no compression

[MoToG]

ok so i rebuilt the bottom end of my sr20det left the head alone. put it back together arp head studs, aftermarket head gasket, the head looked to be perfect condition. so go to start it got spark and fuel so im like wtf, checked compression and it was 0, take the head off was worried that bent valves or something took them out all of them were straight. put it back on the block without the cams and by hand turning the motor i get 30 psi without the cams on so that means the bottom end is straight, so something is wrong with the cams, shims or lifters or something like that right??? its all stock head parts so idk im lost help please

[Justin35ll]

Was your mechanical timing off? Leaving the valves open a little bit and causing all the air to leave and having no compression

[FAST-DATSUN]

If you only get 30PSI with cams out you have a valve(s) problem or the botttom end was done wrong.... Have a leak down test done to find out if valves or rings are bad..............