Honda Repair: Valve knocking after gastet and o-ring replacement, spark plug wires, honda accord

Question
1991 Honda Accord.  I had oil in my spark plugs, so I changed the top and bottom o-rings and valve gasket.  Everything seemed to line up correctly when putting everything all back together.  When I started the car up it was quiet at first, then it starting knocking real bad and won't stop.  What did I miss or what do I need to do to stop the noise?  Thanks.

Answer
Hmmm...There shouldn't be anything in there that would make it knock. Check your oil and make sure you are in the normal range. Make sure all spark plug wires are routed correctly.

I con't think of anything else that would cause any sort of noise.