Connor
Hello Phantom,
There isn't a limit on the amount of engines you can have, however, if you have more than 10 engines when they are automatically replenished, you won't receive any more.
Engines are restocked to 10 (or 20 in a 2 car league), so you may receive less than 10 if you already have some spare. If you have more than 10/20, you won't receive any additional engines.
That said, if you purchase engines and have a lot of excess, you will not lose them at the automatic replenishment.
I hope this helps - if you require any further additional assistance, please feel free to ask.
Thank you
Guest