Car Specifications
Written by Administrator   
Tuesday, 22 November 2011 20:25

These specifications provide the framework for LMMC officials to inspect racecar. In addition to interpreting and enforcing these specifications, LMMC officials are authorized to make such other determinations or take such other actions as they determine to be necessary to promote the best interest of micro sprint racing, including, but not limited to fairness and prompt finality of completion and results.


Table of Contents











A. There will be five (5) racing classes:
Sportsman, 125cc 2 cycle, 250cc 4 cycle, 250cc 2 stroke, 600 4 cycle
B. Lanco is a member of the U6SA organization, in addition to the specs listed below, all 600 cars must follow the 600cc Micro Sprint Universal Rules defined by the U6SA.
A. Car and driver weight at completion of race shall be 600 pounds or greater, weight for the 600 class will be 775 pounds or greater.
A. Single cylinder engines only are allowed for all classes except twin cylinder engines are allowed for the 250 four stroke class and 4 cylinder engines for 600 class.
B. The sportsman class allows the following engines:

1.      Spec 250cc liquid cooled engine

 a. The following are the approved engines:

u 1992 to 2001 Honda CR 250cc

n  Bore x Stroke: 66.4mm X 72mm

u 2002 to 2007 Honda CR 250cc

n  Bore x Stroke: 66.4 mm x 72 mm

b.  Cylinder and head must hold a minimum of 20.5cc of fluid for a compression ratio test.

u The volume is measured with the head bolted to the cylinder of a race ready engine, when the piston is at TDC (Top Dead Center) and measured to the top of the spark plug threads.

c.  The engine must be stock in configuration and appearance with no internal or performance modifications, other than those modifications listed below: (all other internal or performance modifications will be considered illegal)

1)      Any carburetor

2)      Any pipe

3)      Any fuel pump

4)      Any two ringed piston manufactured as an OEM replacement for the approved engine; both rings must be used.

5)      Power valves may be removed and replaced with a plug.

6)      Clutch linkage and kick-starter assemblies may be removed and plugged.

7)      Remove and weld aluminum lug by chain sprocket on engine side case.

8)      Remove and weld aluminum casting on case half where carburetor rests.

9)      Aftermarket covers may be used for the: clutch cover, ignition and/or power valve.

10)  Clutches may be removed and clutch hub may be altered or replaced with an aftermarket hub.

11)  Cylinder modifications any internal modifications that do not alter the appearance of the outside of the cylinder.

12)  Any Honda straight or angled carb insulator boot.

a)      Modifications for carb retention are allowed as long as they do not enhance performance.

13)  Stock Honda Head, no inserts.

a)      Head cutting is allowed – must meet 20.5cc fluid test.

14)  The clutch side may be sealed from the gear case and an additional fill plug may be added.

d.. Additional clarifications:

1)      Stock Bore

2)      Stock Stroke

3)      Stock OEM Crank and Rod, no modifications

4)      No base or spacer plates

5)      The following stock OEM gaskets must be usedand may not be modified: Head, Base and Reed

a)      Only 1 of each gasket may be used and no additional Head, Base or Reed gaskets may be used

6)      Ignition must be stock appearing, any plug wire, spark plug or spark plug cap may be used

7)      Stock OEM reed cage from a 1992 to 2007 Honda CR250cc model year engine –no modifications

8)      No reed spacer

9)      No case porting

2.      270cc Air Cooled Engine

a. Engines marketed as an air-cooled 250cc displacement or fewer engine.

b. Maximum piston displacements shall be 270cc

C. There will be only one engine permitted per car.
D. Maximum piston displacements shall be:
  1. 125cc engine – 8.24 (or 135.00cc)
  2. 4-stroke 250 engine - Stock bore, stock stroke, stock cylinder height, no spacer plates, no thick gaskets, stock configuration crank and rod. Any work on heads and valves is allowed. The existing modified (4 Stroke 270 engines) engine owners may run with 125cc class; Fuel injection is permitted, if fuel injection is used, the motor must remain stock bore, stock stroke, stock cylinder height, no spacer plates, no thick gaskets, stock configuration crank and rod, and have OEM throttle bodies.
  3. 2-stroke 250 cc engines – 16.4754 (or 270cc)
    450 cc stock bore & stroke
  4. 600 - see the Engine Specifications defined by the U6SA for piston displacement.
Note: To find cubic centimeters (cc) multiply Bore X Bore (mm) x3.14 x stroke (mm) divide by 4000.

E. Titanium cranks are illegal. (Protest able only)


A. Mufflers are required to provide a sound limit of 100 dba maximum 4-2stroke must provide muffler at sound limit of 104 dba maximum

A. All cars must be rear wheel drive B. No open drive shafts will be allowed. C. Chain guards must be installed on all cars where chains are exposed to the driver. 

A. Wheelbase- 70 inches, maximum – 56 inches, minimum B. Width (at tire sidewalls) 60 inches maximum, 40 inches minimum.

  1. There is no width rule for 600cc class.
A. Roll cages
  1. Roll cages are mandatory
  2. There must be a minimum 12 inches opening between the top rails:
  3. The material must be a minimum of one inch O.D., .083-inch wall thickness: anything 1.25 inch O.D. and over .065.
  4. All roll cages must have at least a 2 inch gusset at all butt joints.
  5. Roll cages with front down tubes must extend forward from the top of the cage to the front shock mounts.
  6. Roll cages must be attached to the frame (minimum of six points)
  7. Under no circumstances may the helmet of a normally seated driver extend above the roll cage.
  8. Roll cages must be high enough that the driver’s helmet, when seated in normal position, is three (3) inches below the roll cage. Otherwise a wing will be mandatory.
  9. Full roll cage extensions, including gussets, if extension is more than five (5) inches high, are allowed as required.

