Greetings,

I have been working on a rebuild for my 2.0 engine with stock fuel injection. Installed the engine using some "they've been redone" heads. Bad idea. Almost immediately, on startup, after running several minutes, I had sounds like someone banging on a garbage can. Traced it down to a single cylinder, with zero compression due to a valve sticking problem. I have yet to pull the head, but one spring is depressed without the rocker assembly attached. Lesson learned by not trusting and verifying.

But to the point of my post: In the process of tracing down the issue, I ran a compression test. I was surprised to find, except for the cylinder with 0 compression, the compression on the other cylinders was 145, 120, 120. The engine was warm. The heads, with valves closed did seam to seal, as I tested them with lighter fluid. So, my question is, what should be expected on reused pistons with new cylinders and new rings that are not yet seated? In other words, does one not get to the 150 psi mark until rings have fully seated. Any advice would be much appreciated.

How long on the engine?
Some rings like Deves seat in as little as several blips of the throttle, Goetze are frickin hard as hell and can take 1000 miles to fully seat. At any rate you have to fix the head issue first.

If the head is fresh then the guide tolerance is too tight. Guides slightly crush when installed that's why they need to be reamed and honed after install.

Fix the head and any other issues, then you'll need a couple hours on the engine before you'll get an accurate comp test.
When rings haven't seated you can usually see blue smoke, I blip the throttle till it goes away.

Not long on the engine. Goetze is the brand.