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Old 08-08-2015, 04:52 PM
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3Phase 3Phase is offline
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Join Date: May 2008
Location: Simi Valley, CA
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T.C.,

It's possible Rich put a ring or two upside down. The marks (it's a letter on my new rings, not dots) on the Top and #2 rings are easy to see if you know to look for them, if you don't then the rings could be installed in all sorts of interesting combinations. That #2 bore and piston in his engine almost looks cleaner than mine is right now and it hasn't even been fired up yet! Naturally, the picture he took is blurry on the #2 bore but I didn't see any marks from a mis-mounted oil Expander ring. The cylinder wall finish and the rings/lands might have been mangled by fuel washing though, like I said, the picture is blurry on the #2 bore.


Greg,

Yep, I checked for taper, wear, and out-of-roundededyness.

I got this set of 2H7 jugs with pistons and rods from Andreas. There was barely any wear at all in the bores and the ring end gaps for the original rings were all really close to the minimum spec. even at the top and bottom -- unworn -- portion of the bores. I might have been able to re-use them but I found some pictures on the 'net that match up pretty well with what happened to the mobile mosquito-fogger, erm, engine on the Colorado Rally so I'm pretty sure that re-using used rings is what killed it.

The used rings weren't sharp enough to cut/break the new 'peaks' the hone made in the bores even with only ~18K on them so they just bent and smeared the metal into the 'valleys'. That caused the weird contact and blow-by patterns and along with the ring/piston/cylinder wall seal and lube failure, it hammered the you-know-what out of the piston rings, the ring groove lands and destroyed the pistons. I'd rather not do that again.

.
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