B. Side Bars:

  1. All cars must be equipped with horizontal bar on the right side between the cockpit uprights and a horizontal bar, or a smith bar on the left side. 600cc class frames only may run without these bars if they have an approved manufactured full containment high back seat including head and shoulder restraints.
  2. Construction to be of the same material requirements as roll cages,(one inch minimum on both sides).

C. Nerf bars and bumpers:

  1. All cars must be equipped with nerf bars through out the race.
  2. Bars must extend at least to the middle of the tire, but not beyond the outside of the tire.
  3. Cars must be equipped with bumpers extending beyond the front and rear tires through out the race. No blunt ends, no flat bumpers, must be “V” shaped on the rear.
A. Wheel diameter: 10 inch maximum B. No dual wheel cars will be permitted. C. All cars must be equipped with functional rear brakes. Front brakes are optional.
A. No cable steering allowed. B. Direct steering specifications:
  1. 5/8 inch minimum steering column shaft
  2. 3/8 minimum heim ends

C. Quick release steering wheel optional D. Only foot operated throttles, with positive return are permitted. Physical challenged equipment acceptable

A. All cars must have complete bodies (normal sprint car). No extending panels on hood or tail. Lower side panels must extend to the rear of seat and/or seat belt mounts and forward past throttle and/or brake. Sail panel will not extend past rear down tube and no flare on rear edge of panel.
B. Painting and numbering (guidelines only – not a tech item)

  1. All cars must be painted an attractive color or colors
  2. A six-inch minimum height car number is to be painted on both sides of the tail.
  3. A 15-inch minimum height car number is to be painted on top of the wing, angled towards the right, from the front of the car.
  4. A 10 inch minimum car number is to be painted on both sides of the wing.
  5. Any letter as part of the number must be half the size of the number and appear at the rear of the number.

C. Firewall

  1. All cars must be equipped with a firewall between the driver and the engine compartment. Minimum thickness specs are:
    Steel 24 gauge (0.0239 inches), Aluminum 0.050 inches,
    Fiberglass or plastic 0.095 inches.

D. Floor pan

  1. The floor pan must come to a point just rear of the front axle or tie rod to the front edge of the driver’s seat.
A. Any material used for the purpose of adding weight must be Welded or bolted to the car structure. B. No liquid or loose ballast will be permitted.
A. Only methanol alcohol and water (and oils for lubricating purposes) are legal fuels. B. Approved legal additives are posted in the pit shack C. Exterior fuel tanks will be permitted and are to be made of high impact material only. D. Only one fuel tank per car E. Only natural aspirated fuel systems allowed (carburetor)
  1. Forced fuel induction or superchargers of any type will not be allowed.
  2. The four-stroke class may use a fuel injection system if it comes an an OEM standard for that motor yeat and model. The engine MUST stay standard bore, stroke and the throttle body must stay stock. The engine may not be modified to the 270 cc maximum limit,
A. All wings must be all metal or lexan construction externally B. All mounts and adjustments must be outside of roll cage C. Wings sizes:
  1. Wings cannot exceed 12 sq. ft. (1728 sq. in.) this will include all flat or tapered areas viewable from the top.
  2. Maximum length of wing panel is 54 inches.
  3. Inside side panel may be a maximum of 24 inches high
  4. Outside panel may be a maximum of 24 inches
  5. Panels must be parallel and not obstruct the driver’s vision.
  6. There will be a maximum of two-inch lip on the side panels.
  7. A front wing is optional, not to exceed 2.5 sq. ft. (360 sq. in.)
  8. Front wing of 600 is not to exceed 576 sq. inches.
A. Fabrication of critical parts, frame, running gear and attached brackets, cowl frame, back rest, fuel tank mount, bumpers, nerf bars, front and rear axles, steering mechanisms, engine mounts, exhaust mounts and roll cage parts must be welded. B. Radiator mounting and locations is optional but must have adequately mounted brackets, no wire ties and must not extend center of rear tires. C. Batteries must be securely mounted and covered. D. Shifters must be in such a position that a driver cannot get his hand near the drive chain or other moving parts when shifting. E. Nothing on the car will be allowed past the outside edge of tires. F. Stop and or tail lights are not permitted.
A. Full five point seat belt, shoulder harness and anti-submarine strap are mandatory.
  1. Safety belts and harness must be attached to the car frame with 5/16 inch (minimum) bolts or securely wrapped around the frame at all times.
  2. Quick release must unlatch both belt and harness at the same time.
  3. All cars must be equipped with approved ant-submarine belts mounted to the frame of the car.
  4. All shoulder harnesses must be mounted so that straps loop over a bar, even with the driver’s shoulders, to a maximum of six inches below the shoulders at all times, regardless of driver changes.
  5. High backed seats will be mandatory, a High backed seat is defined as full backed incorporating a headrest.

B. Car must be equipped with a positive on off fuel valve and operating ignition switch located within easy reach of driver.

  1. On the 600 cars, the fuel valve must be located between the rear of the seat and the tail, and may not be reachable by the driver.

C. Carburetors that protrude into the cockpit must be covered or have a deflector shield installed.

A. Cars must meet Lanco’s weight, fuel wheel base, and motor specifications.

A. All of the above are subject to the technical committee’s interpretation and approval.



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