<VV> Piston Damage from Guide Fragments?

N. Joseph Potts pottsf@msn.com
Sat, 14 Aug 2004 17:37:52 -0400

One of my pistons (#6) is a bit chewed up at the "bottom" (lowest point of
the periphery) from ingested metal fragments from the broken valve guide on
#4 described in my post earlier today. Some of the fragments seem kind of
embedded in both the carbon on the piston top and actually in the aluminum,
too. Naturally, this same effect is also to be seen on the head, but I'm not
using that anymore. I'd like to know what people think of my continuing on
with the pistons.
     First of all, I've pulled the jugs, and I find no evidence of scoring
of the cylinder walls. I've measured them for taper and out-of-round, and
they're well within spec.
     The pistons are another matter. One of them is pretty ragged. At no
point is the top "land" (above the top groove) near to being breached, but
it is pocked and right now, there are sharp spots that could become hot
spots (I noted no pinging before tearing the engine down), but I expect to
be able to shave these down with a Dremel tool.
     What do you think will happen if I do that, put it all back together,
and run it? Doing otherwise will at least involve replacing pistons, and
keeping my only Corvair off the road for a long time, so I'd like to avoid
that step if I can.
     Thanks for the benefit of your experience.

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C