Shrapnel in Sump

concours said:

FIRST thought I had, but no way that made it down past the lifters.

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Great minds think alike and fools seldom differ

L.A.B. said:

Coincidentally, "about 0.023" thick" would be the thickness of an oil scraper rail and if worn could be 0.114" wide although the radius looks less than expected for it to be part of a scraper rail.

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Yes got to take my caliper measures as rough b/c the bit is distorted and measures varied depending on where caliper edges landed. At least is ruled out me primary suspect, that crank end shim at 0.003" thickness.

Lineslinger said:

Fast Eddies cartoon hits home...every time you go out that little piece of shrapnel is going with you.

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It's even more relevant if you ride a 961

Lineslinger said:

Fast Eddies cartoon hits home...every time you go out that little piece of shrapnel is going with you.

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Hence the username of a member here "Dances with Shrapnel". Might have to co-op that one someday.

Tornado said:

Yes the calipers were for thickness and radial width, the Metric ruler was just for a rough length to give things some scale. Thinking was most of folks here work in the "good Christian measures" (as Mr. Hemmings once exhorted to me over the phone ) and these might help better ID the flotsom.

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Born in 1957 I was taught both metric and imperial. Metric is 15/16ths easier to understand.

Tornado said:

Yes the calipers were for thickness and radial width, the Metric ruler was just for a rough length to give things some scale.

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Ok, as I think perhaps some of our forum members (me included) might have originally thought it was an inch scale as there's no reference.

A few more tries with calipers, attempting to get more consistent thickness, get me this:


Close up to show bend:




And finally the Thackery:



Sorry Cliffa.

Seems clearly NOT the Thackery based on the thickness...

MexicoMike said:

Seems clearly NOT the Thackery based on the thickness...

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Yes, I knew that the moment I picked up the old Thackery from my spares box...easily saw by even my poor eyesight it was much thicker. Mystery continues...

How about it has been in the sump for YEARS and was dropped in there at build or rebuild time.
The temptation to ride out the remaining season must be overwhelming. But the consequences of
further misadventure.....not appealing.

Onder said:

How about it has been in the sump for YEARS and was dropped in there at build or rebuild time.
The temptation to ride out the remaining season must be overwhelming. But the consequences of
further misadventure.....not appealing.

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I've only had that magnetic drain plug on the bike for about 6 or 8 months now. Can't recall if I've had it out for a previous oil change prior to this weeks removal. I usually just pull the larger plug to clean the sieve. So yes, quite possible this bit has been deep in the bowels for 45 yrs and only now found itself stuck to a magnet.

Guess one take home for those on these bikes, fitting the magnetic plugs can have benefits (unless you'd rather not know!).

Here is a long shot....it might be part of a keeper for rod nuts. I've seen these as a flat piece of sheet metal that goes under both rod nuts and an edge bent up over the nut to lock it. Perhaps some previous owner used such a thing. This is a long, long shot.

Just a thought... presumably engine is on first set of superblends? Did the factory actually fit them with steel as opposed to bronze cages?

seattle##gs said:

Here is a long shot....it might be part of a keeper for rod nuts. I've seen these as a flat piece of sheet metal that goes under both rod nuts and an edge bent up over the nut to lock it. Perhaps some previous owner used such a thing. This is a long, long shot.

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That would not be good news, for it suggests the nuts are backing off from optimum torque... but the oil pressure does seem to be very good

seattle##gs said:

Here is a long shot....it might be part of a keeper for rod nuts. I've seen these as a flat piece of sheet metal that goes under both rod nuts and an edge bent up over the nut to lock it. Perhaps some previous owner used such a thing. This is a long, long shot.

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The metal seems to be quite strong, perhaps hardened. I could not squash it flat using good sized hand pliers. Doubt I could bend it 90 degrees unless in a vice as for a locking tab of the kind found on other fittings.

Anyone got a Hemmings Engine Rebuild DVD I can buy or loan off ya?

That shoots down that theory.

I am repeating myself, but why not cut open the oil filter? If it is full of metal debris you don't have to wonder whether to pull down the motor. If it's clean it weighs towards this being some weird harmless event.

I'm feeling Deja-vu all over again.... didn't we have a similar mystery here before? Radius of curved piece too small for piston ring scraper, but mashed smaller?

The radius, thickness and width suggest this could be a piece of a crankshaft end play shim. However, I can't imagine what would cause that particular piece to break up once installed. You might check your end play as a small bit of evidence to put into your decision, along with the many other suggestions above.
I like the 'somebody dropped something in during an overhaul' theory, but what was its size and shape the day it fell in? Maybe the bottom end has already proven its ability to break this thing into bits? I once had a BSA lock up the rear wheel at 50 mph. Teardown showed a triangular piece broke off one of the piston skirts and wedged itself between a cam lobe and the casing. I was a newbie rider but had the presence of mind to pull in the clutch and get stopped safely. Wouldn't have been pretty in a curve though.
There are so many creative things to try. With the barrels removed could a thin magnet be stuck to the flywheel and sent on an expedition? Could a really strong person invert and shake the bottom end? The problem is, what if you collect another bit? What if you don't?
-The engine runs well and sounds fine. It seems like the risk of an expensive engine failure is low, and full teardown by a pro will not be cheap. Maybe nothing else will be found and it was already a broken piece of trash that got dropped in.
-Maybe whatever might be left in there could lock up your motor at a bad time which could be a life changer. This is a tough one. For sure I would be playing around with some sort of concoction of wire and magnet to try and sweep around the sump through the hole and I think I'd run the bike several times without riding and pull that plug out again to see if anything else is forthcoming. At some point it's either split the cases or accept the risk and ride it. Best of Luck with this one!!!