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NKA Rules for Clones

2022 DUCAR 212 RULES

1. Engine must be factory rated Ducar 212cc and run-in box stock configuration. All parts must be stock OEM
factory production parts unless otherwise specified in these rules. No alteration, cutting, grinding or
machining of any parts. No sandblasting, tumbling or polishing of any kind. This is strictly prohibited. All
parts are subject to be checked by a known stock part if in question. No reading between the lines. If it is
not specifically mentioned in these rules, then it MUST remain stock.
2. Gas: 87 octane pump gas only. (Track to supply test sample.)
3. Block: Stock OEM Ducar 212 block with no machining allowed with the exception of cylinder clearance.
Maximum bore size 2.758” 0 piston pop up allowed.
4. Cylinder Head: No machining permitted on gasket surface and absolutely no porting of any kind.
Maximum intake valve head diameter 1.062” +- .005” Maximum exhaust valve size .946” +- .005”
Minimum depth from gasket mating surface to combustion chamber between valves it .485” +- .010” (for
reference only.) The seats must be stock and can have the 3 angles of 30/45/60 as from the factory.
However, you may not attempt to excessively sink the valves in an effort to increase airflow. Stock OEM
graphite style head gasket only. Minimum .045” thickness. No sealer.
5. Piston & Rings: Stock OEM dished piston with valve relief on exhaust side only. Maximum size 2.7565”
measured at the bottom of the skirt. Stock OEM rings. No altering of the rings allowed, especially the oil
6. Rod: Stock OEM cast connecting rod only. Rod may be honed for oil clearance only. No rounded or broken
edges. No billet rods allowed.
7. Crankshaft: Stock unaltered OEM crankshaft. Governor gear must be installed in stock location. Max
stroke 2.163 +-.010”
8. Flywheel: Engine must run PVL aluminum die cast flywheel only. No cast iron OEM flywheels. Must utilize
stock unaltered timing key. Stock OEM unaltered ignition coil.
9. Camshaft: Must run stock OEM camshaft. Base circle size .865” +.010 - .005” Maximum Intake lift .225
Maximum In duration at .050” = 210 Maximum In duration @ .200 = 75 Maximum Ex lift .232” Maximum
Ex duration @ .050” = 212 Maximum Ex duration @ .200” = 84 All checks to be taken at the push rod.
10. Valve Train: Maximum valve spring wire diameter .079” Stock OEM springs must be used. (15lb @ .850”)
Valve seal allowed on intake side only. No shims allowed. Stock OEM push rods must be used with a
maximum length of 5.900” +-.010” Stock unaltered lifters and spring retainers to be used. No lightweight
11. Carburetor: Stock OEM Ruixing carb only. Carb must be completely stock. No machining of any kind.
Maximum venturi .615” and minimum venturi size .608” Carb bore maximum .750” Stock E-tube with a
maximum of 20 holes. 1.092” minimum length and minimum outside diameter of .154” .066” maximum
hole through the E-tube. Butterfly minimum .037” Minimum throttle shaft .115” Minimum screw length
.305” Phenolic spacer must remain stock. Maximum pilot jet size .018”(.019”no-go)and must use both o-
rings. Maximum main jet size .029” (.030” no-go)
12. Air Box: Stock OEM air box must be used and in stock unaltered form only. Air must enter through the air
filter only. Any open unused holes must be plugged. Stock OEM air filter with foam sock must be used.
13. Muffler: Stock OEM muffler in unaltered form must be used. If any doubts about the integrity of the
muffler should arise, simply cut the muffler in two, to determine legality by comparing to known stock
14. Governor: Governor gear, arm and linkage must remain intact and functional. Track may require engine to
be free revved on the stand to a certain RPM to determine if governor is properly functioning. (5500 rpm
max for example) It has been our findings that some engines surge and some will not. We do not require
the surge because in stock form the engine will perform best at 5000 rpm or less.

15. Gas Tank: Stock tank should be removed and an auxiliary tank mounted in the floor pan should be used. A
top plate and fuel pump are allowed with the pump be pulsed off the valve cover only. The vent tube can
be unplugged and up to 4 - 1/8” holes in the fuel cap for venting.
16. Low oil shutoff can be disconnected. No taping or decals added to the recoil in an attempt to block off air.
17. Chain guard, throttle linkage, top plate and fuel pump are the only aftermarket parts allowed on the
18. There is no longer a claimer rule. The engine in question must be protested by a competitor or subject to
tech by the track if the promotor/tech deems necessary. The protest is $175 acceptance fee is $50.
19. If there is any doubt as to the legality of any part on a Ducar 212 engine, the competitor has the right to
file a protest with the track/official. The part in question can then be shipped to DynoCams for review.
Please include contact information for the promotor and we will contact the promotor with our findings
on the legality of the part in question in a timely manner.


