dodgeram11
Member
Our track is starting to run the lo206. Everybody just buying the standard like 500 to 550 one. My question is for those of u who know more about these. How close out of the box are they o the rules. Is it worth it to buy a race ready one from a shop? My thoughts are they are sealed. O u can't change much. But maybe I don't understand. Here are our rules.
Briggs Local Option 206 Crate Engine Rules:
The intent of this class is to provide a sealed, simple to operate; ultra-dependable and ultra-reliable, engine using only factory parts.
The crankcase is sealed at the factory to help control costs and maintain equality while simplifying tech. Only the top end must be inspected. No engine may enter this class without a crankcase seal or with a seal that shows evidence of tampering.
This engine must be raced exactly as it comes from the factory. All parts must be B&S factory production parts unless otherwise noted in these rules. No machining or alteration of parts is permitted unless specifically noted in these rules. All parts are subject to comparison to a known stock B&S part.
Shrouds & Covers: Engine shroud may be painted any color. Engine shroud, covers, and control panel must be intact and not modified, Any bolt, except head bolts, used to secure sheet metal shrouds and covers may be replaced with a larger diameter bolt. Stock kill switch must remain in stock location and wires must remain in place. No taping or covering of the rewind shroud allowed.
Header and Silencer:
Header must be either RLV 5506 or RLV 5507.
Silencer must be RLV B91 with round baffle holes only. Holes are .128” NO-GO.
Gaskets and / or silicone allowed to seal header to head.
Studs or bolts allowed to fasten header to head. Bolts or nuts must be safety wired. Header support brace is mandatory.
Wrapping the header with material to protect participants from heat is encouraged. Wrapping of header from just above flange to the point where header falls below top of rocker cover is mandatory. Muffler may not be wrapped or welded to the pipe.
Air Filter: Air Filter. Air Filter not required. If Air Filter is used, must be B&S #555729. No filter adapters allowed.
Fuel and Fuel Pump: The fuel is gasoline. Unleaded 89 to 92 Octane only.
Fuel Pump Briggs and Stratton #557033 recommended. Fuel Pump must be pulsed from the top of the side cover only. Fuel Line and pulse line must be ¼” I.D. No extra fuel line anywhere in the system. Return fuel line from the pressure side of the pump is not allowed.
Carburetor: PZ Model 22 Carburetor only. Any 6mm bolts may be used to attach carb to manifold. Studs are not allowed. Carb to manifold seal is by O ring only. No sealer allowed. Air must enter carb at air horn only. Choke must be stock as from factory and must operate. Spring or rubber band may be used to hold choke lever in position.
Throttle Bore: I.D. is .874” NO-GO. Must be cast.
Choke Bore: I.D. is 1.149” NO-GO. Must be cast.
Venturi: Vertical Dimension is .792” NO-GO. Horizontal dimension is .615” NO-GO when .615” NO-GO is inserted horizontally into the air filter side of the venture; it may not pass into the slide area. When the .615” NO-GO is inserted horizontally into the manifold side of the venture, it may not enter the venture section at all. Must be as manufactured.
Air pick off hole: .061” NO-GO.
Venturi Idle Fuel Hole: 0.036” Max
Throttle Slide: Throttle slide must be B&S stock Unaltered. Slide cutaway to be measured on flat surface. 0.075” NO-GO.
Jets: must be stock gasoline jets only. Factory marking is required.
Needle Jet: BGB set at any notch.
Pilot Jet: #32, hole size is 0.0130” NO-GO
Main Jet: #95, hole size is 0.0380” NO-GO
Main Nozzle: OEM stock unaltered. Hole size .101” Min- .103” Max
Emulsion Tube: OEM stock unaltered 4 small holes .018” Min-.020” Max. 4 big holes .026” Min- .029” Max.
Overflow: from float bowl must be vented to each can.
Intake Manifold: Length of manifold must be from 1.740” minimum to 1.765” maximum.
Inside Diameter must be .885” must go minimum, .905” NO-GO maximum.
Stock Manifold: stock manifold to block gasket required.
Rocker Cover: Stock rocker cover from factory is required.
Rocker cover gasket must be stock. No sealer allowed.
Filter or tubing to a catch can may be fitted to outlet. No welding or tapping of rocker cover allowed.
An oil overflow catch system is mandatory. Overflow catch tube must be run from the crankcase breather to a catch container. The catch container must be vented to the atmosphere.
Camshaft and Ignition Timing: First Camshaft check will be taken at the valve spring retainers. With lash set at zero, the movement of the valve spring retainer may not exceed 0.255 Intake and Exhaust Maximum.
Install degree wheel, using positive stop method.
