i tried messing around with
this.onUpdate();
and...
public void onUpdate(World world, double x, double y, double z, double velX, double velY, double velZ) {
world.spawnParticle("portal", x + 1, y, z + 1, 1.0D, 1.0D, 1.0D);
also...
public void randomDisplayTick(World world, int x, int y, int z, Random random);
if (random.nextInt(10) == 0)
{
world.spawnParticle("portal", (double)((float)x + random.nextFloat()), (double)((float)y + 1.1F), (double)((float)z + random.nextFloat()), 0.0D, 0.0D, 0.0D);
}