The Lada Riva is basically a licenced copy of the Fiat 124 and although the engine is Lada's own, it was designed for them by Fiat's Aurelio Lampredi, who designed the SOHC and DOHC Fiat engines. He'd previously worked for Ferrari, designing the 'big' (3L and up) V12 series.
Lada modified the 124 design in a number of ways. The ride height was raised by moving the suspension mounting points down. Great for poorly metalled Russian roads, but no so good for handling. They also used thicker gauge metal for the bodyshells. They didn't have Steel mills that could produce the high strength allys that Fiat used and the cars were a good bit heavier as a result. Some changes were a good idea, the rather troublesome read disc brakes of the Fiat 124 were replaced with generously large alloy drums with cast in Iron liners.