130TC crankshaft blued journals...
Posted: May 10th, 2019, 11:56 pm
Dismantled a 130TC many years ago due to rust and two nonexisting exhaust camshaft lobes. The engine had done approx 240.000km. I noticed a bit of wear on bearings...bronce coloured spots, and pretty sharp bluish shine journals on all journals. I have never seen this before, so I polished the crank out of curiosity to see what happened.....
The blue «layer» disappeared quickly - and I could find no scoring whatsoever. A bit surprised I measured the crank with micrometer, and found it to be round and within specified tolerances.
I still have this crank stashed away, but have not dared to use it, as I am not sure if it might have had some kind of damage done to the hardening or other...
I have two questions:
- What happened?
- Blue journals = scrap crank?
(Never took any pics, but ripped one from the web. I had bluing on all journals - just like the thrust area on the picture)
The blue «layer» disappeared quickly - and I could find no scoring whatsoever. A bit surprised I measured the crank with micrometer, and found it to be round and within specified tolerances.
I still have this crank stashed away, but have not dared to use it, as I am not sure if it might have had some kind of damage done to the hardening or other...
I have two questions:
- What happened?
- Blue journals = scrap crank?
(Never took any pics, but ripped one from the web. I had bluing on all journals - just like the thrust area on the picture)
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