Grand National Hydroplane

Grand National Hydroplane, aka GNH or 7 Litre, is the largest non-supercharged Inboard hydroplane class. Powered usually by big block Chevrolet based engines (up to 511 cubic inches) with an hot rod racing engine(750+ horsepower), the highly competitive GNH's have 150 mph capability and throw 70-foot roostertails, thrilling drivers and fans alike.
Class Specifications
Minimum Length: | 20' |
Minimum Weight: | 2220 lbs. |
Engine: | Big block automotive and marine based racing V-8 engines, up to 511 cubic inches |
Fuel: | Racing gasoline per APBA specs |
Approximate Speed: | 150mph |
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