Here are two cars, all are operating radio control and the video was something to watch.

V-8 4 cam 4cycle 6.2 cu in, water cooled, dry sump oil,8000rpm,3.5 hp. it was real mellow sounding when he ran the engines.

4cyl 4 cyc 3.14 cu in mono block 3 hp 12,000rpm
this one did scream when ran