How to use a ring compressor

When installing a piston ring an conrods, can I check one piston at a time to see, if the con rod bearings are spinning freely? To make sure the con rods bearings and rings are not too tight or to loose???

Hello, Shareen yes you do have to check this. In the Coarse, we go into this in detail, with examples on how to measure both the ring clearances and the conrod bearings,

you will need some basic tools for building an engine to measure the clearances also which are also covered in the courses

Regards Ross

Might be a slight misunderstanding of the question - do you mean after doing the measuring, clearance settings, etc, as Ross said, if it's a good practice to turn the engine over a turn or two, each time a piston assembly is fitted, to check for potential problems?

I hope so, I do the same thing as even with the best care taken, an error may have slipped in and, if the crankshaft is suddenly noticeably harder to turn for one cylinder than any of the others, there could be an issue somewhere. Don't be confused by it being much easier to turn the crankshaft with the piston(s) at the top and bottom of the bores, and harder at the mid-point, as this is just due to the geometry of the engine.

A relatively common thing, especially for new builders, is getting the oil control ring expander (the middle bit that sits behind, and pushes against, the two thin rails/rings) ends overlapping, rather than butting up against each other. Not something I recall doing (but may have?) and it may show as an extra drag for that piston.