Ford's investment follows a turbulent few months for manufacturers, with Vauxhall closing its Luton plant and Nissan pondering whether to build the new Micra at Sunderland.
The investment at Bridgend Ford will create around 500 new jobs and follows the announcement that 3,000 Welsh steel workers are to lose their jobs.
The news coincided with Vauxhall ending months of speculation by announcing that its new Vectra model would be built in Ellesmere Port as part of a £200 million investment.
David Thursfield, president of Ford in Europe, said the company hoped the investment would bring more good news to Wales.
"We are also encouraging major suppliers to come into the region, so for Wales, it is a big plus," he said.
The Transport and General Workers' Union said the investment at Bridgend was a "massive vote of confidence" in the workforce.
Ford's investment follows a turbulent few months for manufacturers, with Vauxhall closing its Luton plant and Nissan pondering whether to build the new Micra at Sunderland.
It also brings some much needed good news to South Wales, hit last week by the news that thousands of jobs were to be axed by steel giant Corus.
Ford last year cut thousands of jobs at its UK plants, including Dagenham, but Bridgend's 1,500 workers escaped the heavy round of cuts.
The V6 engine will power the forthcoming "baby" Jaguar, which is aimed at competing with the BMW 3 series.
Bridgend will produce around 100,000 of the engines every year.
Assembly First Minister Rhodri Morgan said the announcement was a "major coup for Welsh industry."
And, he added:
TGWU Wales leader Jim Hancock said it was a "triumph for partnership".
And, he added: "Ford's decision to manufacture the new generation V6 engine at Bridgend is a massive vote of confidence in its Welsh workforce and a tribute to their skills and teamwork.
It will anchor Bridgend firmly at the forefront of premier engine manufacturing "The creation of hundreds of new jobs at the plant is crucial.
"It displays a commitment to Welsh manufacturing by a world class company."
Mr Hancock said the new V6 power unit would be a prestigious addition to Bridgend's already impressive product portfolio.
"It will anchor Bridgend firmly at the forefront of premier engine manufacture for many years to come," Mr Hancock added.
Mr Hancock praised the teamwork behind the plants bid which swayed the company's decision to invest in Bridgend rather than Cleveland, USA.
"This has been the result of a vigorous and focussed team effort by the Union, Management, Welsh Assembly, WDA and of course the Welsh workforce - an unbeatable Welsh combination."
Ford is set to officially announce details of the investment on Monday morning.