Red Bull could move to build their own engines when Honda leaves Formula 1 after 2021, InsideRacing has been told.

On Friday, the Japanese manufacturer announced the surprise decision to end their F1 operation at the end of next year, seven years after returning with McLaren back in 2015.

That leaves Red Bull and sister team AlphaTauri potentially facing the possibility of having to re-partner with Renault from 2022, the same company they parted from at the end of 2018, as the French manufacturer will be the only supplier without customers from next season.

However, a source has told InsideRacing.com that the Austrian drinks giant may look to avoid that by buying the current Honda engine operation near their factory in Milton Keynes and simply create their own power units.

Doing so would avoid Red Bull becoming a customer of one of the three other current engine makers, all of whom have their own works teams.

It would allow the team to continue using the current Honda unit, which has improved significantly in recent years, as a benchmark for their own brand engine going forward.

And Red Bull also wouldn't have to worry about having to adapt their 2022 car to fit a new engine design.

Costs would obviously rise, but the new budget cap may well offset that, with engine development not part of the $145m limit.

For Honda, selling their Milton Keynes operation may help recoup some of the massive investment they've put into F1 since returning in 2015.

It would also mean the years of work put into their current engine would not be a waste as it would likely continue to race albeit under the Red Bull name.

So there's plenty of reasons then why the move would make sense for Red Bull going forward and, having been linked to building their own engines before this certainly represents the best opportunity to do so.