Quote Originally Posted by Jag_Warrior
As far as engines, I assume that if a team had the resources and wanted to build its own engines, it could. Just as Ferrari and Mercedes do. I have no idea if F1 has minimum supply limits, in case other teams would like to lease engines though. You used to see various steps or versions of engines being leased... customer engines vs. factory engines. I believe that practice has now been banned.
As far as I remember, there is a ruling that an engine manufacturer must be able to supply a certain number of teams (3 ??), but it isn't a must, that's why Cosworth supplies only one team - nobody else took them up on the offer. Same goes for Honda 2015. So far only one team will run Honda engines, but Honda could not refuse to sign up a second team on the grounds of wanting to be an exclusive partner to McLaren. They could however make their conditions (price) so unfavourable that no other team wants them - that's a different thing
I don't think - technically speaking - that any team builds his own engine. In the case of Merc, they are built by Mercedes AMG High Perfomance Powertrains, which is a completely different company within the Daimler AG empire. Without knowing the structure at Ferrari, I would suppose it is the same for them. Considering they have an own company for running older F1 cars (Corse Clienti), I would suppose the engine department is also separated from the core team in hierarchy.