liquidqwik
Justin Anderson
The Box Stock rules are as follows (using AKRA standards)
AKRA BOX STOCK/6.5 CLONE 2011 RULES ENGINE SPECIFIC TECH SHEET FOR: BOX STOCK 6.5 OHV
Description: Single cylinder, 2 valve, OHV 4 cycle
Combustion chamber volume: 26.5 cubic centimeter minimum, with piston at TDC, using prescribed procedure.
Cylinder Head Requirements: Must be OEM casting only. Porting and / or grinding are not permitted. Valve seats are two angles 45 degrees valve face and 30 degrees top relief. Intake seat maximum ID .897” , Exhaust seat maximum ID .862”. Stock head bolts only, must have four. Head gasket/s maybe after market, must be of stock configuration, 2 gaskets permitted with a total minimum thickness of .008” and maximum of .020”. No copper or aluminum gaskets allowed. Any stock configuration exhaust gasket allowed no other sealer.
Block Requirements: Stock cylinder bore is 2.685” max. Stroke is 2.123” + .010” or - .005”. No piston pop-out allowed. Matting surface finish of block and cylinder head is a non tech item, sufacing of both to correct gasket failure and meet cc check allowed. May use 2 side cover gaskets of stock configuration. Block must remain stock as produced. Stub for governor may be removed and hole plugged. No machining of block allowed. Welding to the block shall be for rod damage repair only and may not constitute a functional modification.
Carburetor requirements: Huayi OR RUI*ING model carb only. Carb to intake sealer is gasket only no other sealer allowed. Choke must be as supplied from factory, but may be fixed to stay in open position. Venturi .615” NO-GO. Rear carb bore .751” NO-GO. Main fuel jet .042” NO-GO. Low speed idle jet .019” NO-GO. Stock emulsion tube must be used and unaltered, .066’ max ID (no pass through). Throttle shaft - .115” minimum. Butterfly - .037” minimum. Aftermarket air filter adapter allowed (max length of 1.375).
Valve Train: Stock valve cover only with any stock configuration gasket, no sealer. Factory stock rocker arms 1:1 ratio and push rods only. Stock valves only 45 degree angle only both valves, Intake valve Max OD .985” +/- .005” and Exhaust valve Max OD .948” +/- .005”, no modifications allowed. Only Box Stock valve springs. Max wire diameter on spring wire is .071” with a maximum tension of 10.8 lbs. at a height of .850”. Lash cap on exhaust valve only. Valve stem seal allowed only on Intake valve, maximun lip tickness of .027”. Maximum thickness of Intake retainer .230” , Exhuast retainer .250” ( both +/- .005 tolerance). BS lifters only, no modifications allowed.
Ignition system: Stock Box Stock system only and must be unaltered. Kill switch and low oil sensor may be disabled and removed.
Flywheel: Box Stock flywheel (5lbs 4 oz minimum) including plastic fins. No alterations of any type allowed. Maximum ignition timing advance is 18° BTDC when a straight edge placed on the outside of the right-hand coil leg is just touching the right-hand edge of the metal magnet cover of the flywheel. Flywheel key is non-tech. Billet flywheel is optional but preferred for safety reasons.
Piston and Rings: Must be unaltered Box Stock only. No machining of piston and rings allowed.
Connecting Rod: Stock Box Stock rod only. No machining of any type allowed. Stock rod bolts only.
Crankshaft Requirements: Stock Box Stock crankshaft required. Machining, polishing, addition of material or other alteration 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.
Camshaft Requirements: Stock camshaft cores only, ez-spin assy must remain as stock. Cam lobe base circle diameter .865" -.005”/+.010” Duration check for Intake and Exhaust lobes (taken off pushrod). Intake duration of 219 degrees at .050 lift/86 degrees at .200 lift. Exhaust duration of 222 degrees at .050” lift/97 degrees at .200” lift(+/- 2 degrees for wear and gauge variances). Max Intake lift on cam .225” – Min .215”lift taken at the pushrod. Max Intake lift at the valve .238” Taken on valve spring retainer with zero lash. Max Exhaust lift on cam .232” – Min .222” lift taken at the pushrod. Max Exhaust Lift at the valve .242” Taken on valve spring retainer with zero lash.
Blower Housing Assembly: pull starter must be present and remain stock. Pull starter may be rotated for a better crank angle.
Header and Muffler Requirements: Open header rule
Fuel Tank Requirements: Floor Mounted fuel tank mandatory (stock tank must be removed). Pulse type fuel pump allowed.
Fuel Pump Requirements: Fuel pump must be pulsed from either the crank case or the valve cover. You may install a flat metal plate in the original tank location for the purpose of mounting the throttle linkage and fuel pump.
Clutches: Open clutch rule
RLV Mini 91 Silencer Requirements: Part # 4117 Overall Length 5.470” minimum +/- .005” – 5.600” maximum +/- .005” . Threaded Nipple .685” maximum ID (ID as Mfg. NO Grinding, Reaming, or Polishing Allowed) . Rear baffle holes .1285” maximum, inner baffle holes .0965” maximum. Silencer must be utilized as produced, with no modifications or alterations permitted. Strap or brace required to silencer for support, and to insure silencer does not turn and unscrew.
Claimer Rule: You must finish the race in the box stock class to purchase the winners engine for $200 (minus the clutch/chain guard/throttle kit, header pipe/muffler, air filter adaptor/air filter, top plate & fuel pump).
