At the end of the compression stroke is when the piston is at or almost at top dead center. The intake valves and exhaust valves are closed. If you look at the first picture of my previous post, you will noticed that the cam profile (rounded pyramid) is about to compress the exhaust valve open(far end near the cam gear). If you look across from the exhaust cam, you will see that the intake valve has to travel 180* before it opens up again which would be the intake stroke.