I was putting my distributor together and forgot to put the cap beneath the rotor on... took it for a half mile spin to test the distributor and everything was fine. Came back to my spot and there it was, beside the old distributor, fml... Did i mess up anything from not installing that piece for that 1/2 mile drive/ reving it up.

 

it's part 6 on the picture

 

Called a leak cover.

Just take the cap and the rotor off and put it back on. In the meantime I wouldn't worry about it.

 

x2 you need to inspect to see if any damage was done anyway