really odd

[panzershreck]

ok... while in the process of replacing all the belts & water pump on my M20 engine, i've really run into something totally unexpected... when putting the new timing belt on, i've discovered that the camshaft sprocket is 180 degress off, exactly 180 degrees... the sprocket has never been tampered with as far as i know, nor was it mis-aligned so tremendously in the process of taking off the original belt... so essentially, the engine has been running with a camshaft sprocket completely wrong... is this possible? did somebody just take of the sprocket off once and put it back on incorrectly? do you think i should risk it when i restart my engine with a possible mis-aligned camshaft?

[4-Door Flunky]

Hi, Schreck!
If you car ran fine before, put it back like that.
I think I know what's up, though. Everything except for dirt bikes, lawnmowers, and weed wackers has a 4-stroke motor.
That means that your engine has to spin two times for a cylinder to fire once.
There are two entities involved in this process. They are your camshaft and your crankshaft. You can tell what your camshaft is doing by looking at the position of the distributor. You can see what your crankshaft is up to by looking at the timing marks.
At the firing top dead center (TDC) for the number one cylinder, the exhaust and intake valves are both closed and the distributor rotor will be pointing at the pin to fire the number one cylinder.
If you rotate the crankshaft 360 degrees, you will be at TDC again, except this time the distributor rotor will be pointing 180 degrees away from the pin to fire the number one cylinder. That's the non-firing or exhaust TDC.
So, there are two kinds of top dead center. One when the cylinder fires, the other when it doesn't.
I suspect you have simply stopped your motor at the non-firing TDC instead of the firing TDC.
You can put it back together the way it was when you took it apart, or re-align the camshaft 180 degrees. It won't make a bit of difference.
Flunky
PS-Come over to the house and drink a few beers in the carport with me, and I can make this internal combustion philosophy clear to you.