Lifters In Stock Eliminator

[Larry Merk]

It is NOT an UNWRITTEN rule.

Page 21 of the NHRA 2025 Rule Book states "On the other hand, as to performance equipment, it is the general rule that unless optional performance equipment or performance-related modification is specifically permitted by this Rulebook, it is prohibited."

Section 11 covering Stock Eliminator under Camshaft/Lifters makes no mention of changing lifter diameter. Therefore it is illegal to do so.

[Lenny5160_v2]

Originally Posted by Larry Merk

It is NOT an UNWRITTEN rule.

Page 21 of the NHRA 2025 Rule Book states "On the other hand, as to performance equipment, it is the general rule that unless optional performance equipment or performance-related modification is specifically permitted by this Rulebook, it is prohibited."

Section 11 covering Stock Eliminator under Camshaft/Lifters makes no mention of changing lifter diameter. Therefore it is illegal to do so.

Considering how the rule is worded, could it be argued that an increase in lifter diameter is not a "performance-related modification"? As in, the modification should increase strength/reliability, but not performance.

[Stan Weiss]

Originally Posted by Lenny5160_v2

Considering how the rule is worded, could it be argued that an increase in lifter diameter is not a "performance-related modification"? As in, the modification should increase strength/reliability, but not performance.

Remember max velocity is limited by lifter diameter. So a larger lifter diameter lets you use a cam with a greater max velocity. There is a performance increase in doing that.


PS If you look in the Comp Cams Master Lobe List you will see that they have a number of lobe profiles that only will work with a .904" lifter.


Stan