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Liquid insanity: putting 2500hp to the water

29 June 2017

There’s a lot more to performance V8s than just land-based contraptions, and if you really need proof of that, we’ve got just that in the latest issue of NZV8 [Issue No. 147]. Grand Prix hydroplanes are the product of almost 100 years of evolution in race boat design, incorporating supercharged 512ci powerplants pumping out 2500hp.

That evolution wasn’t just spent on developing mega-power engines that can stay alive on such a demanding surface, but in designing a boat structure that can stay right-side-up! As the water is never perfectly flat, the pilots must constantly adjust the aerodynamics of the boat to keep the front down while keeping watch for any wake in the water, all while trying to manhandle such a machine around a two-kilometre oval course in a counter-clockwise direction.

The GP Hydroplane class within New Zealand is largely a family affair, with the top boats all driven by the Lupton family from Waverley — Warwick, Ken, and Jack Lupton, and cousin David Alexander. 

Competition is incredibly fierce and unforgiving, and crossing the line first isn’t something that comes easy with these boats. The engines don’t share many characteristics with their land-based relatives. Everything makes successfully campaigning a GP hydroplane a mechanical challenge. The engine set-up on the hydroplanes consists of a 512ci big block, built around a cast-iron block with 4½-inch bores, topped with 18-degree Big Chief heads. Boost comes from a 14-71 supercharger with 120-degree rotors, running anywhere between 20 and 25psi of boost. On a diet of methanol, these motors are good for up to 2500hp. 

Keeping the beating heart at peak performance under racing conditions is no mean feat, considering the stresses and strains under which it is placed. The boats’ land-based counterparts have the luxury of a smooth ride on tarmac rather than the battering a hydroplane experiences while dancing across the water. However, the sheer excitement, both visually and aurally, should be more than enough to secure the GP Hydroplanes a spot in any V8 lover’s heart. 

We’ve got a full feature on the Lupton family Grand Prix Hydroplanes in the latest issue of NZV8 (Issue No. 147), available in stores or online here. Event dates for the 2017–18 Hydro Thunder Grand Prix Hydroplanes season are yet to be announced. Keep an eye on to find out more.