I removed #1 cylinder rod bearing cap to inspect the bearing surface. There are some soft metallic particles embedded in the surface. The crank looks OK. It looks like I'll need new bearings. I'll have a look at a main or two tomorrow. I wonder what that stuff is?
Regards, Neil Tucson, AZ
Neil,
Looked at your photo, needs more magnification, BUT, looks to me like "machining debris". Ie: the various micro-bits of iron, honing grit, etc, that might remain in the block, heads, oil lines, oil tanks, etc, etc.
I know YOU are meticulous, but I'm wondering if you paid anyone to "clean the block/crank for assembly"? It is VERY difficult to get all the associated "crap" out of a block,by just running it through a "jet washer". Blind spots and drilled passages can retain quite a bit of "swarf". And although most manufacturers of bits are well meaning, I check EVERYTHING. YMMV, and after all it's your wallet . . . . .
My method ( keep in mind my rampant paranoia . . . . .)
1/ Honing particles and grit are removed with mineral spirit or naphtha and brushes. ALL plugs removed from ALL oil passages, ALL brushed out. Cylinders brushed out also, especially the bottom edges where honing grit collects.
Deburr the bottoms of the cylinders, so they don't slice the part of the piston that protrudes below the cylinder at BDC. Get a brush kit, that's what they are for. Don't forget the threaded holes . . . . even new blocks can have
LOTS of debris . . . .
2/ Detergent degrease with HOT water. By hand or jet washer, doesn't matter. BUT, if the jet washer water is filthy, don't expect your block/heads/whatever, to be clean.
3/ HOT water/compressed air rinse. Hot water alone can work.
4/ WD40 or other water displacer spray to prevent flash rust.
5/ Compressed air dry.
6/ Most important of all: Thorough inspection! White paper towels or new lint free rags, or whatever, wetted with naphtha or "Brakleen", should be wiped on a random cylinder. Crankshaft oil passages can be checked with
"Brakleen" and a brush that fits the oil passage. Just like a "Marine Inspection" your block has to pass "the white glove test", AND, a flashlight inspection of the oil passages.
If it doesn't pass my inspection, SOMEBODY gets to "start over" . . . . . .
I'm certain others can offer their methods that work. As far as I am concerned though: "Cleanliness is more important than godliness." Over the years though, several of my cleaning guys have given me un-godlike nicknames . . . . . Use your imagination
JMHO, most machine shops do a poor job of cleaning parts for assembly. Most will not pass the "white glove test". My take is that your engine is going to make enough micro-particles during the bedding-in process. It doesn't need more to start off.
Fordboy