Post by Announcer Dude on Dec 8, 2008 15:10:24 GMT -5
Clone Motor Rules
If the rules do not cover a specific rule, you should not make the modification to the engine. This class is intended to be a low cost alternative so please do not attempt to ‘read between the lines or create gray areas’. If the below listed rules do not cover it, you should not attempt to make the modification.
All parts can and will be checked against known stock parts unless a specific modification is specified in the below listed rules. No part can be cut, polished, ground, machined or altered in any way unless specifically covered in these rules. Due to manufacturing variables, when comparing stock parts, a small tolerance may be acceptable on certain parts of .002 to.005 but not in all circumstances where specific measurements have been put in place.
Stock Class – Blue or Yellow motor
BORE and STROKE
Standard bore is approximately 2.685 and standard stroke is 2.123. Unless otherwise stated, the maximum bore size will be 2.693 or .008 over. When factory replacement (oversized) pistons become readily available, this rule may be revised. Only stock, dish-top pistons may be used. All 3 rings must be used and remain unaltered in any way. Machining or altering the piston or rings in any way is not allowed.
STROKE
Stroke will be checked at 2.123, +/- .010 for wear. Piston pop-up must not be higher than .000 to the deck of the block. No pop-up above the deck.
CONNECTING ROD
Box stock rod only. No modifying or machining of any kind is allowed. The stock rod must also have the stock rod bolts. Factory stock rods only.
CYLINDER HEAD
Only the stock, factory installed head, 6.5hp head may be used. Cutting, porting or grinding is not allowed. Valve seats must be stock in size and location. Only 2 angles are allowed. 45 degree on face of seat where it mates with the face of valve and 30 degrees at top relief. All four head bolts must be used and these must be stock head bolts. Aftermarket gaskets are allowed but must remain in the stock configuration. Aluminum or copper gaskets are not allowed. The minimum combustion chamber depth is .270 to be measured in 3 places on the head. Heads cannot be machined except for sealing surfaces only. No welding, grinding or polishing in combustion chamber of head is allowed.
HEADER
Any brand of muffled header is allowed as long as it does not extend into the exhaust port. All headers must use a RLV, stock class muffler. Silicone may be used in place of a gasket only on the exhaust. Sealers of any type may not be used any where else on the motor.
VALVE TRAIN
The stock valve cover must be used and remain unaltered. Stock rocker arms, stud locks and adjusters must be used and remain unaltered. Stock push rods must be used with a diameter of .197 +/- of .003. Push rod length is 5.255 +/- .010. Stock, unaltered valves must be used with only one angle, 45 degrees on the face. Intake valve diameter is .982 +/- .005. Exhaust valve diameter is .944 +/- .005. Stock retainers and lash caps must be used. Any single valve spring can be used on the intake or exhaust valve.
COIL
Ignition timing can be changed with or without a key. Only the stock coil may be used and it must remain unaltered and mounted in the stock position. The kill switch and/or low oil sensor may be removed or disabled.
FLYWHEEL
The flywheel must remain stock and unaltered, as from the factory. The plastic cooling fins must be unaltered and complete. As an alternative, you may run an A.R.C. billet flywheel with or without the steel center hub but this flywheel must also remain unaltered, as from the factory.
BLOCK
The block must remain as from the factory with no modifications. Where the governor shaft goes through the block can be plugged. A single hole can be drilled/tapped for 1/8th pipe fitting in the block or top of the side cover for a pulse fitting for pump. In case of a broken rod, all welding repairs must be done below the cooling fins only.
CRANK SHAFT
Only the factory crank may be used and it cannot be polished, ground, machined or altered in any way, including adding metal. The factory timing gear must be used in the stock location. The crank journal diameter is 1.180 maximum and 1.175 minimum.
CAM SHAFT
Stock, cast cam shaft must be used with compression relief in place. Lift will be checked at valve spring retainer with .0 lash. The maximum valve lift will be .250.
CARBURATOR
Huayi or Ruiing model carbs are o.k. for the 6.5hp. The choke must be as from the factory and remain unaltered except to be tied or strapped in the ‘open’ position. Choke bore is to be check with a .810 no-go. Venturi will be checked with a .625 no-go. Rear bore of the carb will be checked with a .751 no-go. There will be no tech on the high side fuel jet or nozzle. There will be no tech on the throttle shaft or screw. An after market filter adapter and filter are acceptable. If using an after market filter and adapter, you must use a fabric, oilable filter with no open areas on it.
FUEL PUMP
An auxiliary fuel pump may be used but it must be a pulse type fuel pump. The fuel pump must also be a single line pump and must be pulsed from the block or side cover. The pulse line and fuel line maximum size is ¼ inch only. The maximum length of the pulse line will be 14 inches long.
