Expander ring question.

[Bigfeet]

Okay here we go. Cruzin Image piston kit. Pistons and bore are fine. Top, second and oil control ring gaps are all fine. The expander ring seems to be way to big. When butted end to end it sticks out of the groove more than the thickness of the expander. Is it common to have to. trim it? Searched around and coundn't find anything about it. TIA

 

[WideAWAKE]

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[Bigfeet]

expander seems to be to long.

 

[Jim]

Doesn't seem like it, but when you put the two skinny rail rings on, it'll compress down. Just make sure you don't "overlap" the ends of the spreader... the ends have to "butt" against each other or the whole works will stick out.

This the type you have?

 

[Jim]

Make sure the gaps in the rail rings are opposite (180deg.) each other and the gap in the spreader is about halfway between the two.

 

[Bigfeet]

Jim ring gaps are opposite and fine. The spreader doesn't seem to fit in the bore without overlap.

 

[Jim]

Well as I said, it'll fit. You just have to keep working it in with the rail rings. If you overlap the ends, there's no way it will fit. Overlapping increases the thickness of the spreader and doesn't leave room in the ring groove for the rails. It'll never compress enough to fit in the cylinder.

 

[Bigfeet]

Not arguing the point at all. just never seen this before. The ring compressor can't squeeze it down enough to get it into the bore. It would have 2 notches of overlap to get it to go in and obviously I don't want that. With an old spacer everything goes together smoothly.

 

[Bigfeet]

I guess my other queston would be is its only job to keep the rail rings tight to the skirt or does it need to push them out to the cylinder wall?

 

[Jim]

I guess my other queston would be is its only job to keep the rail rings tight to the skirt or does it need to push them out to the cylinder wall?

A little of both. The rail rings.. or oil scrapers if you will, just lightly expand out to the wall.... but the way the spreader is designed, the rails also hold the spreader in place. Look at it close and you'll see a raised ridge top and bottom of the spreader. The rail butts against that.

 

[Jim]

With an old spacer everything goes together smoothly.

That's because the old one's been compressed down to fit. When it was installed initially, it was too big too. Might be worth pulling the oil rings off and starting over. Sounds like you might have the ends overlapped.

 

[Bigfeet]

We're on the same page. Just checked the circumference of the spacer vs the oil control ring its a good or 5mm larger than the ring. will it compress that far?

 

[Jim]

We're on the same page. Just checked the circumference of the spacer vs the oil control ring its a good or 5mm larger than the ring. will it compress that far?

Yes it will. It's made along the lines of an accordion. It'll compress down much further than 5mm

 

[Jim]

Try this.... install all 3 parts of the oil ring in the piston just like you'll use it. Lay the piston on your (clean) bench and roll it back and forth while squeezing the ring with your fingers. That should eventually work it down enough to fit in the cylinder.

 

[Bigfeet]

Been doing something similar with the compressor. I'll keep working it. It has a couple drops of blood on it now and every mechanic or carpenter knows that always helps. BTW its definitely not overlapped I can spot the split every time I take it out.

 

[Bigfeet]

After letting it sit overnight in the compressor it dropped in this morning.(Personally I think the blood made the difference) Gonna leave the second piston in the squeeze today.