butch_mcc
Vice President
Joined: Sat Feb 28, 2009 11:19 pm Posts: 540 Location: Columbus, Ohio Class: Jr. Clone Chassis: Bandit Engine: 4 cycle Clone
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 2014 AKRA Clone engine updates
Rule Book Changes For 2014
Cylinder Head Requirements: Valve seats are of three angles 45 degrees face angle with top relief of 30 degrees and bottom relief of 60 degrees. Header may also be run without gasket, sealer only. Allen bolts permitted on Header to head
Block Requirements: Oil drain hole between lifters ..251” no go. Any type side cover Fastener and lock washer permitted, must be original size. Sealer on gasket allowed
Carburetor Requirements: Side holes in e-tube diameter .036” no go. Stop arm of throttle shaft maybe filed to adjust for butterfly position. Surface finish of phenolic spacer inlet track, non tech. Carb bore at rear of carb, .750” maximum depth. Note: This measurement is taken from the flat surface on the rear of the carb down to the circular ridge. Venturi may be machined to spec. No polishing permitted. All transitions must remain stock in and out of venturi. Choke area must remain as cast
Valve Train: Surface finish of contact area of rocker arm to valve stem , non tech, to adjust for proper lift running lift. Running lift should be checked in front of the rocker arm on the spring retainer. Stock steel/stainless nitrate coated valves only 45 degree angle only both valves with a minimum weight of 21 grams each valve.
Shims may be used to achieve .815” Installed height, maximum thickness of shims used .045”, any combination of valve seal and spring shims allowed. Valve stem seal thickness non tech Over-all length of push rod 5.285” max. ( 9 grams min. weight) Weight check lifters 18 grams min. Minimum thickness of Intake retainer .225” , Exhaust retainer .245”.
Piston and Rings: Piston must be unaltered Box Stock only. (No machining of piston allowed.) Overall piston length 1.935” max and from top of wrist pin to top of piston .580” max. Arrow on top of piston must be pointed toward valves/lifters. Overall length wrist pin 2.100” min, inside diameter .550” max. Top ring and middle ring .115” max width, .060” max thickness. Filing of ring end gaps permitted including oil expander, max end gap .040” Lapping of rings permitted for proper seal Piston ring must be in one piece (unbroken) when presented for tech.
Two top rings must support themselves when placed in cylinder with endgaps facing upwards Oil ring must support piston and rod assembly when placed in the cylinder
Connecting Rod: Length from top of journal to bottom of wrist pin hole 2.375” max and 2.350” min. Honing of journal end and wrist pin hole permitted, those surfaces must remain flat. Oil hole size .172” max, .173” no go New stock Performance cast rod allowed
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