Zak Brown has shot down rumours that McLaren could solve their current engine crisis by building their own 'power unit'.
Currently, the British team are struggling for the third consecutive year with works engine partner Honda.
However, reports emerged recently that, fresh from splitting with the Red Bull-Renault project, Formula 1 engine guru Mario Illien and his Ilmor company are now working with McLaren.
It triggered rumours that McLaren could emulate the success of their road car project and go it alone by building their own F1 engine as well.
Yet new McLaren executive Brown played down any comparison between the F1 team and their road car division.
"McLaren Automotive is another branch of the business," he is quoted as saying by Auto Bild.
"We are not an engine manufacturer - we are a racing team and a car maker. We don't know what we can do in 10 years, but this is not a relevant topic for us at the moment."
McLaren's former supremo Ron Dennis famously said that it is impossible to win in F1 with a customer engine, but one recent rumour was that the team is now contemplating dumping Honda and reverting to buying a 'power unit' from Mercedes.
Brown said: "It is possible to win races with a customer engine. But in order to dominate, which is of course our goal, we have to be a factory team.
"The decision to go with Honda was absolutely right."
McLaren remain pointless after the first two grands prix of 2017.