In my quest to test the limits of the simulator and my PC, I've created this 130.2L abomination of an engine. Dubbed the R7950 Death Star, it's a singlerow radial engine with 51 cylinders! The most I've ever done on any engine. The engine script is over 2,000 lines long... It's so powerful, the dynamometer breaks. Which actually showed a torque limit of 10,000 Lbft.
This may in fact be a world record cylinder count for the vanilla Engine Simulator. The total record belongs to AngeTheGreat with his V69 engine, but he did need to modify the simulator to make that work. This engine is running on an unmodified install of ES v0.1.14a which really surprised me.