NHRA Stock Replacement Piston Question

[SSDiv6]

Originally Posted by Bernhard

Hi.
When a piston is submitted to NHRA for review is it an exact copy of the original?
specifically ring land design?
Thanks
Bernhard

Although some non-compliant pistons are out there, in a nutshell, Yes, they should mirror the OEM piston according to the rule book.

Compression distance must be identical to OEM.
Ring land location must be in the same location and distance.
Ring groove width must be OEM.
Dome size, (height/volume must be OEM)
Valve reliefs must be the same size and depth.