10 Gaskets & Sealer: Gaskets are non-tech and sealer may be applied unless otherwise specified.
10.3.C.11 Crankcase breathers are to be routed internally through the valve cover as originally intended in OEM configuration. No additional
breathers allowed.
10.3.C.12 Pull Starter: The pull starter mandatory and must be in place anytime the kart is on the track. Starter may be removed for cleaning,
“clocking”, or rope replacement.
10.3.C.13 Sealed Clone “Swap” Rule: No teams may claim engines. The track may confiscate any driver's engine following the feature on any
given night. That racer must go directly to the tech area and remove the engine. The engine must be given to the track officials as it is purchased
from MEI Smallcar/DH2 (complete long block – racer keeps throttle linkage, air filter and adapter, header, muffler, bracket, chain guard, clutch and
key, top plate, fuel pump and hoses, breather hose, motor plate). The racer will be given a “loaner” engine to use for 1 race (this engine may be a
used track rental engine or a brand new sealed engine at the tracks discretion). During this time, their engine will be checked for tampering and
legality. Following the 1 race with the loaner motor, the track will make a decision whether to return the engine, or replace it with a new one. In
other words, you are racing for your engine back... if you run at a level of competitiveness that you had been with your motor with the track engine,
then it is most likely not the engine and you will probably get yours back. If not, then the engine may be “over competitive” and it may, at the track's
discretion, be removed from competition.
10.3.C.14 Anyone refusing to surrender their engine will be banned from the sealed engine divisions permanently. The engine in question will
also be deemed illegal and banned from competition in the sealed engine divisions.
10.3.C.15 Any engine “swapped out” by the track and found to have been tampered with, either the seals or any parts, will result in the racer
being fined all points earned in the division that season and banned from the sealed engine divisions permanently. In the event that two drivers
share a kart, BOTH drivers will be penalized.
10.3.C.16 Seals may not be removed or tampered with in any way. Any engine with seals in question will be immediately subject to the track
claim.
10.3.C.17 Parts inside the sealed components (flywheel cover, side cover, cylinder head) may not be removed, machined, changed, or
tampered with in any way. If any engine is in need of repairs in these areas, it must be returned to WVMP to be repaired and re-sealed. A list of
such repairs and the flat rate prices will be posted on the track website.
10.3.C.18 Stock kill switch must be functional and in stock location.
10.3.C.19 Clutch: Stamped steel drum type clutch only. Two shoes maximum. No machined drums. Parts must remain as produced, no
machining. Springs may be changed to adjust engagement. NO DISC CLUTCHES.
10.3.D DH2 STOCK APPEARING CLONE ENGINE SPECIFICATIONS
10.3.D.1 Any 6.5hp “Clone” engine may be used. Must begin with stock block/side cover. All internaL modifications allowed. “Patch” may be
welded onto block for hole repair from rod damage. NO external modifications with the following exceptions:
1) Hole for governor rod may be tapped and plugged.
2) Low oil sensor hole may be plugged.
3) Hole may be drilled and tapped for pulsing of fuel pump.
10.3.D.2 Must begin with stock cylinder head casting. No visible external modifications. All internal machining, porting, polishing, and modifications
allowed.
10.3.D.3 Connecting rod: Billet rod mandatory. Any manufacturer. Must be used as manufactured, unaltered.
10.3.D.4 Piston & Rings: Non-tech.
10.3.D.5 Flywheel: Billet flywheel mandatory. Any manufacturer. Must be used as manufactured, unaltered.
10.3.D.6 Flywheel fan non-tech.
10.3.D.7 Stock type coil must be used. Timing non-tech.
10.3.D.8 Camshaft and Valve Train non-tech. Stock valve cover must be used unaltered with the exception of drilling and tapping to pulse fuel
pump. No spacers underneath. 1 gasket only.
10.3.D.9 Carb: Any 6.5 hp OEM Clone Carb Allowed. No external modifications allowed with the exception of throttle linkage modifications. All
internal modifications allowed. Emulsion tube, idle and main jets non-tech. Choke plate & shaft may be removed. Holes must be plugged.