Check ignition time for PVL coil and flywheel: with the left edge of the right coil leg aligned with the right edge of the right magnet, the motor must be from 23 degrees BTDC to 27 degrees BTDC.
Coil: Unaltered / Coil unit is “green” B&S #555718 Mandatory. Maximum RPM limit 6150.
Attachment bolts must not be altered.
Spark Plug Connector must be B&S #555714
Coil Air Gap is not tech. recommended .014”
Spark Plug: Only unaltered, B&S #555737, Champion RC12YC, spark plug with B&S logo allowed. Sealing washer must be in place as from the factory.
Valve Operating Mechanism:
Rocker Arm: Must be unaltered from stock. Overall length 2.850” minimum.
Ball Rocker: must be stock. Diameter .600” +/- .010”
Push Rods: must be stock. Diameter .185” - .190”
Length is 5.638” – 5.658”.
Head Bolts: Four stock head bolts are mandatory.
Head Gaskets: Unaltered B&S #555723 is the only head gasket allowed.
Cylinder Head Plate: Must be stock.
Cylinder Head plate gasket must be stock with maximum thickness of .055”.
Rocker arm studs: Must be stock.
Valves: Stock Valves Only. One angle only. Valve may not be polished or lightened. If working area (that portion of the valve stem translating with the valve guides) of valve stem is cleaned, no material may be removed. No grooves, cross hatching etc.
Intake Valve: 45 degree face. Head diameter is 1.055” – 1.065”. Intake valve minimum weight 29.26 grams.
Exhaust Valve: 45 degree face. Head diameter is .935” - .945” exhaust valve minimum weight 28.62 grams.
Length of Valves must be 3.355” to 3.390”.
Valve Springs: Stock B&S valve springs and keepers are mandatory. Springs must remain unaltered as supplied from the factory. WARNING: Aftermarket springs with higher spring rate will result in damage to the camshaft.
Maximum valve spring length is .930” Wire diameter is .103” to .107”, measured in three places on the spring. Inside diameter of spring is .615” minimum to .635” maximum.
Valve Spring Retainers: Thickness is .055” - .070”
Cylinder Head: Stock B&S RT1 casting as shipped from the factory is the only configuration approved. No machining of head allowed. Machining marks left on head gasket surface area tech item. Bosses on back of head, just below valve cover gasket surface may be tapped for attachment of header supports.
Combustion Chamber: Hard carbon may be scraped from head before measuring.
From head gasket surface the depth of the head at shallow part is .030” minimum. Depth at floor of head is .340” minimum.
Depth to the top of valve seats is .340” minimum .360” Maximum.
Shoulders of Sox tool # AT 341 may not touch head gasket surface when tool is placed into combustion chamber.
Minimum thickness of cylinder head is 2.430”.
Valve Seats: Most have only 45 degree angle on valve seats. Stock B & S seats are mandatory.
Intake seat diameter is .966” - .972”.
Exhaust seat diameter is .841” - .850”.
Ports: Must be stock, no machining, polishing, and easing.
Intake inlet port: .918” No-Go. When checking 90 degrees to line between center of studs, no-go will be straight. When checking online with center of studs, No-Go will set on floor of port at bottom and stop at upper edge of port on top.
Exhaust outlet: .980” No-Go
Valve guides must be stock as supplied from factory. Maximum depth from the head gasket surface to the intake valve guide is 1.255”.
Deck/Piston: No machining of the dock surface is permitted. Factory machining marks on deck are a tech item. Arrow on piston must point to the flywheel side of motor. Maximum pop out allowed is 0.005” measured with flat bar set on top of piston parallel and 90 degrees to wrist pin.
Cylinder Bore: Stock bore is 2.690”. Allowance for wear is permitted, up to 2.697”.
Stroke: Maximum stroke is 2.204”. Push piston down to take up rod play. Check stroke from BDC to TDC.
Flywheel: B &S PVL flywheel with plastic fins is the only flywheel permitted. No machining, glass beading, sandblasting, painting or coating of flywheel is allowed. Minimum factory overspray is allowed.
Plastic fins are required. All fins must be in place.
Stock flywheel key with B&S logo is required. Width of key allowed is .1825” - .1875”.
Minimum weight of flywheel, fins and fin attachment bolts is 4 pounds, 1 ounce.
Cylinder and side cover: Unaltered seal must be in place. No alterations or welding are allowed to any component.
Clutch: Novice class must run Max Torque Clutch only; B&S #555727, no alterations to clutch other than springs. No exceptions. Jr1, Jr2, Senior, and Masters classes may run any rim centrifugal clutch with a maximum of 9 springs and 6 shoes. No alterations to clutch allowed other than springs. No clutch coolers allowed.
