what piston ring compressors do people use?

[steve briance]

Hello all,

I have a Laser piston ring compressor which i have used for 3 engines so far with no trouble but today using the same technique as before; I have found it awkward to use and now have one broken piston ring

do these things wear out?

In my mind the process was:

Clean clean clean everything.
Oil rings
Space the gaps at a 120 degree stagger
Oil piston skirt
Oil inside of piston ring compressor.
Fit compressor over rings and tighten so its ratchet mech cannot click any more.
Insert piston and tap into cylinder.
Tap around the edge of piston crown and feel when the top ring clicks past edge of bore.
Slide home and connect big end to crank.

The reality was somewhat different and the middle or top ring kept 'escaping' from inside the compressor and jamming against top of block. No way past that so out it came, reload compressor and try again. It was the 3rd piston that had broken ring so not as if it was even a hamfisted first attempt having done two successfully at that point.

The good news is that i have all of the broken bits, the bad news is I am quite a few pounds down and now waiting for some more Goetze rings to turn up from the Netherlands.

[DEREKCO]

I have used the same type for years and years building engines petrol and diesel never ever had a problem with that type of clamp

[steve briance]

neither have i until today!

Well, who knows what has happened. I have just been looking at the pliers type of compressor but am not convinced by them at all so i shall just have to be more careful when the new rings turn up.

[Error404]

I have used those coil types and they are a bit of a pain - you need to maintain solid pressure around the perimeter as you tap the piston down.
These days I machine a taper bored sleeve to knock the piston down. Admittedly not the most accessible tool for everyone but works every time.
If your machinist has been a bit too aggressive de-burring the block after boring / surfacing then the resulting chamfer doesn't help.