Anyone seen this happen before?

[xlfan]

It seems to be the lower oil ring guide ring that have caused this strange wear pattern on a -69 XL


xlfan

[attachment removed after 60 days by system]

[garyajaz]

a bit more than a wear pattern .
years ago with S&S stroker pistons I had lots of up and down wiggle on oil ring.
called the company.
they sent me another bottom rail and said pack that in to take up clearance.
I was not happy but those pistons lasted 10 years.
so is that ring pack loose in the lands?
and same gouge on both sides?
what kinda pistons??

[xlfan]

It's not the rings that are loose in the lands, it's the pistons that are loose in the bore and the big ends that are loose on the crank pin 

Piston to wall clearance of 0.030'' and serious wear on crank pin. I'm surprised that this engine ran at all    It looks like piston material has melted around piston pin, possibly caused by the serious piston clearance.

[garyajaz]

ah, ok
I saw that as a broken ring land above the pin.
I rode my 1974 stock (very hard) for 2 years prior to taking it down.
well, it sorta took itself down.  pistons were scored and some gouging.
but mostly the rod bearings were laying at bottom of case.
kinda a loose rod "bushing"  and it was running.  go ironheads..

is this its first time down?  how long have you ridden it??
I have a good stock crank or two about.

[Hillside Motorcycle]

That sure looks like a wrist pin that has walked into the cylinder wall.
The scared area on the piston is from the wrist pin clip.
Scott

[garyajaz]

scott, looks like the clip is in there.  is why I thinking broken land.
but yeah, that gouge looks like walking pin.

[saltcaveminer]

Sure looks like wrist pin walking.Salty 

[chopper]

I chased down a similar problem some years back. It kept recurring.Turned out to be rod bearings that were out of spec. Best we could figure out it let the pistons slap sideways and knocked the pins loose.
And it never made any excess noise.

[Hillside Motorcycle]

scott, looks like the clip is in there.  is why I thinking broken land.
but yeah, that gouge looks like walking pin.

I see the clip now.....had get my goggles on straight.........
Could it be this occured, and then was assembled that way?.......because if it was not, there would be evidence of that oil ring pack being buggered.
Scott