Need Help no Compression

[calvin208]

ok i got a Datsun 720 pickup with the z20 motor. i got it from a family member and they blow the head gasket and so it sat without the head for a few years so i figured i would just rebuilt it but now it doesnt have only compression in any of the Cylinders can someone help

[turbojunker]

No compression as in zero? Or is it very low?

[flinterman2000]

The ring are probably seized. You need to completely scrap the engine to check from the bottom up.

[calvin208]

No compression as in zero

[calvin208]

im j/w if its got something to do with the timing or not and did the z20 come with the double or single timing chain

[PEZi]

i wanna say double.... never been inside of a z20 though

[calvin208]

thanks for the help.

[flinterman2000]

Yes its a double chain, but that wont help with compression unless the gear or sprocket has no teeth. And if not then too much compression when trying to turn the engine over on one or more cylinders as there is nothing to open the valves. No compression is either stuck rings or holed pistons.

[calvin208]

I don't know the piston looked fine and the rings are brand new and i heard the timing has to exact

[flinterman2000]

so it sat without the head for a few years

New dosen't matter over time. If you don't want to scrap the engine try adding some oil and gas mixed to the cylinders - not too much gas - to help with compression and try to start. But I really believe you will need to remove the piston rings, clean the grooves and reassemble.

[calvin208]

well i dont know so i pulled the motor and found a different one that we put in it. but it has a slight miss in but i thank its vacuum but not sure. but thanks you for the help anyways