I think it's this one. 3.0L Porsche 944S2 and 968

What's the largest 4-Cylinder Gas Engine ever put in a car?

Anything bigger?

Also, how does one get their engine looking so shiny and clean like this?

What's the largest 4-Cylinder Gas Engine ever put in a car?

What's the largest 4-Cylinder Gas Engine ever put in a car?