Engines — By
Patrick Sciacca — January 2001
|General Motors’ new Vortec 8100 V-8 is a combination of tradition, power, and technology. And it may well power your next boat.|
The name General Motors is as ubiquitous in America as the term dot-com. It’s everywhere: in your car, on television, and around the water cooler. If it has to do with personal transportation, GM probably plays a part in it.
But while people perceive GM as an automotive giant, it also enjoys a long history in the marine-engine field. Back in 1958 the company offered a 283-cubic-inch, 185-hp Chevy V-8 that was used by Owens/Flagship, Chris-Craft, and Crusader. This was the engine that started General Motors in the marine market, and the company has been a leader ever since. After more than 30 years of experience designing, building, and applying engines for boats, GM Powertrain, the division that sells automotive engines to nonautomotive OEMs (original equipment manufacturers), broke new ground when it introduced electronic fuel injection to its marine engines in 1991. For 2001 the division expands on its history of technological innovation and high quality with a new heavy-duty gasoline V-8 called the Vortec 8100. This is the basic engine that companies like Crusader, MerCruiser, and Volvo Penta will adapt for application in the boats you’ll see in dealer showrooms this year. The 8100 comes in two versions, both using GM’s latest electronic control module (ECM) technology.
The 8100 was borne out of GM Powertrain’s earlier 7400, the familiar and ubiquitous 7.4-liter V-8. The 8100, which displaces 8.1 liters, shares the same bore as the 7400: 4.25 inches. A longer stroke, 4.37 inches compared to 4.00 inches, gives it the added displacement. This is an unusual strategy in high-performance engines, where increasing bore is the preferred method, but GM chose it because a longer stroke typically translates into more torque and better durability.
The base Vortec 8100 V-8 engine offers a maximum of 375 hp at the rated 4600 rpm. According to GM you’ll get maximum torque, which is 490 lbs-ft, at 3200 rpm, a popular cruising speed. The high-performance version offers a maximum 420 hp at the rated 5000 rpm, and maximum torque is said to be 505 lbs-ft at 4000 rpm.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.