These Fearless Guys in Racing Cars(1976)

Original title: Эти бесстрашные ребята на гоночных автомобилях

Four boys and young Aziza live with the dream of building a racing car. They had to work for a whole year. And when, during the first tests, the car caught fire, the kids found the courage to acknowledge their mistakes, listen to the advice of adults, and start all over again...