2015 AKRA Rules Update
Rule Book Changes 2015
Deletions in Red / Additions in Blue NOTE: Sorry guys, when I copied and pasted the red and blue didn’t show up.
Important Note: All parts must be Box Stock factory production parts unless otherwise
specified in this rules manual. No machining or alteration of parts is allowed unless
Delete: all parts will be subject to a comparison to a known box stock part
( when performing a stock part comparison )
Tumbling of engine parts is strickly prohibited. Engine will be teched as raced. There will
also be a $200 claiming rule in place for this engine or $350 if engine has billet flywheel
installed (Track or Series Option). Refusing to accept the claimer will result in immediate
disqualification of competitor along with forfeiture of any points earned to date in class.
Competitor will also not be allowed to compete any longer in that class.
Cylinder Head Requirements:
Must be OEM casting only. Porting and / or grinding are not permitted. Valve seats may have up to three angles, 45 degrees valve face and 30 degrees top relief and 60 degree bottom relief. Add the following here: Cutting of the valve seats allowed to insure proper seal.
The use of Aftermarket FLANGED bolts of similar OEM design (head size, diameter, length and thread length/pitch) allowed as replacement for stock head bolts. No studs allowed … No additional washers allowed.” Breather hole on valve cover may be tapped with ¼” pipe tap to accommodate breather fittings, no over size drilling allowed.
Change To: Stock cylinder bore is 2.67” may be bored to 2.691” maximum.
Solid dowel pin replacement for the side cover to block .317 maximum diameter allowed (Factory stock dowel pin is 8mm or .315).* Dowel pin must remain in the factory position.
Stop arm of throttle shaft maybe filed to adjust for butterfly position. Butterfly – .037” minimum(add thickness. Butterfly screw minimum length .305” , screw must remain stock as produced with no alteration allowed to achieve min length.
Black Phenolic spacer must be flat across entire gasket
mating surface with a minimum thichness on gasket surface of .265”. Deburring of inlet
track allowed to remove flashing . Any attempt of inducting air into the intake port
other than through the carburetor bore is not allowed. Surface finish of phenolic
spacer inlet track, non tech.
Phenolic spacer must be flat across entire gasket mating surface, with a minimum thickness on gasket surface of .265″ (not including gasket). Gasket surfaces must remain parallel … no angle cutting allowed. Center inlet hole is NON-TECH ( size, configuration, finish), but no rifling, grooving, dimpling, etc. allowed. Maximum mounting hole(s) size .300″ NO-GO (checked with .300″+ pin gauge)”. Phenolic spacer/gasket(s) subject to spray test to check for leakage or introduction of air into intake track. ..”
Surface finish of contact area of rocker arm to valve stem ONLY, non tech, to adjust for proper lift running lift. Square tiped rockers allowed.
Shims may be used to achieve .815” Installed height, maximum thickness of shims used .045”, any combination of valve seal and spring shims allowed. Add The following here The ruling on the .045 shim thickness includes the oil seal if used. The valve stem seal has no tech other than it’s thickness combined into the max of .045 to obtain a min of .815 installed spring height..
In other words, the valve stem seal can be used or not used and is no longer a tech item unless used as a shim. Also the rubber inside it is a non tech item.
Minimum thickness of Intake retainer .225” , Exhaust retainer .245”.
Piston and Rings:
Minimum weight of piston 145 grams(must conform to this spec by 4/15,2015). Honing of wrist pin journals permitted … bore surface must remain flat and retain stock configuration edges. Skirt of piston must remain as produced … no chamfering, radiusing or breaking of edges permitted . Up to .010” over pistons allowed.
ChangeTo: Oil hole size .179 ” max, .180″ no go. Minimum weight of rod assembly 133 grams.
Page 50 :
Running lift should be checked in front of the rocker arm on the valve retainer.
Header Muffler Requirements:
“Wennie” pipe silencer end cannot be higher than 14 1/2” from the bottom edge of the block mounting surface. Tech the pipe by placing engine on flat surface and measuring from the flat surface to the bottom edge of silencer, cannot exceed 14 1/2”.
Flange for header maximum thickness of .500” / ½”. Allen bolts of original diameter Allowed. Pro Box Stock header must be of traditional “candy cane” design, silencer must be directed down and towards the rear bumper. Maximum height from top of header flange to top of pipe curve is 10”. Bottom edge of silencer end cannot be higher than 9” from the bottom edge of the block mounting surface. Tech the pipe by placing engine on flat surface and measuring from the flat surface to the bottom edge of silencer, cannot exceed 9”.