Starter: Recoil starter must be retained, as produced and intact. Starter may be rotated.
Briggs Local Option 206 Crate Engine Rules:
The intent of this class is to provide a sealed, simple to operate; ultra-dependable and ultra-reliable, engine using only factory parts.
The crankcase is sealed at the factory to help control costs and maintain equality while simplifying tech. Only the top end must be inspected. No engine may enter this class without a crankcase seal or with a seal that shows evidence of tampering.
This engine must be raced exactly as it comes from the factory. All parts must be B&S factory production parts unless otherwise noted in these rules. No machining or alteration of parts is permitted unless specifically noted in these rules. All parts are subject to comparison to a known stock B&S part.
Shrouds & Covers: Engine shroud may be painted any color. Engine shroud, covers, and control panel must be intact and not modified, Any bolt, except head bolts, used to secure sheet metal shrouds and covers may be replaced with a larger diameter bolt. Stock kill switch must remain in stock location and wires must remain in place. No taping or covering of the rewind shroud allowed.
Header and Silencer:
Header must be either RLV 5506 or RLV 5507.
Silencer must be RLV B91 with round baffle holes only. Holes are .128” NO-GO.
Gaskets and / or silicone allowed to seal header to head.
Studs or bolts allowed to fasten header to head. Bolts or nuts must be safety wired. Header support brace is mandatory.
Wrapping the header with material to protect participants from heat is encouraged. Wrapping of header from just above flange to the point where header falls below top of rocker cover is mandatory. Muffler may not be wrapped or welded to the pipe.
Air Filter: Air Filter. Air Filter not required. If Air Filter is used, must be B&S #555729. No filter adapters allowed.
Fuel and Fuel Pump: The fuel is gasoline. Unleaded 89 to 92 Octane only.
Fuel Pump Briggs and Stratton #557033 recommended. Fuel Pump must be pulsed from the top of the side cover only. Fuel Line and pulse line must be ¼” I.D. No extra fuel line anywhere in the system. Return fuel line from the pressure side of the pump is not allowed.
Carburetor: PZ Model 22 Carburetor only. Any 6mm bolts may be used to attach carb to manifold. Studs are not allowed. Carb to manifold seal is by O ring only. No sealer allowed. Air must enter carb at air horn only. Choke must be stock as from factory and must operate. Spring or rubber band may be used to hold choke lever in position.
Throttle Bore: I.D. is .874” NO-GO. Must be cast.
Choke Bore: I.D. is 1.149” NO-GO. Must be cast.
Venturi: Vertical Dimension is .792” NO-GO. Horizontal dimension is .615” NO-GO when .615” NO-GO is inserted horizontally into the air filter side of the venture; it may not pass into the slide area. When the .615” NO-GO is inserted horizontally into the manifold side of the venture, it may not enter the venture section at all. Must be as manufactured.
Air pick off hole: .061” NO-GO.
Venturi Idle Fuel Hole: 0.036” Max
Throttle Slide: Throttle slide must be B&S stock Unaltered. Slide cutaway to be measured on flat surface. 0.075” NO-GO.
Jets: must be stock gasoline jets only. Factory marking is required.
Needle Jet: BGB set at any notch.
Pilot Jet: #32, hole size is 0.0130” NO-GO
Main Jet: #95, hole size is 0.0380” NO-GO
Main Nozzle: OEM stock unaltered. Hole size .101” Min- .103” Max
Emulsion Tube: OEM stock unaltered 4 small holes .018” Min-.020” Max. 4 big holes .026” Min- .029” Max.
Overflow: from float bowl must be vented to each can.
Intake Manifold: Length of manifold must be from 1.740” minimum to 1.765” maximum.
Inside Diameter must be .885” must go minimum, .905” NO-GO maximum.
Stock Manifold: stock manifold to block gasket required.
Rocker Cover: Stock rocker cover from factory is required.
Rocker cover gasket must be stock. No sealer allowed.
Filter or tubing to a catch can may be fitted to outlet. No welding or tapping of rocker cover allowed.
An oil overflow catch system is mandatory. Overflow catch tube must be run from the crankcase breather to a catch container. The catch container must be vented to the atmosphere.
Camshaft and Ignition Timing: First Camshaft check will be taken at the valve spring retainers. With lash set at zero, the movement of the valve spring retainer may not exceed 0.255 Intake and Exhaust Maximum.
Install degree wheel, using positive stop method.
Check ignition time for PVL coil and flywheel: with the left edge of the right coil leg aligned with the right edge of the right magnet, the motor must be from 23 degrees BTDC to 27 degrees BTDC.
