Wiki says that acetylene is "intrinsically unstable", although it doesnt go into much detail apart from stating that it will spontaneously and explosively self-react when placed under high pressure.
Your note on the oil reminds me of an anecdote I'd like to share from my younger days. I used to be an avid computer hardware afficionado and used to overclock my equipment way past the design specs. To do this you had to up supply voltages and whatnot and also get rid of the heat generated. The colder the better; supercooled CPUs are able to overclock significantly. To that end I adopted, as I am wont to do, another hobby area of interest namely phase-change refrigeration. I successfully built my own system using a freezer compressor and a copper evaporator mangled from a block of copper using a hand-held swing drill and soldered-on cap. Crude, but it worked.
The serious overclockers in search of performance records employed what is known as a cascade - the outer cascade's evaporator would cool the condensor of an inner stage, which used a gas with a lower boiling point. Multi-stage cascades can be created this way, in fact it is how many pieces of high-tech laboratory equipment reach their design temperature. It is of course a highly specialized field but it doesnt stop garage tinkerers from attempting the same in the quest for a few extra MHz. And sadly, one of them did so with fatal results. Looking over the physical data for various gases, one overclocker selected oxygen as having the ideal boiling point for his next inner phase. He duly procured lab-grade oxygen and charged his cascade. A few moments after he switched it on, it violently exploded, killing both him and his helping mate, since he did not take into account the lubricant bath that the compressor internals sit in.
Oil + oxygen = BOMB!!!
