They don't make those engines either. Well thats a misnomer. They do, but its not all from scratch their own. Many in recent times used a very modified NissanSpeaking of McLaren.....why don't they make their own engines? They make hyper cars. Unless they don't make those engines either and i've been living a lie my whole life
A nice read on them
https://jalopnik.com/this-20-year-old-nissan-is-the-origin-of-all-of-mclaren-1793155467
Here is a video of the new Cosworth v12 engine for the Valkyrie. well worth a watch.