No compression, cranks but no start

[MintFlavored]

So my brother's 1991 GSX Automatic lost power then died on the road. After getting it back to my house, I did the usual checks... it has spark, and fuel. The motor cranks normally, perhaps a bit fast, but it won't start.

I got my compression gauge out, and did a check. 0 on all 4 cylinders. Just to make sure I wasn't being a dumbass, I checked the compression on my motor, which came out to 145 or so on all 4. So I know how to use my gauge...

The weird thing is that the cam gears and timing belt are spinning normally, the cams are rotating freely, the valves are all moving up and down, and I don't hear any unusual noises.

Could the Headgasket have blown out enough to cause zero compression?

Could the valves be bent? What could have bent them and leave the timing belt and remainder of the valve train intact?

Any help will be greatly appreciated...

 

[TurkF26]

someone correct me if im wrong but with a blown HG i still think there should be some compression.

are you sure all the timing marks are still all set and that it didnt jump some teeth???

try a leak down test also and see where you get with that.

 

[huafist]

It's jumped timing and bent valves. Pull the head.

 

[luv2rallye]

Yes - a bent valve will cause 0 compression on that cyl. (as will a hole in the piston).