If the rules do not cover a specific rule, you should not make the modification to the engine. This class is intended to be a low cost alternative so please do not attempt to ‘read between the lines or create gray areas’. If the below listed rules do not cover it, you should not attempt to make the modification.
All parts can and will be checked against known stock parts unless a specific modification is specified in the below listed rules. No part can be cut, polished, ground, machined or altered in any way unless specifically covered in these rules. Due to manufacturing variables, when comparing stock parts, a small tolerance may be acceptable on certain parts of .002 to.005 but not in all circumstances where specific measurements have been put in place.
Stock Class – Blue or Yellow motor
BORE and STROKE
Standard bore is approximately 2.685 and standard stroke is 2.123. Unless otherwise stated, the maximum bore size will be 2.693 or .008 over. When factory replacement (oversized) pistons become readily available, this rule may be revised. Only stock, dish-top pistons may be used. All 3 rings must be used and remain unaltered in any way. Machining or altering the piston or rings in any way is not allowed.
STROKE
Stroke will be checked at 2.123, +/- .010 for wear. Piston pop-up must not be higher than .000 to the deck of the block. No pop-up above the deck.
CONNECTING ROD
Box stock rod only. No modifying or machining of any kind is allowed. The stock rod must also have the stock rod bolts. Factory stock rods only.
CYLINDER HEAD
Only the stock, factory installed head, 6.5hp head may be used. Cutting, porting or grinding is not allowed. Valve seats must be stock in size and location. Only 2 angles are allowed. 45 degree on face of seat where it mates with the face of valve and 30 degrees at top relief. All four head bolts must be used and these must be stock head bolts. Aftermarket gaskets are allowed but must remain in the stock configuration. Aluminum or copper gaskets are not allowed. The minimum combustion chamber depth is .270 to be measured in 3 places on the head. Heads cannot be machined except for sealing surfaces only. No welding, grinding or polishing in combustion chamber of head is allowed.
HEADER
Any brand of muffled header is allowed as long as it does not extend into the exhaust port. All headers must use a RLV, stock class muffler. Silicone may be used in place of a gasket only on the exhaust. Sealers of any type may not be used any where else on the motor.
VALVE TRAIN
The stock valve cover must be used and remain unaltered. Stock rocker arms, stud locks and adjusters must be used and remain unaltered. Stock push rods must be used with a diameter of .197 +/- of .003. Push rod length is 5.255 +/- .010. Stock, unaltered valves must be used with only one angle, 45 degrees on the face. Intake valve diameter is .982 +/- .005. Exhaust valve diameter is .944 +/- .005. Stock retainers and lash caps must be used. Any single valve spring can be used on the intake or exhaust valve.
COIL
Ignition timing can be changed with or without a key. Only the stock coil may be used and it must remain unaltered and mounted in the stock position. The kill switch and/or low oil sensor may be removed or disabled.
FLYWHEEL
The flywheel must remain stock and unaltered, as from the factory. The plastic cooling fins must be unaltered and complete. As an alternative, you may run an A.R.C. billet flywheel with or without the steel center hub but this flywheel must also remain unaltered, as from the factory.
BLOCK
The block must remain as from the factory with no modifications. Where the governor shaft goes through the block can be plugged. A single hole can be drilled/tapped for 1/8th pipe fitting in the block or top of the side cover for a pulse fitting for pump. In case of a broken rod, all welding repairs must be done below the cooling fins only.
CRANK SHAFT
Only the factory crank may be used and it cannot be polished, ground, machined or altered in any way, including adding metal. The factory timing gear must be used in the stock location. The crank journal diameter is 1.180 maximum and 1.175 minimum.
CAM SHAFT
Stock, cast cam shaft must be used with compression relief in place. Lift will be checked at valve spring retainer with .0 lash. The maximum valve lift will be .250.
CARBURATOR
Huayi or Ruiing model carbs are o.k. for the 6.5hp. The choke must be as from the factory and remain unaltered except to be tied or strapped in the ‘open’ position. Choke bore is to be check with a .810 no-go. Venturi will be checked with a .625 no-go. Rear bore of the carb will be checked with a .751 no-go. There will be no tech on the high side fuel jet or nozzle. There will be no tech on the throttle shaft or screw. An after market filter adapter and filter are acceptable. If using an after market filter and adapter, you must use a fabric, oilable filter with no open areas on it.
FUEL PUMP
An auxiliary fuel pump may be used but it must be a pulse type fuel pump. The fuel pump must also be a single line pump and must be pulsed from the block or side cover. The pulse line and fuel line maximum size is ¼ inch only. The maximum length of the pulse line will be 14 inches long.
