Some people are not happy using a factory engine. Instead they want to build something unique. Take for example this Peugeot 103 moped powered by a custom V8 engine. The builder took eight single-cylinder engines and combined them into one V8. The website is in French so I wasn’t able to get a lot of information. Still the photos and videos speak for themselves.
Source: Diabolique103 via Tomahawk Tuning via TurboBricks