Can Helium Change How an Engine Sounds?

Garage 54 has brought us some pretty cool videos from building a self-propelled car engine to turning a toilet to a sub-woofer box. Now, in their latest clip, the mechanics try to use helium and sulfur hexafluoride on a car engine to see if it changes its sound.

If you are not familiar with this process, inhaling helium gives humans a very high-pitched voice while inhaling sulfur hexafluoride gives them a very low-pitched, almost evil, voice. The mechanics speculated that if these gases could alter human voices, they may just be able to alter an engine's sound.

We know what you might be thinking next. How do they insert the gases in the car engine? The mechanics explain that since these gases don't combust the engine might stall. This does not stop them from trying though.

They claim that if the engine does stall, they will proceed to feed the gases straight into the exhaust tract. Are we the only ones concerned that the whole car might blow? Clearly, this cannot be one of the dangers as the mechanics would not attempt the experiment if it was.

So, what does happen to the engine when the gases come into contact with it? Watch the video to find out..