Externally, casting must appear stock with no visible epoxy.
10.3.D.11 Air Filter & Adapter: Non-Tech
10.3.D.12 Starter recoil: Non-Tech
10.3.D.13 Header: Non-Tech. Must be wrapped.
10.3.D.14 Muffler: RLV Muffler used in the WKA stock raptor and animal classes mandatory, must be unaltered.
10.3.D.15 Fuel: MUST run methanol. No additives or exotic fuels. Pump around may be used at track's discretion.
10.3.D.16 Fuel Tank/Pump: Remote fuel tank mandatory. Fuel pump may be pulsed from valve cover, side cover, or crankcase.
10.3.D.17 Breather: Non-Tech
10.3.D.18 Clutch: Disc type clutch allowed. No wet clutches.
10.3.D.19 Fasteners: Non-Tech. Stud kits may be used where desired.
10.4 SLINGSHOTS All Speedway Entertainment Slingshot rules apply unless exception is listed.
10.4.A Older body styles may still be run provided it is a past SE body. NO CUSTOM OR HOME MADE BODIES!
10.4.B Body must be 2008 style or newer for all SE Tour Events.
10.5 270cc MICROSPRINTS (Regular)
10.5.1 All cars should be constructed to look like microsprints. All cars must be equipped with complete body panels (hood, tail, side panels,
belly pan, etc.)
10.5.2 Roll cages must be constructed of 4130 chrome moly tubing. Minimum diameter 1 ¼” OD, .065” wall thickness OR 1” OD .083” wall
thickness.
10.5.3 Belly pan must extend from the front of the seat to the nose of the car.
10.5.4 All steering and suspension parts that are bolted together must use locking nuts, safety wire, or cotter pins.
10.5.5 All cars must be equipped with nerf bars extending to at least the inside edge of the front tire and middle of the rear tire. May not
extend beyond the outside of the tread width of any tire.
10.5.6 No centrifugal clutches or belt drives.
10.5.7 4 point racing harness mandatory, minimum width of 2 ½”. May not be more than 5 years old as of first race of the season.
10.5.8 With driver seated in car, there must be a minimum of 3" of clearance between the driver's helmet and the top of the upper roll bar.
10.5.9 Brakes must be of sufficient strength as to stop the wheels in the pits or stop the car while in motion on the track.
10.5.10 Car must be equipped with a fuel shutoff valve and kill switch. Both must be functional, within reach of the driver, and clearly marked.
10.5.11 Sharp pointed objects will not be tolerated. Rear axles may not extend past the outer bead of the rear wheels when checked with a
straight edge.
10.5.12 Radiators should be mounted in a manner that makes it highly unlikely that it will be contacted by another car.
10.5.13 Steering mechanism must be constructed of a minimum of 5/8” rod and 3/8” heims.
10.5.14 Cars must have front and rear bumpers. Rear bumper must be suitable for push start. Track not responsible for car damage due to
push starting or pushing/removing from track.
10.5.15 Wheelbase - 56” minimum, 72” maximum.
10.5.16 Overall width - Shall not exceed 59” sidewall to sidewall.
10.5.17 All wheels must be race approved, 8" or 10" diameter only.
10.5.18 Engine Specs: Any single cylinder 250cc full production engine. Maximum of 271cc permitted. No forced air induction or fuel injection.
Any height compression head is legal. Gas or alcohol only! No additives other than top end lube.
10.5.19 Sprint car type window net RECOMMENDED on left side of the cage.
10.5.20 Welded Spindles must have skid plates
10.5.21 All cars must start the race with a top wing. Must be securely fastened. If damaged during race, car may continue provided it is still
reasonably secure. No car will race without top wing.
10.5.23 Top wing may not exceed 12 sq. ft. Side panels must not obstruct the view of the driver and cannot extend past the center section by
more than 10 inches, front or back. 24” x 54” side panel maximum.
10.5.24 Nose wings allowed. Maximum size 576 Sq. In. Must not mount forward of front bumper.
10.5.25 QUIET PIPES ARE REQUESTED IF YOU HAVE ONE! If noise
becomes an issue with the township, they will become MANDATORY!
