Although this topic is about car engines used in other forms of transportation, I thought I'd draw your attention to the power of the modern diesel and it's current use in the superyacht field.
The first photo shows a modern MTU marine diesel - model 16V595TE90 that develops 4320kW (5880ps) at 1800rpm
Four of these are installed in the 72.8m (239 ft) Russian owned superyacht PREDATOR as illustrated in the second photo. This outstanding vessel was built by Feadship in the Netherlands in 2008. Maximum speed 28 knots, fuel capacity 183,000 litres, accommodating only 6 guests with 19 crew.