Aston Martin says a decision on whether to proceed with a Formula 1 engine for the 2021 regulations will be made within the next nine months.
Company CEO Andy Palmer has made no secret of his enthusiasm for the 2021 F1 rules, which mandate a simplified version of the current hybrid V6.
Former Ferrari F1 engine boss Luca Marmorini was hired last year as a consultant, and has been working on a feasibility study for Aston.
Aston Martin is the title sponsor of Red Bull Racing, and the companies are partners on the Valkyrie hypercar project.
But Palmer admits Aston will have to prove to itself that it can make a competitive F1 engine before any deal can be discussed with Red Bull, and reckons that will be clear by early 2019.
"We're looking at 2021, so it's somewhere down the road," Palmer told Autosport.
"But if we can't pass the 'it's OK for Red Bull test' then that probably means we're not passing the 'it's competitive' test, and it has to be competitive.
"There's approximately nine months' work in front of us to convince ourselves one way or the other.
"You've got simulation tools and single cylinder work, and that gives you a pretty accurate correlation between the testing world and the simulation world."
Palmer said the F1 project had "gathered momentum" within Aston, but could not become a firm commitment without more clarity on the new rules.
"Nothing's come along that's deflected the probability, nothing's been put in place that says we can't do it anymore, so we continue to do as much pre-study as we can in the context of what we understand of the regulations, which are not fully detailed," he explained.
"We can at least size up the opportunity now.
"The bit that we don't know about the regs is the cost cap, and that's an integral part of our decision to come into the sport or not.
"We don't have money to burn. It has to be a better return, let's say, than straightforward sponsorship, and that's a key part of the decision."
While Aston is expected to team up with a specialist such as Ilmor or Cosworth to create the F1 engine, Palmer is keen his company has direct input on its development.
"It brings authenticity, doesn't it?" he said.
"We have the likes of Luca as a consultant to work with us, and help us through the bear pits.
"He's done it before, he has a lot of credibility, a lot of understanding, and he can guide us.
"It's not easy, we're not looking it from a naive 'It's just an engine' point of view.'
"But we are an engine manufacturer, and we are an engine designer. Our V12 is an example of that, the Valkyrie engine is an example of that, so we're not starting from scratch.
"I fully accept that Honda proves how hard it is. But at the same time you can start to see Honda improving."