Hello i bought my first tracker a few months ago with an engine problem. Its a 98 16v tracker and it only had 83000 miles on it. After failing to start it we took the engine out and rebuilt it and used a used cylinder head. Once we got it back together and dropped it into the tracker it started up fine and i drove it out of the garage and around the yard, but had only one key. So the next day i had one made and tried the key out but once i started it up, smoke rolled out of the exhaust manifold so i turned it back off but couldn't find any oil leaks except there was oil in the exhaust manifold and i haven't started it since and can't figure out what happened   can anyone help??

Did you try the old key to see if the smoke went away? 

Sounds very weird, check around the valve cover on the exhaust side to see if there is a spot where it didn't seal. It may be a small leak - it doesn't take much to make a lot of smoke. Either that, or you spilled some while refilling and it run down on the manifold.
I'd check it over really good with a trouble light, and then run it to burn it off while checking for any real leaks. Shut it off every few munutes and check you oil levels to see if it's dropping a bunch.

lol i wish it was that easy as to using the old key but i talked to some people and they said to check the plugs to see if there was oil on them, which there was a lil on the 3rd and 4th plug which i don't know if a ring would be bad or the head itself or what it could be, i wondered if the valve seals would cause it since it was a used head and i don't know how many miles was on the head. all i know is when i turned the car off and got underneth it i stuck 2 fingers in the manifold and got both fingers covered in oil 

Head gasket on upside down? It happens and cuts off oil to cam, and could cause oil flooding elsewhere?

dunno both sides looked the same and the cam was getting oil but not sure if it was enough

 Was the smoke coming OUT of the ports on the manifold or OFF the outside of it?

well the exhaust manifold was hooked up to the head which inside the bottom of the manifold was where the oil was, someone b4 me had cut the cat off so i didn't have all the exhaust hooked up, it was like either the oil was comin up from the cylinders or comin from somewhere in the head and draining down inside the manifold

 That's not a good sign... :'(

update,  took the cylinder head off and the pistons looked fine, poured oil down into the head and around the valve springs and noticed oil coming out around the bottom of the valves, possibly seals bad or may need a new valve job, now its time for a new head gasket and try try again

More than likely your valve seals are just shot...but for you to say that you actually stuck your fingers inside the manifold and it was covered in oil, the seals must be pratically desentigrated lol. I would say thats your problem though