Validity

[GUMP]

Somebody screwed up! The bearing is a part of the assembly.

This is also from the NHRA site.

NHRA updates stock replacement piston list and policy
11/29/2006

NHRA has announced an amendment to Section 5A of the 2007 NHRA Rulebook entitled ?Stock Cars.? The amendment relates to the newly released Stock Replacement Piston Acceptance List and reflects a change in enforcement procedure. Along with piston specifications and weight, each engine application on the list will also have a Minimum Assembly Weight that will be used for enforcement. The Minimum Assembly weight is the total of the piston, pin, rings and connecting rod.

Effective Jan. 1, 2007, a competitor's rod and piston assembly will be weighed (without bearings) and checked against the posted Minimum Assembly Weight from the Replacement Piston Acceptance List. The weight of each component will no longer be a factor, as long as the assembly meets the Minimum Assembly Weight as posted on the then-current Stock Replacement Piston Acceptance List. However, the list will also include a connecting rod weight, piston pin weight and piston ring(s) weight showing how NHRA calculates the Minimum Assembly Weight. Competitors need not match each individual component weight provided the Minimum Assembly Weight is met and provided all other applicable rules are met. All other specifications listed, such as compression distance, distance from top ring to flat of piston, etc., will still be enforced.

All values listed as ?minimum? or ?maximum? reflect the absolute minimum or maximum NHRA accepted limits. There is no tolerance on any minimum or maximum value or dimension. As with any other minimum or maximum dimension in the NHRA Rulebook, latitude or tolerance must be provided by the builder to ensure legality in the field. Pistons must still be accepted at NHRA Headquarters in Glendora, Calif. , must still have the correct number and ID, and overall configuration must remain unmodified from the accepted sample. Pistons may be lightened to achieve minimum assembly weight, but ?normal? balance procedures must be used. Therefore, techniques such as cutting the piston skirt, cutting valve reliefs, or otherwise changing the configuration of the piston from its ?as accepted? state, are prohibited. (Milling the underside of the piston head is permitted.) Gas porting of any description is prohibited. Dome height and/or dish depth dimensions are still available in the Engine Blueprint Specifications.

Any questions or comments should be directed to the NHRA Tech Department in Glendora.


I would of been just as happy if they had allowed the light stuff to slide, but this is the published rule.

Daren