All racers still have the option to run the Builder Prepared Clone class as well with 3 or more karts. The builder prepared rules are already posted on the website.
www.bedrockraceway.com
AKRA BOX STOCK/6.5 CLONE 2011 RULES ENGINE SPECIFIC TECH SHEET FOR: BOX STOCK 6.5 OHV
Description: Single cylinder, 2 valve, OHV 4 cycle
Combustion chamber volume: 26.5 cubic centimeter minimum, with piston at TDC, using prescribed procedure.
Cylinder Head Requirements: Must be OEM casting only. Porting and / or grinding are not permitted. Valve seats are two angles 45 degrees valve face and 30 degrees top relief. Intake seat maximum ID .897” , Exhaust seat maximum ID .862”. Stock head bolts only, must have four. Head gasket/s maybe after market, must be of stock configuration, 2 gaskets permitted with a total minimum thickness of .008” and maximum of .020”. No copper or aluminum gaskets allowed. Any stock configuration exhaust gasket allowed no other sealer.
Block Requirements: Stock cylinder bore is 2.685” max. Stroke is 2.123” + .010” or - .005”. No piston pop-out allowed. Matting surface finish of block and cylinder head is a non tech item, sufacing of both to correct gasket failure and meet cc check allowed. May use 2 side cover gaskets of stock configuration. Block must remain stock as produced. Stub for governor may be removed and hole plugged. No machining of block allowed. Welding to the block shall be for rod damage repair only and may not constitute a functional modification.
Carburetor requirements: Huayi OR RUI*ING model carb only. Carb to intake sealer is gasket only no other sealer allowed. Choke must be as supplied from factory, but may be fixed to stay in open position. Venturi .615” NO-GO. Rear carb bore .751” NO-GO. Main fuel jet .042” NO-GO. Low speed idle jet .019” NO-GO. Stock emulsion tube must be used and unaltered, .066’ max ID (no pass through). Throttle shaft - .115” minimum. Butterfly - .037” minimum. Aftermarket air filter adapter allowed (max length of 1.375).
Valve Train: Stock valve cover only with any stock configuration gasket, no sealer. Factory stock rocker arms 1:1 ratio and push rods only. Stock valves only 45 degree angle only both valves, Intake valve Max OD .985” +/- .005” and Exhaust valve Max OD .948” +/- .005”, no modifications allowed. Only Box Stock valve springs. Max wire diameter on spring wire is .071” with a maximum tension of 10.8 lbs. at a height of .850”. Lash cap on exhaust valve only. Valve stem seal allowed only on Intake valve, maximun lip tickness of .027”. Maximum thickness of Intake retainer .230” , Exhuast retainer .250” ( both +/- .005 tolerance). BS lifters only, no modifications allowed.
Ignition system: Stock Box Stock system only and must be unaltered. Kill switch and low oil sensor may be disabled and removed.
Flywheel: Box Stock flywheel (5lbs 4 oz minimum) including plastic fins. No alterations of any type allowed. Maximum ignition timing advance is 18° BTDC when a straight edge placed on the outside of the right-hand coil leg is just touching the right-hand edge of the metal magnet cover of the flywheel. Flywheel key is non-tech. Billet flywheel is optional but preferred for safety reasons.
Piston and Rings: Must be unaltered Box Stock only. No machining of piston and rings allowed.
Connecting Rod: Stock Box Stock rod only. No machining of any type allowed. Stock rod bolts only.
Crankshaft Requirements: Stock Box Stock crankshaft required. Machining, polishing, addition of material or other alteration 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.
Camshaft Requirements: Stock camshaft cores only, ez-spin assy must remain as stock. Cam lobe base circle diameter .865" -.005”/+.010” Duration check for Intake and Exhaust lobes (taken off pushrod). Intake duration of 219 degrees at .050 lift/86 degrees at .200 lift. Exhaust duration of 222 degrees at .050” lift/97 degrees at .200” lift(+/- 2 degrees for wear and gauge variances). Max Intake lift on cam .225” – Min .215”lift taken at the pushrod. Max Intake lift at the valve .238” Taken on valve spring retainer with zero lash. Max Exhaust lift on cam .232” – Min .222” lift taken at the pushrod. Max Exhaust Lift at the valve .242” Taken on valve spring retainer with zero lash.
Blower Housing Assembly: pull starter must be present and remain stock. Pull starter may be rotated for a better crank angle.
Header and Muffler Requirements: Open header rule
Fuel Tank Requirements: Floor Mounted fuel tank mandatory (stock tank must be removed). Pulse type fuel pump allowed.
Fuel Pump Requirements: Fuel pump must be pulsed from either the crank case or the valve cover. You may install a flat metal plate in the original tank location for the purpose of mounting the throttle linkage and fuel pump.
Clutches: Open clutch rule
RLV Mini 91 Silencer Requirements: Part # 4117 Overall Length 5.470” minimum +/- .005” – 5.600” maximum +/- .005” . Threaded Nipple .685” maximum ID (ID as Mfg. NO Grinding, Reaming, or Polishing Allowed) . Rear baffle holes .1285” maximum, inner baffle holes .0965” maximum. Silencer must be utilized as produced, with no modifications or alterations permitted. Strap or brace required to silencer for support, and to insure silencer does not turn and unscrew.
Claimer Rule: You must finish the race in the box stock class to purchase the winners engine for $200 (minus the clutch/chain guard/throttle kit, header pipe/muffler, air filter adaptor/air filter, top plate & fuel pump).
All racers still have the option to run the Builder Prepared Clone class as well with 3 or more karts. The builder prepared rules are already posted on the website.
www.bedrockraceway.com
