valve timing or the valves may be over adjusted and not closing.
Did you screw with the timing belt? If so, you put it on wrong. If not, the timing belt broke.
I am guessing your valve timing was off and you have a bunch of bent valves.
So I did the head gasket on my Saturn I have a 98 sl1 sohc 1.9 liter and I had it put all together and it started but it was ticking so I stoped it looked around and then started it again and looked while it was on then it just died. It made a weird sound. And it wouldn't start so the next day we did the timing on it and now it won't start and it has no compression in any cylinders and I can't find any info online. Please help. Thanks