Some engines use a spark to ignite their fuel, and others rely on compression. What does all of that mean? And how do the two kinds of engines differ?

With the 5.7-liter LS engine test complete, we removed the LS and replaced it with our iron-headed 355ci small-block Chevy.

Increasing an engine’s compression ratio is a proven way of unlocking extra horsepower, but there’s a point of diminishing returns. The team at Garage 54, the Russian mechanics who built a V16 ...