Cosworth could be making Formula 1 engines once again if official plans are signed off following verbal agreements with partners.
The Northampton-based engineering company has powered cars to 176 Grand Prix wins, but last had a car in a Formula 1 race with Marussia in 2013.
As the sport moves towards simpler and cheaper hybrid engines in line with new regulations, Cosworth are considering making a return to F1.
"I think that we've got sufficient support from the existing teams, and we've had discussions with some, that enable us to make the commitment to proceed," said Cosworth CEO Hal Reisiger in an interview with Autosport.
"More teams committed for a longer term is always better.
"But we have some verbal agreements to partner with some existing and future teams that would enable us to be a sustainable engine partner."
Reisiger said he wants F1 to move away from the heat energy recovery element that has proved so troublesome for current manufacturers.
"We think we are well suited to come back into F1 if the engine regulations should change, and the compelling change has to be with the heat energy recovery [from the turbo] because that is the most expensive and time-consuming element," he said.
"If F1 wants a new engine supplier for 2021 there will have to be some changes on that front."
Asked if he felt Cosworth had the infrastructure to produce an engine that could take on manufacturers of Mercedes and Ferrari's size, Reisinger said: "Yes. It is important not only for the teams that we would serve, but for our own brand that we should not get involved in it if we cannot be competitive.
"We have a great historic brand, we want to protect our brand as much as we want to help people win races, but we do think we can do it."
One scenario that could play out is for Cosworth to help design and build an engine that a manufacturer supports and badges.
With Cosworth providing the engine for Aston Martin's Adrian Newey-designed Valkyrie car, there is already speculation that Red Bull would make an obvious partner.
Reisiger said no decision needed to be made until next year, but if a 2021 comeback was going to happen then it would need to start designing the engine in 12 months' time.
"We would typically start in 2018. I know there is some discussion about moving it ahead by a year, and that would mean working really soon," he said.
"On the LMP1 engine, we went from concept to dyno in 11 months. We happen to be very nimble when it comes to that type of capability.
"I don't know there are that many companies that can move that fast, but we have that."