Piston ring install issues.

[DeCaff2007]

I'm FINALLY getting to building up my 94 350ci. I'm at the point where I have the piston rings installed around the pistons themselves and am trying to push the piston into the cylinder.

It's gets about this far... and JAMS solid. I can tap the piston back out from the other side easily enough, but this is as far as it will go from the top. It took several good hits with a dead blow hammer to even get that first ring to go that far. Something isn't right.

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Before anyone asks, yes I'm using a piston ring compressor. I took it off for the pic.

The cylinder wall is oiled up as is the piston and rings. I even measured the rings vs the grooves in the piston and there's PLENTY of room. Ring gap is well within spec... so WHY won't this install smoothly?

Funny part is, we just did this a while back for the Wife's Buick and aside from a huge mess, the pistons/rings slid right in.

Sorry if this seems rushed and grammatically incorrect but I'm in no mood to edit right now.

Suggestions?

 

[Spareparts]

Oversized pistons? Tapered bore?

 

[JOHNGAAA1]

Rings on upside down?

 

[Hipster]

some of the pistons in these tbi engines call for a less deep ring pack than others. I forget the specifics but something like an.160 deep ring pack verses standard depth 4 inch bore 350 .190 deep rings. Sure you have the right ring pack?

 

[DeCaff2007]

Pistons are the ones that came out of the block. Same ones go back in lol.

How would a tapered bore affect the ring install that close to the block deck?

Ring upside down? It's a rail for the bottom ring. Can't be but double the thickness of paper. How can that be upside down? I'll check, but that's confusing.

I appreciate the replies. Please keep them coming. Someone has to be right eventually.

 

[DeCaff2007]

some of the pistons in these engines call for a less deep ring pack than others forget the specifics but something like an.160 deep ring pack verses standard depth 4 inch bore 350 .190 deep rings. Sure you have the right ring pack?

Yes, I'm positive it's the correct ring pack. I measured specifically for that when ordering the rings. I even measured them again before install. They are correct.

 

[Hipster]

Yes, I'm positive it's the correct ring pack. I measured specifically for that when ordering the rings. I even measured them again before install. They are correct.

cool

 

[Hipster]

you have a pretty wide chamfer at the top of those bores, sure the rings aren't popping out a bit from the ring compressor, crank it tight band types can be bad for this

 

[Supercharged111]

To be clear, have you put the rings by themselves down in the bore to verify fitment and end gap?

 

[GoToGuy]

If the end gaps are correct as by stuffing them in cylinders to check.
What type of ring compressor are you using? May we see it? And a photo of it in use.
First idea is the ring compressor is not fully seating the rings in the lands, an edge is exposed, and clunk.
You have done piston install, right?
Plenty of engine oil on cylinder walls and piston and rings?
Without observing your install, and technique that's my thoughts.