Broken 2nd rings

[katman]

My brother-in-law took his 468 BBC apart for a rebuild. Last couple of runs, it was smoking and wasn't pulling very strong on the top end. This is a mid 11 sec car. On tear down, he found 5 of the second rings broken. We looked at both ends of the broken rings and there was shiny spots on both ends. This tells me they might have been broken for a while. The pistons, bores, spark plugs, and heads look fine. New pistons and rings (SRP, Perfect Circle) at start of season. All gaps and clearances were with in specs.
Any ideas?

[MadBill]

There's lots of guys with tons more experience here, but I'd say:
1. How about the faces at the break? Do they look like they've been broken a while too? If not, the rings might have butted, causing the shiny spots.
2. At least theoretically, a too-tight top gap could rob the second ring of gas pressure, allowing it to flutter and fail.
3. This second condition would be exacerbated by too much radial clearance.
4. How do the pistons look on the undersides? Black and carbon build up would suggest high temperatures which could precipitate above conditions.

[headman]

Sounds like the pistons were being "hammered" from preignition.
The second ring may be cast, explaining why it was subject to failure before anything else gave up.

[katman]

Faces at break are shiny also. Pistons look brand new except for a very light coating on the tops.

[SupStk]

This brings up an interesting question (at least for me), do you guys reuse pistons that had broken rings on them?

I've always been gun shy in that respect.

Any opinions appreciated.

[RRBD]

Every Piston I have pulled broken rings from, has been cracked, either in plain sight or by checking with Dye Penetrant. Russian Roulette, a least for me.....

Scott