10.5.26 All added weights must be painted white with car number clearly marked on it. Weights must be securely fastened with locknuts, double
nutted, or must be drilled and secured with a cotter key.
10.6 ROOKIE 270cc MICROSPRINTS
10.6.1 Car must meet all regular 270cc Microsprint rules.
10.6.2 Being DH2's first season with these cars, all drivers are technically rookies. We are unable to verify where or when any driver that
enters has raced. We DO discourage any driver with 3 or more years of microsprint racing experience from entering the Rookie 270 division. This
division is truly meant for rookies. It is not intended to be a career division. This is part of the reason the payout for the division is lower than the
regular 270 microsprints. Being able to race the same car for more money is part of the incentive for a driver to move up when they feel they are
ready. The purpose of the division is to allow drivers to gain experience with the cars and to help foster growth of the division at DH2.
10.6.3 Any driver winning 3 or more races during the season will not be eligible to run the rookie division once the current season ends.
10.6.4 The current season's division champion will not be eligible to run the rookie division once the current season ends.
10.6.5 DRIVERS may run in one 270 division per night ONLY. CARS may be used in both 270 divisions on the same night (in other words, an
experienced driver may compete in the regular 270's and an eligible rookie may use the same car on the same night in the rookie division.
10.6.6 If a driver feels they are ready, they may enter the regular 270 division at any time. A driver may run up to 2 regular 270 races in one
season (need not be run consecutively) and still return to the rookie division. Once a driver has run 3 regular 270 races in the same season, they
are no longer eligible to run in the rookie division.
10.7 600cc Microsprints
10.7.1 All cars should be constructed to look like microsprints. All cars must be
equipped with complete body panels (hood, tail, side panels, belly pan, etc.)
10.7.2 Roll cages must be of a 6 point design. Main cage must be 1.25” tubing (.065” wall if using chrome moly, .120” wall if using mild
steel). All bends must be made of a 3” minimum radius (no square or pointed corners allowed).
10.7.3 Kill Switch – MANDATORY, must be within reach of driver. Preferred location is on the right side of dash. Should be visible to safety
crews and clearly labeled.
10.7.4 Belly pan must extend from the front of the seat to the nose of the car.
10.7.5 Fuel bladder or sprint type fuel cell MANDATORY. Must be fully protected and securely mounted. Must be separate from the
drivers compartment. No pressurized fuel systems. A fuel tank with a bladder is further defined as a plastic outer shell with a rubber inner container.
10.7.6 All steering and suspension parts that are bolted together must use locking nuts, safety wire, or cotter pins.
10.7.7 All cars must be equipped with nerf bars extending to at least the inside edge of the front tire and middle of the rear tire. May not
extend beyond the outside of the tread width of any tire. Minimum diameter ¾” O.D., .065” wall mild steel. No sharp or pointed edges.
10.7.8 Bumpers – Must be present front and rear. Must be securely attached and suitable for towing. Width may not extend past outside
of main frame rail.
10.7.9 Must be chain drive. No centrifugal clutches or belt drives. No shaft drive.
10.7.10 5 point racing harness mandatory, minimum width of 2 ½”. May not be more than 5 years old as of first race of the season.
10.7.11 With driver seated in car, the driver's helmet may not be higher than 3" below the bottom of the upper roll bar.
10.7.12 Brakes must be of hydraulic type and sufficient strength as to stop the wheels in the pits or stop the car while in motion on the track.
Must have brakes on the rear axle. Front wheel brakes optional.
10.7.13 Car must be equipped with a fuel shutoff valve and kill switch. Both must be functional, within reach of the driver, and clearly
marked.
10.7.14 Throttle must be foot operated. Return strap highly recommended.
10.7.15 NO electronic traction control devices permitted.
10.7.16 Radiators/oil coolers should be mounted in a manner that makes it highly unlikely that it will be contacted by another car. May NOT be
mounted in drivers compartment.
10.7.17 No sail panels allowed on any part of car, including sidebars. Side panels may not protrude more than 2 inches behind rear down tubes.
