NHRA Top Alcohol Dragster and Funny Car Cylinder Head Specification Update

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

61530