Embeddable objects are not updated and orphaned references removed

@Entity
public class RaceDriver {
	@Id private Integer id;
	@Embedded private Car car;
	private String name;
}

@Embeddable
public class Car {
	@OneToOne(orphanRemoval = true, fetch = FetchType.LAZY)
	private Engine engine;
	@Column private String color;
}

@Entity
public class Engine {
	@Id private Integer id;
	private Integer horsePower;
}

    em.getTransaction().begin();

    final Engine engine = new Engine( 1, 275 );
    final Car car = new Car(1, engine, "red");
    final RaceDriver raceDriver = new RaceDriver(1, "Bob", car);
    em.persist( engine );
    em.persist( raceDriver );

    em.getTransaction().commit();

    em.clear();

    em.getTransaction().begin();

    final RaceDriver raceDriverFind = em.find( RaceDriver.class, 1);
    final Car carFind = raceDriverFind.getCar();

    //check, that at the moment the engine exists
    Assert.assertNotNull(carFind.getEngine());

    //update parent entity
    raceDriverFind.setName("Ted");
    //update the embeddable
    car.setColor("green");
    //orphan the engine object
    car.setEngine( null );

    em.getTransaction().commit();

    UPDATE RaceDriver  SET name = ?  WHERE id = ? 
[params=(String) Ted, (int) 1]