In 1985, the Outboard Marine Corporation (OMC), which was the parent company of Evinrude and Johnson, introduced a new 3.6-liter two-stroke V8 engine with carburetion. The 3.6 GT and 3.6 XP engines were rated at 275 horsepower, but it’s said they produced at least 300 horsepower at 6250 RPM. These engines consumed a lot of fuel (91 octane) and were designed to run at full throttle, making them unsuitable for most recreational boaters.
However, they were built for speed and were responsive to tuning. In 1989, a 3.5-liter version reached 10,000 RPM and set a world record speed of 176.556 mph for outboards, which still holds today. In 1988, the engines were increased to 4.0 liters and became the GT and XP 300 V8s, produced until 1995, along with some 275 and 250 models. The V8 two-stroke eventually became obsolete due to the advent of fuel injection, which made similar power output possible with a smaller V6, as demonstrated by Mercury.
The 300 models were formidable machines, with eight carburetors and a weight of 555 pounds. Despite the noise, some people have attempted to use them for street use or mount them on wheels. About five years ago, a man named Shane Stenton built a sand rail powered by an XP 300 engine. In the fall of 2022, a Swedish company called VM Performance made headlines with an even more impressive version, featuring large custom-made expansion chambers and a sound like a giant chainsaw.
