He earned 39 international caps for the Czechoslovakia national speedway team.
[2] Štancl reached the final of the Speedway World Championship on nine occasions between 1971 and 1984, finishing a career best 9th in 1982 in Los Angeles.
He won the Czechoslovakian National Championship twelve times, has appeared in the World Team Cup finals on seven occasions and in the Speedway World Pairs Championship finals seven times.
Štancl won the famed Golden Helmet of Pardubice in 1974, 1976, 1978, 1981 and 1982 and was also twice runner-up at the World Longtrack Championships in 1983 and 1985.
In the British leagues he rode for the Coventry Bees and Reading Racers.