Most late model vehicles have a plastic intake manifold. .22LR will stop the engine if the manifold is holed. I took some junk engine parts to a friends shooting spot. .308 will blow chunks out of a cast iron head or block. As will .223, but not such big chunks.
.357 Magnum and .44 magnum will bust up aluminum blocks and heads, marginal on cast iron. The plastic intake is vulnerable to even mouse guns, and most V-6 and V-8 engines have plastic intakes for the last 10 years.
For 35 years I have looked at engines I was working on, deciding just where to shoot to stop one. If I have my M1A even a Dodge diesel will stop on command.
Thanks for the info!