Some of the big haul trucks in the mines have decent size engines in them. I used to work for Cummins and got into places that had some big engines. Most were Detroit Diesels back then.
I was overseas and saw an engine in a power plant that had hatches on the side so you could walk in and inspect it.
I worked on the starter engines for natural gas turbines in Michigan the were 500 hp v8 diesels. When we had to tear the diesels down they would start the turbine and with it running we would do our work. There was a 3" fan shaft that ran vertically by the rear head about a foot or so from the back wall. I was 160 pounds and the only mechanic that could fit back there. Fun stuff.
Right now here in Phoenix diesel is cheaper than gas.