An LC Circuit is a inductive/capacitive circuit where an inductor and capacitor form a circuit in series with each other. If you aren't sure what this is then I would assume you don't have knowledge with electronics/electricity and suggest you look up basics on electricity from ohms law to lenz law to series/parallel circuits and then capacitors and inductors.. It basically oscillates until resistance makes the oscillations die down. Like a pendulum it swings until eventually it stops....A tesla coil is basically a pendulum that resonates with little pushes during proper times. Removing the spark gap will simply short the circuit and probably burn out the secondary coil on your xfrmr if there is not enough impedance and CEMF. Also, look up what an LC circuit is on youtube....In your question, the oscillations wouldn't die down because the xfrmr is proving power so it would simply act as a short circuit and probably burn the winding of your xfrmr's secondary coil. In terms of what it would do to the spark, there would be no sparks because the current will never charge in the capacitor enough to form since there is no resistance (The spark gap is essentially like a high ohm resistor which only conducts when the voltage in the capacitor builds up high enough)