Coil: Unaltered / Coil unit is “green” B&S #555718 Mandatory. Maximum RPM limit 6150.
Attachment bolts must not be altered.
Spark Plug Connector must be B&S #555714
Coil Air Gap is not tech. recommended .014”
Spark Plug: Only unaltered, B&S #555737, Champion RC12YC, spark plug with B&S logo allowed. Sealing washer must be in place as from the factory.
Valve Operating Mechanism:
Rocker Arm: Must be unaltered from stock. Overall length 2.850” minimum.
Ball Rocker: must be stock. Diameter .600” +/- .010”
Push Rods: must be stock. Diameter .185” - .190”
Length is 5.638” – 5.658”.
Head Bolts: Four stock head bolts are mandatory.
Head Gaskets: Unaltered B&S #555723 is the only head gasket allowed.
Cylinder Head Plate: Must be stock.
Cylinder Head plate gasket must be stock with maximum thickness of .055”.
Rocker arm studs: Must be stock.
Valves: Stock Valves Only. One angle only. Valve may not be polished or lightened. If working area (that portion of the valve stem translating with the valve guides) of valve stem is cleaned, no material may be removed. No grooves, cross hatching etc.
Intake Valve: 45 degree face. Head diameter is 1.055” – 1.065”. Intake valve minimum weight 29.26 grams.
Exhaust Valve: 45 degree face. Head diameter is .935” - .945” exhaust valve minimum weight 28.62 grams.
Length of Valves must be 3.355” to 3.390”.
Valve Springs: Stock B&S valve springs and keepers are mandatory. Springs must remain unaltered as supplied from the factory. WARNING: Aftermarket springs with higher spring rate will result in damage to the camshaft.
Maximum valve spring length is .930” Wire diameter is .103” to .107”, measured in three places on the spring. Inside diameter of spring is .615” minimum to .635” maximum.
Valve Spring Retainers: Thickness is .055” - .070”
Cylinder Head: Stock B&S RT1 casting as shipped from the factory is the only configuration approved. No machining of head allowed. Machining marks left on head gasket surface area tech item. Bosses on back of head, just below valve cover gasket surface may be tapped for attachment of header supports.
Combustion Chamber: Hard carbon may be scraped from head before measuring.
From head gasket surface the depth of the head at shallow part is .030” minimum. Depth at floor of head is .340” minimum.
Depth to the top of valve seats is .340” minimum .360” Maximum.
Shoulders of Sox tool # AT 341 may not touch head gasket surface when tool is placed into combustion chamber.
Minimum thickness of cylinder head is 2.430”.
Valve Seats: Most have only 45 degree angle on valve seats. Stock B & S seats are mandatory.
Intake seat diameter is .966” - .972”.
Exhaust seat diameter is .841” - .850”.
Ports: Must be stock, no machining, polishing, and easing.
Intake inlet port: .918” No-Go. When checking 90 degrees to line between center of studs, no-go will be straight. When checking online with center of studs, No-Go will set on floor of port at bottom and stop at upper edge of port on top.
Exhaust outlet: .980” No-Go
Valve guides must be stock as supplied from factory. Maximum depth from the head gasket surface to the intake valve guide is 1.255”.
Deck/Piston: No machining of the dock surface is permitted. Factory machining marks on deck are a tech item. Arrow on piston must point to the flywheel side of motor. Maximum pop out allowed is 0.005” measured with flat bar set on top of piston parallel and 90 degrees to wrist pin.
Cylinder Bore: Stock bore is 2.690”. Allowance for wear is permitted, up to 2.697”.
Stroke: Maximum stroke is 2.204”. Push piston down to take up rod play. Check stroke from BDC to TDC.
Flywheel: B &S PVL flywheel with plastic fins is the only flywheel permitted. No machining, glass beading, sandblasting, painting or coating of flywheel is allowed. Minimum factory overspray is allowed.
Plastic fins are required. All fins must be in place.
Stock flywheel key with B&S logo is required. Width of key allowed is .1825” - .1875”.
Minimum weight of flywheel, fins and fin attachment bolts is 4 pounds, 1 ounce.
Cylinder and side cover: Unaltered seal must be in place. No alterations or welding are allowed to any component.
Clutch: Novice class must run Max Torque Clutch only; B&S #555727, no alterations to clutch other than springs. No exceptions. Jr1, Jr2, Senior, and Masters classes may run any rim centrifugal clutch with a maximum of 9 springs and 6 shoes. No alterations to clutch allowed other than springs. No clutch coolers allowed.
Starter: Recoil starter must be retained, as produced and intact. Starter may be rotated.
