Just curious - crankshaft oil passage question

Just curious - do the oil holes on the crankshaft ever clog up? Just replaced my bearings and mine were clean as a whistle - just a thin film of oil.

Anyone ever seen them clogged?

Only ever seen the crankshaft clogged on BSA twin engines.

Lousy design has the feed for the far side bigend going through the crank in such a way that it clogs up with muck over the years by centrifugal action.

All car cranks i have seen are diagonally drilled to bigends and straight out, so flush themselves clean with the pressure behind .

No funny little cavities to catch muck.

All car cranks including the MGB Pooch? It'd be great to know clogs are prevented by design.

If they clogged, it wouldn't be for long. You'd lose a bearing very quickly with insuffucient/non-existent oiling. Basil

Basil's comment does not mean it is not a good idea to brush/clean the crank galleys when rebuilding the engine (after turning/polishing the crank).

Mac, have you ever seen one just clog through normal use?

Found this in the library -

"There are diagonal holes drilled in the crankshaft from the main bearing journals to the rod bearing journals, and oil flows here to get to the rod bearings."

Combine it with what Pooch said and it sounds like it won't clog during normal use...............

the reason for cleaning has nothing to do with clogs. everything to do with residue

there is so much pressure coming out of the stock pump that thee is no way the crank would clog while in use.

Now if you threw it in a half barrel of water and old oil and left it there for 5 years, you might find the hole clogged with gunk and rust.

But not while in an engine that is being used and maintained at all.

That's what I was thinking - thanks!

What Basil said, it wouldn't last long. I torn down many, many engines, and never saw a galley in the cranksahft clogged, but I saw the main two oil galleys in the block almost clogged, filled with black oil sludge, about the consitentcy of toothpaste, I even posted picture here one time of this. During a rebuild, after one or more caustic washes to the block the last cleaning operation for me is a hot water wash, I use a chemical like purple power when doing this, I have engine cleaning brush set, which has a variety of sizes of small brushes that will get into all the orfices of the oil system, then a round toliet brush I use to scrub the bores and main saddle with. The neat thing about the hot water wash is you cansquirt water into orfices and see where the water exits, while this is cleaning those orfices, it also helps to educate you as to the flow of the oil within a block. Before I had mu own shop and raceed out of my backyard garage, I use to hook a hose up to the washing machine hot water connection. Yoy should never just trust the machine shop's caustic washing as the final washer, these spray cabinets are great, many have as many as 30 jets in them, however nothing is better than you with a hot water hose in your hand directing the water directly into all the otrfices. To be honest with you, that is something I always judge engine builders by, if they do a final hot water wash then they are being very through.