Burris National Speedway Series – 2003 Season Rule Book


SECTION 9 - F200 TECHNICAL SPECIFICATIONS

9.1  Approved, commercially available, single cylinder air-cooled overhead valve engines. 200 cc's maximum displacement. See Chart for approved engines.
9.2 Block, Cylinder Head, Crankshaft and Side Cover: Must be approved OEM items.
Cylinder head, block and side cover external surfaces may be machined to remove
excess material from mounting bosses, cast in brackets, etc that are no longer in use.
No external machining allowed to enhance performance.
9.3 Exhaust System: See rule 8.3
9.4 Carburetor: Any commercially available butterfly type Tillotson HL series carb. Maximum venturi diameter = .790" Seniors and Jr lll, .735" for Jr ll and .635" for Jr l. Metering holes non-tech. Filter cups, adapters and air filters non-tech items. Pulse type fuel pumps permitted. Maximum throttle bores are as follows; .790" carbs = 1.010", .735" carbs = .885" and .630" carbs = .820".
9.5 Fuel: See rule 8.1 and 8.1.2
9.6 Intake manifold: Aluminum only. Maximum mean inlet tract length is 2". Length
determined by adding the longest and shortest tract distances (flange to flange) together
and dividing by 2.
9.7 Connecting Rods: Aluminum only. (Fasteners and inserts/bushings excluded) Stock
length (plus or minus .010") to be maintained. See chart for specific details.
9.8 Pistons: Any aluminum three ring, flat top or dished piston. (No domed or pop up
types) Rings and wrist pin non-tech. OEM wrist pin diameter to be maintained. See
chart for maximum bore size and wrist diameter for a specific engine.
9.9 Crankshaft: Standard OEM item with stock stroke length (plus or minus .010").
Thermal treating and shot peening permitted. Minor grinding for camshaft clearance
permitted. No other alterations allowed. See list for specific stroke details.
9.10 Flywheel and Ignition Coil: Aftermarket or OEM flywheels permitted. If OEM flywheel is used it must be unaltered and meet minimum listed weight and stock OEM coil (ignition system) must be used. Approved aftermarket flywheels only may be used. Spec diameter and weight as follows; 6.75" +/- .25"dia. X 4.75 lbs +/- .75 lbs. When using aftermarket flywheels, any approved OEM F200 coil may be used on any engine. (i.e. Briggs coil on a Honda, Tecumseh coil on a Kohler, etc) External coil modifications to facilitate mounting are legal. Coil mounts, flywheel key, spark plug boots and plug wires are non tech items. Approved flywheels are the ARC models 6606 and 6608 and the UMMF model FA-100 and the FS-1001.
9.11 Cylinder Head: Original factory casting only. Two valves maximum and must maintain original location, (listed spacing and angles). Porting and grinding permitted. No external addition of metal to enhance performance allowed. Stock spark plug size and location to be maintained. Minimum combustion chamber volume when mounted on engine @ TDC is 24 cc's using prescribed procedure as noted in rule 8.5. This is to be done after the event and when the engine has cooled down to a reasonable
temperature.
9.12 Valve Train: Steel valves only. No titanium components allowed. Intake 1.080"
maximum, exhaust is .990” maximum. Stock OEM rocker arms and rocker plates only.
Rocker arms may be welded or reinforced for strength. No other alterations to original
configuration permitted. Flat tappets only, must be stock appearing. Push rods, push
rod guide plates, retainers, springs, keepers, rocker adjusters, etc, non-tech.
9.13 Camshaft: Maximum (actual) lift .275" measured at valve. Cam and crank gear
non-tech. This is to be done after the event and when the engine has cooled down to a
reasonable temperature.
9.14 Fasteners: Non-tech, but must remain in original location. Heli-coils, studs, etc
allowed.
9.15 Gaskets: Non-tech.
9.16 Lubrication system: Must retain splash type oiling system.
Approved Engines and Specifications
   
Make: Briggs Honda Kohler Tecumseh Yamaha Notes
Model: Intek 5.5/
Animal
GX200 C6 XKE OHV 5.5 YF200 R1 Animal w/5.5
Intek crank
allowed
Bore, Std: 2.688 2.679 2.638 2.797 2.598 Standard Bore
Bore,
Max:
2.760 2.709 2.783 2.833 2.809 Maximum
allowed
Increase: 0.072 0.030 0.145 0.036 0.211 Increase from
std. bore
Stroke: 2.040 2.125 2.008 1.938 1.968 Standard Stroke
+/- .010
Rod
length:
3.375 3.303 3.425 3.484 3.324 Cntr to Cntr.
Tolerance is
+/-
.010
Rod
length:
2.514 2.358 2.540 2.703 2.459 Inside length
Wrist pin
dia:
0.625 0.708 0.550 0.563 0.630 Tolerance is
+/-
.0025
Rod
journal
1.098 1.180 1.218 0.999 1.101 Tolerance is
+/-
.0025
Flywheel 5.75 lbs 5.75 lbs 8.1 lbs 7.0 lbs 6.5 lbs Approx. weight
in pounds
Valve
spacing
1.382 1.219 1.380 1.250 1.181 Valve angles are
90º from deck

 

BACK