The so-called SB4 7.0 engine is made for the crate engine market. The company says it targets customers who want to install it in "pre-1968 muscle cars, street rods and an array of road, track and off-road competition vehicles."

Mercury Racing also makes an even bigger engine for automotive use, the QC4 model — a 9.0-liter, DOHC V-8 with twin turbochargers that produces up to 1,350 hp.

"For those occasions when 775 hp isn't enough," Foulkes said jokingly. He is also in charge of Mercury Marine product development.

The marine unit is a sizable manufacturer, even without re-entering the car market. In 2016, it sold $2.4 billion worth of marine engines, up 5 percent from 2015. The company has more than 6,000 employees. Engine manufacturing is at two plants in Fond du Lac, with outboard engines also made in China and Japan.

So far, the crate engine business is tiny. In one shipment, for instance, Mercury Racing sent a customer 10 engines for cars that are "still in development," said Erik Christiansen, general manager. He wouldn't say who bought the engines.

Rick Mackie, senior marketing manager for Mercury Racing, said Mercury hasn't had any conversations with General Motors about future Corvettes. He said Chevrolet is rumored to be considering a midengine model that could have DOHC and four valves per cylinder, which would play to Mercury Racing's experience.

"I would think we would at least have the conversation," Mackie said. "But we haven't yet."