526-horsepower V8 to make Shelby GT roar

The radical 526-horsepower V8 that will power the Shelby GT 350 Mustang thundered to life for the first time in public outside Ford Motor Co.'s performance engineering center in Allen Park just outside Detroit Tuesday.

It's the most powerful naturally aspirated street-legal engine in Ford's history.

The all-new 5.2L V8 has a number of features normally seen only in race cars and exotic sports cars from the likes of Ferrari and Porsche. Designed to rev up to 8,250 rpm – nearly four times the revolutions per minute a run of the mill V8 might hit at highway speed – the engine sets several new marks for production engines. It's the highest revving V8 in Ford history.

Prices for the Shelby GT 350 Mustang are expected to start at $49,995 when the super-Mustang goes on sale late this year.

The V8 features a flat-plane crankshaft, bigger engine valves and unique air intake and exhaust systems to generate extraordinary levels of power, including 429 pound feet of torque at 4,750 rpm. Peak horsepower comes at 7,500 rpm.

The engine's horsepower output of more than 100 hp per liter of displacement is almost unprecedented for an American V8 that doesn't use turbo or supercharging.

"Airflow is key to more power," engineer Adam Christian said. In addition to bigger valves and new air intake and exhaust passages, the unusual crankshaft helps the engine use air more efficiently and rev at higher rates. The flat-crank leads to more vibration, however. That's one of the reasons you seldom see them in production engines, where smooth running is prized. The engine's cylinders fire in an unusual order, contributes to a very distinctive sound. The Shelby will be the only engine in production with a front-mounted flat-plane crankshaft, setting it apart even from exotic cars with six-figure price tags.

Under development for about three years, the engine shares virtually no parts with the 5.0L V8 that powers the Ford Mustang and F-150. It will be built on a special, low-volume line at Ford's engine plant in Romeo, north of Detroit.

Ford set out to develop an engine with exceptionally low weight, high power and quick throttle response for the latest version of the GT 350, a model that goes back to the high-performance Mustangs legendary racer Carroll Shelby developed with Ford in the 1960s.

Ford will build the Shelby GT 350 alongside other Mustangs in Flat Rock, a few miles south of Detroit.

Contact Mark Phelan: mmphelan@freepress.com or 313-222-6731. Follow him on Twitter @mark_phelan.