What is the biggest engine that fits in a car in Automation? It can build massive 10 liters engines, but the biggest that I could ever put in a car was a V8 6.2 naturally aspirated. With turbo this same engine is too big for any car, including the 3,05 m wheelbase sedan, that I guess it’s the biggest car of the game.
It all depends on what type of engine it is. For example you can fit a larger i4 engine into a car that won’t fit an i6 engine if the same displacement, because an i6 is much longer.
But to help with your question, I have been able to fit engines in excess of 7 litres into the long wheelbase sedan.
I’m giving away something here, but some of the frames (large 90s coupe, the Alfa type frame, the 80s coupe), all fit maximum dimension 10.9l v8 blocks. They can’t that with a turbo on top but I’ll leave you to find the balance…
Hope the devs make not just the cars huge but also motor bays on the 50 to 75 year range us cars with big motor bays. That’s half the reason why so many people put huge crate motors and larger versions of the original motor in them (53 olds with much larger 65 olds v8). Best example of this is the 55-63 GM cars NOT just Chevys. Its pretty common to put the largest v8 you can find in them. Like a 55 Chevy sporting the largest Chevy crate v8… the massive 572 v8.
Biggest I’ve shoved into a long wheelbase car was a 8.2L V8 bi-turbo. It was a tight, tight fit.
My next project car might be a 50s Nash Metro or my 56 Chevy. I want to put a Chevy 637 big block in it. High compression, cammed, 5 speed, dual 4 barrels. Just a simple old school pavement pounder getting around 600-750 hp. hehe
For the ringmaster challenge I fit a 10.6 pushrod v8 in the short wheelbase sports car. Tight but do able.
My biggest engine was an 11 liter v8.
The largest possible engine in game is 10587cc.
I think you meant 10857cc 
It’ll fit into the 80s coupe bay, and the large 90s coupe bay no problems.