If you are going to build a kick ass airboat engine, you need a few things. The first is obviously some horsepower, the second is a deep reservoir of torque, and the third is reliability so you are not gator food out there somewhere in the wilderness. This video is a comprehensive and awesome look at the build of just such an engine. In the typical fashion of the channel, Jeff at Horsepower Monster takes us through the build from the block on up to the end results of dyno testing. Starting with a Dart LS-Next block and stuffing the whole thing full of the best parts in the aftermarket, the engine is a 427ci power maker topped with Prestige Motorsports (the engine builder here) own design LS3 11-degree cylinder heads. Breaking news: they work.
After all is said and done, the engine sits more than 6ft tall on the dyno cart all hooked up. The height will not be a problem in an airboat where literally the sky is the limit. There are two sets of dyno pulls made, one with the supercharger basically at 1:1 with the engine and the second with a little bit of overdrive. Both pulls are made on 93-octane gas and the engine is only pulled to 6,000 RPM which is the max it will see in an airboat.
The power is impressive for both pulls and we agree with Jeff that with some higher octane gas, a little more OD, and some more RPM, they could be way bigger! This is a great video and an awesome engine.