10.7.18 Sides of chassis must have panels installed. Must have sprint type tail tank. Must run sprint or modified style hood.
10.7.19 Screen over windshield area highly recommended.
10.7.20 Suspension on all 4 wheels. May be of coil over, torsion bar, or leaf spring design.
10.7.21 Steering mechanism must be constructed of a minimum of 5/8” rod and 3/8” heims. Steering wheel hub must be of quick release or pin
style.
10.7.22 All radius tubes should be a minimum of 9/16” diameter with a wall thickness of .120”.
10.7.23 Wheelbase - 50” minimum, 72” maximum.
10.7.24 Overall width - Shall remain between 58"- 65" sidewall to sidewall.
10.7.25 All wheels must be race approved, 10" diameter only. Steel, aluminum, or carbon fiber wheels are acceptable. Beadlocks
recommended.
10.7.26 One piece live rear axle only. No quickchange or differential type rear ends. No accessories (hubs, sprocket, etc.) may be welded to
the axle. Nut or snap ring must be present at end of axle to prevent wheels from coming off. End of axle may not protrude beyond outer wheel bead
when checked with a straight edge.
10.7.27 A firewall must separate driver from engine compartment.
10.7.28 All bolts should be grade 5 minimum and should use locknuts, lock washers, or be safety wired or cotter keyed.
10.7.29 Sprint car type window net RECOMMENDED on left side of the cage.
10.7.30 All cars must have a top wing at all times. Must be securely fastened. If damaged during race, car may continue provided it is still
reasonably secure. NO CARS WILL RUN WITHOUT TOP WING! Top wing may not exceed 16 sq. ft., 48” long x 48” wide maximum. Side panels
must not obstruct the view of the driver. 22” tall, 56” long right side board maximum (may taper down at front). 28” tall x 56” long left side board
maximum. Wing sliders permitted.
10.7.31 Nose wings allowed. Maximum size 576 Sq. In. Must not mount forward of front bumper.
10.7.32 Wet cell battery mounted in the cockpit must be covered and vented.
10.7.33 All added weights must be painted white with car number clearly marked on it. Weights must be securely fastened with locknuts, or must
be drilled and secured with a cotter key.
10.7.34 Minimum weight at all times is 775 pounds.
10.7.35 ENGINE RULES: The word “Stock” means unmodified factory original parts or components.
10.7.35.A No limited production race motors allowed. Must be a production motorcycle engine, 4 cylinders, 4 stroke. No titanium anywhere in or
on the engine, unless it comes stock from engine manufacturer on the production bike. Must have engine, clutch, and transmission all in one unit.
Must be chain drive.
10.7.35.B Bore and stroke: 600cc Maximum displacement for an engine model that was new in 2006 or newer. Older engines maximum
displacement is 637cc. Engine model is defined as a manufacturer redesign of overall engine. See Specification list.
10.7.35.C No strokers or de-stroked engines
10.7.35.D Head and cams: NO PORTING or deporting of intake or exhaust runners. Valve jobs, valve grinding, valve seating, valve seal
modification and valve seat cutting are allowed. Valve seat inserts may be reworked or replaced with any seat of original dimensions. Any
dimensional thickness of the stock inserts may not be increased. Valve seats can be ground with multiple angles. Blending of the valve seat into the
head is permitted but cannot extend more than ¼” into the aluminum head measured from where the seat meets the head. OEM Head only. Cam
may not have a higher lift than the stock factory cam. (duration is open). Valves can not be larger in diameter than factory stock valves.
10.7.35.E Bottom End: No machining to remove weight from the crank. Balancing of crank is ok. No after-market cranks, no lightweight cranks.
No aluminum connecting rods. No dry sump systems are allowed unless it comes from the motorcycle manufacturer as original equipment.
10.7.35.F Clutch/Transmission: No removal of clutch. Clutch must remain operational. No modification to the stock transmission gears, no
close-ratio gears or nonstandard gear-ratios. All gears must remain in transmission, no removing any gears.
