Algodoo

I4 spawn engine hooked up to The Linkage's Dyno.
I flipped two of the pistons over in trying to stop high-density spawners from taking flight with a high output, which warranted a balancing shaft. Does instead mean that the thing quite violently tries to rotate, but when dropped into a vehicle it's not an issue at all

Starts off fixated so the engine can be soundly observed whilst running the dyno. With that fixate removed, it'll rock fine on the skid on normal ignition. The balancing shaft's phase can be adjusted by holding down either F or R to turn it, so you'll see the engine's vibration characteristic change whilst doing so.
It gets lively when running boost.

Controls in-scene

Gets ~340Nm from right at the low end, up to 13Hp at ~800rpm.