The NHRA Technical department has recently evaluated numerous alcohol heads during various events as well as gathered information from manufacturers in order to develop additional specifications for the heads currently running in Top Alcohol Dragster and Funny Car categories. These new specifications which are listed below will become effective January 1, 2015. You can also find these specifications posted on www.NHRARacer.com/NHRA Accepted Products/NHRA Accepted Product Specifications.
|
Chevy / MBR |
Chrysler / Hemi Heads |
Chrysler / Veney Heads |
481X |
Bore Centers |
4.84” max |
4.80” max |
4.80” max |
4.84” max |
Intake Valve Max Size |
2.60” max |
2.60” max |
2.60” max |
2.45” max |
Total Combined Intake and Exhaust Valve Size |
4.60” max |
4.55” max |
4.70” max |
4.45” max |
Intake Valve Angle |
24˚ ± 1˚ |
20˚ ± 1˚ |
32˚ ± 1˚ |
12˚ X 4˚ ± 1˚ |
Exhaust Valve Angle |
24˚ ± 1˚ |
23˚ ± 1˚ |
21.5˚ ± 1˚ |
6˚ X 4˚ ± 1˚ |
Lifter Bore Center to Center |
2.00” max |
2.00” max |
2.00” max |
2.300” max |