As I'm assembling my engine back (Skoda Estelle 120, 70s, RWD, rear mounted engine) I have the following issue: installed crankshaft, camshaft and distribution chain, torqued as manual recommends, it turns freely by hand (a little bit stiff). Then installed pistons: as soon as I put #1 I notice the engine won't spin freely but needs a wrench in the pulley nut...installed the rest of the pistons and now I need the wrench with a little pipe to assist it. Spinning it for a while seemed to soften it a bit. As I apply oil, and as it drips to the stand's pan, I see it gray like something is being rubbed.
Cylinders got sleeved, I'm using the same pistons the mill shop guys used for re-sleeving.
I have lubed and torqued the installed parts so far. Left the rings gaps as recommended, however found this issue: the oil ring, which came with the spring kind of inner ring doesn't seems to fit well in the piston grooves, because it seems that the spring ring is too thick. To make it fit, I stretched spring ring a lot until it got less thickness, then the oil ring with the spring ring could fit and the piston could get into the cylinders (it needed some blows with the back of a hammer, but when spinning for tests, I don't see the cylinders being scratched or marked)
So far it is not "seized" but won't spin without wrench + pipe.
Question: is this normal or at least acceptable at this stage? What it needs to soften out? More manual cranking? Or put the whole engine together and crank it via starter but without actually firing it?