Pat Fry, the former McLaren and Ferrari engineering chief, has joined Manor.
Fry, who hails from Surrey, enjoyed 17 years at McLaren before moving to Ferrari in 2010.
The 51-year-old left the Italian team four years later, but will return to the grid with Manor this season.
"Manor Racing is pleased to announce that Pat Fry has joined the team to provide engineering consultancy as it gets its 2016 challenge under way," a team statement read on Monday.
"During that time, the team will benefit from Pat's considerable experience in various race engineering and technical leadership roles - with Benetton, McLaren and Scuderia Ferrari - to help develop its engineering capabilities."
Dave Ryan, Manor's new racing director, added: "We are extremely fortunate to have Pat on board to help us hit the ground running with our exciting new technical package.
"The aim is to bring performance to the car with effect from the Barcelona tests, then translate that to the race track in Melbourne, to ensure we make the strongest possible start to 2016 and have a good basis for development in the early part of the season."
Fry joins Nikolas Tombazis - also formerly of Ferrari - who Manor last week announced as its chief aerodynamicist.
Manor competed at the back of the field last season, but is expected to be more competitive in 2016 after agreeing a deal with Mercedes to use their engines.
The British-based team, who Englishman Will Stevens raced for last season, is the only team yet to announce its driver line-up for 2016.