Super stock rules

*Any 6.5 factory rated small footprint engine up to 212 cc
Various Clone 196 , ducar 212,hemi and non hemi predator 212, 196 and 212 Tillotson engines ect.
Animal can be used but it would be the most pricey option.
6” Calipers, 1” drop dial or digital indicator and sufficient bracket to hold indicator over pushrod and valve retainers. Degree wheel for duration. No go or Pin gauge set for carb. Cc burette for compression
•Simple and to the point with no visual judgments calls. Yes or no on dimensions and stock parts comparison

*No coatings of any kind inside engine or on engine components. Exhaust pipe only can be coated.

*All “as cast and factory” blocks and cranks. No billet cranks. Minor grinding for cam,rod, and crank clearance allowed on crank cam or block. No excessive lightening. Welding on short block/sidecover for bracing and/or repair is fine.

*Bore and Stroke are to be stock per that engines factory specs. Over bore for a rebuild is permissible.

212 cc style engines
2.770 is Max bore
2.165/55mm is max stroke
+\-.0098 / .25mm on stroke

2.688 is stock bore
2.728 is max bore size (.040 over)
Max stroke for animal is 2.200 +\- .010

Clone blocks can be bored to same specs as 212cc

*Billet sidecovers without cam bearings are legal.

*Any factory Stock length billet rod allowed with stock flattop or stock dished 3 ring piston and stock compression height (per factory specs for that particular engine choice). +.01,.02,.04 rods allowed to get correct deck height as long as compression height on piston is still stock and unaltered.
No aftermarket pistons

*Stock factory valves. No aftermarket stainless steel or titanium valves. No tech on visual appearance but must be stock diameter.
Clone heads can be fixed to allow 27/25 mm combo

27mm intake and 25mm exhaust +\- .25
1.062 intake and .984 exhasut +/- .0098

*3 angles on the seat only, 1 angle on the valve

*Valve seat and bowl max inside diameter
Intake. .975 24.76mm Max
Exhaust .875 22.22mm Max
Measuring in 3 spots if no go is not available.

*Any aluminum or machined steel flywheels are legal. !!!No stock cast flywheels!!! 3.3 lbs min weight. No super light finless flywheels

*Cam is .276 max lift at the pushrod
250* duration at .050 max
.276 max lift at the valve
No billet adjustable cams

*install height is non tech

*10.8lb 18lb 22lb or 26lb single wound springs.
No dual or high tension single wound springs.
Compare to a known unaltered 10.8/18/22/26 lb spring.
(Length, wire diameter, outer diameter, coil spacing)

*aftermarket spring retainers allowed.
Aluminum or steel. No titanium

*Stock style stamped rockers only, ratio non tech but must be unaltered ball area and slot size
Grinding tips for lift is legal
Polishing of ball area and tips allowed.

*Studs and rocker nuts non tech

*Pushrod are non tech, no titanium

*Stock style flat lifters and must be magnetic
*No welding or epoxy added to heads as cast. Inside or out.
Porting is allowed.
AKRA porting tools for port size no go gauge for D shape Port Entry only
No tech on seat blending or touching valve guide

*Head gasket thickness non tech

*No piston pop out

*14cc minimum chamber volume
Check Cc like a stock clone

*Intake manifold non tech. Pulse from intake or crank case is allowed.

*Hl series Tillotson carbs with 1.000 max throttle bore and .900 max Venturi

*Gas or Methanol allowed

*Exhaust is non tech just needs to be braced, wrapped in a safe manner with a blunt or flared tip, trumpet, washer ect.
*Must have fuel pump and throttle cable kit mounted in safe working manner.

Tech procedure order
  • Fuel
  • Carb
  • Lift at retainer and pushrod
  • Duration
  • Slide rockers off and check CC
  • Ports, springs, and valves
  • Confirm stroke and bore per engine
  • Check for stock crank and 3 ring piston
  • Flywheel





Buy fuel at the Kangaroo Express in Kenly

Kangaroo Express
402 S Church St
Kenly, NC 27542