Removing bearing material from crankshaft journals ?

[Smallfry]

Not sure which section I should post this, but anyway .........

I have a big old Ford six cylinder diesel engine (590E) that was fitted to a back up generator. It was allowed to run with too much sludge in the sump, which ended up blocking the oil pickup in the sump. I imagine what happened, is that a couple of journals were more or less starved of oil, so started to heat up and seize. As the fuel pump has a governor to maintain a particular RPM, the RPM started to drop, and so the governor increased fuelling to try and maintain that RPM, compounding the problem until the engine finally seized.

The engine has only done about 600 hours, and the cylinder bores are perfect, and the crank seems OK except for the melted bearing material melted onto a couple of the journals. The bearings are Vandervell lead copper items by the look of them. I dont want to spend a lot of money on having the crank reground, because I am too tight, dont really have a use for the engine ATM (stupidly gave away the generator bit a few years ago) AND, most importantly, my machine shop of choice is now within the London ULEZ.

How can I remove this material without causing any (further) damage ? Being it is most likely lead based, or possibly aluminium, I dont think anything acidic will touch it, and if it is lead, alkaline will not do anything either. I dont really want to try abrasives, except for final polishing, so thought about using a blowlamp to hopefully melt it a bit, and brush it off with a brass or wire brush, then polish it from there.

Is using a blowlamp likely to affect the crankshaft in any way ? It is forged steel, very hefty, and I am not thinking about making it anything like red hot !

 

[voipio]

A chiselling tool made of mild steel might do it, followed by wire wool. The bearing surfaces themselves should be surface hardened, so resistant to abrasion by mild steel.

 

[Pete.]

My mate's supercharged bike had some detonation and picked up some shell material on the journals. I cleaned them up with 600/800 grit emery and WD40 by hand and rebuilt the engione. It ran another 20k miles at least, with the supercharger on it.

 

[arther dailey]

diligent use of blow torch then clean as per suggested.

 

[GRW]

Where I'm.working now has a proper, bespoke crank grinding machine. It's old (& expensive) but a cracking piece of kit - (think lathe but with an extra moving, jointed arm opposite the operator behind the bed, with a driven grinding wheel that follows the elliptical arc of a B/E journal as the crankshaft is rotated).
It's not as expensive as I expected to get this kind of work done.
You can get 0.10 0.20 & 0.30 O/Size main & conrod bearing shells for lots of older engines as well (the firm supplies them with crank regrind jobs most of the time). I'm fairly confident that shells are available for the old Ford 4 & 6 pot engines.

 

[zzr1200]

Pictures would help, but I've used fine emery tape or cut strips of wet n dry to remove similar deposits with plenty of oil, but you really need a micrometer to check the journal diameter first.

If you can rotate the crank slowly in a lathe it helps

 

[Smallfry]

Where I'm.working now has a proper, bespoke crank grinding machine. It's old (& expensive) but a cracking piece of kit - (think lathe but with an extra moving, jointed arm opposite the operator behind the bed, with a driven grinding wheel that follows the elliptical arc of a B/E journal as the crankshaft is rotated).
It's not as expensive as I expected to get this kind of work done.
You can get 0.10 0.20 & 0.30 O/Size main & conrod bearing shells for lots of older engines as well (the firm supplies them with crank regrind jobs most of the time). I'm fairly confident that shells are available for the old Ford 4 & 6 pot engines.

Down this way, they want about £30 - 35 per journal. Bearings are not really a problem to get, but you have to buy two, four cylinder sets, and it adds up, which is what I am trying to avoid really, but might end up having to.

 

[Brad93]

Scrape the bearing material off with carbide by hand then polish journals with good quality emery tape.

 

[dobbslc]

If the melted bearings were aluminium then spirit of salts will dissolve it.

 

[8ob]

I would strip and inspect the engine, send the crank of for a polish. Its only a bit of time and the price of a gasket set for that piece of mind in knowing all is well.

Bob

 

[Master-of-none]

Lead, aluminium & zinc will dissolve in sodium hydroxide solution.

 

[dave h 2]

You might want to crack test the journals, be a shame to drop the crank under load.

 

[arther dailey]

I would strip and inspect the engine, send the crank of for a polish. Its only a bit of time and the price of a gasket set for that piece of mind in knowing all is well.

Bob

agree, I was presuming it was as if bearings gone particles will migrate through out.