10.7.35.G Ignition: No aftermarket ECU’s, stock appearing ECU only. Reflashing of ECU and factory race ECU’s are allowed. May use different
year ignitions from same manufacturer. No aftermarket coils. No gear position sensor may be used. The sensor may be in place on the engine, but
can not have any wires connected to it. Gear position wire from ECU may not be switchable. No traction control device. No more than one ECU box
present in or on car.
10.7.35.H Air Induction System: No mechanically forced induction (turbo charging, supercharging). Any carburetors may be used on any
engine, regardless of year of engine. If the engine did not come from the factory with fuel injection, fuel injection may not be used. No after market
throttle bodies. Mechanical Fuel Injection (MFI) can be used.
10.7.35.I Exhaust: A muffler must be used with the exhaust system that will keep noise levels reasonable.
10.7.35.J Charging System: No removing the charging system, it must remain in complete working order, no factory racing charging systems.
10.7.35.K The engine must self-start at the beginning of the event. If it does not self-start, the car may be pushed off and must start at the rear
of the event as the penalty.
10.7.35.L Fuel: No fuels other than alcohol, gasoline, and/or top lube. Non flammable top lube only, no exotic fuel additives, no oxidizers, no fuel
enhancer top lube.
Engine Spec List
Engine / Disp. / Model Yr. Bore Stroke In Cam Ex Cam 1st 2nd 3rd 4th 5th
Kawasaki 636cc ZX-6R 03-04 68mm 43.8mm 7.9mm 7.1mm 5.910 4.155 3.482 2.932 2.572
Kawasaki 636cc ZX-6R 05-06 68mm 43.8mm 7.9mm 7.1mm 5.527 3.894 3.158 2.742 2.405
**Kawasaki 600cc ZX-6R 07-12 67mm 42.6mm 8.3mm 7.5mm 5.157 4.180 3.515 3.040 2.700
Yamaha 600cc R6 99-02 65.5mm 44.5mm 7.9mm 7.5mm 5.564 3.806 3.042 2.606 2.326
Yamaha 601-637cc R6 99-02
Yamaha 600cc R6 or (R6S) 03-05 (08) 65.5mm 44.5mm 8.5mm 7.6mm 5.564 3.806 3.042 2.606 2.326
Yamaha 601-637cc R6 or (R6S) 03-05 (08)
**Yamaha 600cc R6 06-12 67mm 42.5mm 8.5mm 7.7mm 5.355 4.146 3.456 2.993 2.666
Suzuki 600cc GSXR 01-03 5.364 3.952 3.238 2.793 2.511
Suzuki 601-637cc GSXR 01-03
Suzuki 600cc GSXR 04-05 67mm 42.5mm 8.6mm 7.3mm 5.364 3.952 3.238 2.793 2.511
Suzuki 601-637cc GSXR 04-05
**Suzuki 600cc GSXR 06-07 67mm 42.5mm 8.6mm 8.0mm 5.497 4.051 3.383 2.961 2.659
**Suzuki 600cc GSXR 08-12 67mm 42.5mm 8.2mm 8.0mm 5.497 4.051 3.383 2.961 2.659
Honda 600cc CBR F1-F3 90-98
Honda 601-637cc CBR F1-F3 90-98
Honda 600cc CBR F4 99-04 67mm 42.5mm 8.5mm 7.2mm 5.162 3.757 3.001 2.589 2.277
Honda 601-637cc CBR F4 99-04
Honda 600cc CBR RR 05-06 67mm 42.5mm 8.3mm 7.2mm 5.628 4.089 3.401 2.974 2.662
Honda 601-637cc CBR RR 05-06
**Honda 600cc CBR RR 07-12 67mm 42.5mm 8.3mm 7.2mm 5.805 4.222 3.517 3.048 2.753
** =Must remain 600cc
PPR =Pulses Per Revolution for tach setting
In Cam and Ex Cam = Maximum Cam Lift for intake and exhaust
1st, 2nd, 3rd, 4th, 5th , and 6th = Stock Primary x Secondary Transmission Ratios
This is the relationship between the crank and the output shaft in the respective gears.