Fire/flames that point downward? Need Help

Long story short, I want the prop rocket to have boosters pointing down. env_steam can point downwards but the common torch method (env_smokestack) does not.
You can POINT it down, but it goes horizontally (right to left as the world top-down shows). I've tried changing the pitch/yaw/roll in multiple set-ups but all to no avail.

Will it actually come down to writing a info_particle_system? The Valve SDK page suggests this is inadvisable for large flames so I would be cautious to approach it.

Thanks in advance.

Ok, for posterity steel uses an info_particle_system linked to the particle system flamethrower.
Just compiled a map with this entity and seems to work AOK. Obviously the smoke effects will be next but I figure a creative use of env_steam will suffice.

Kudos to the steel mapper for not re-inventing the wheel!