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The Road to Drag Week 2016 / Re: Drag Week 2016 - Random Viewer Updates
« on: September 12, 2016, 04:07:28 PM »
8.949 sec @ 150 MPH!!!
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I just had a 2U crank turned 10/10 by a local shop, looks like they polished the rods but forgot to polish the mains. The mains had ridges enough to catch your fingernail on. I figured no big deal, brought it in to work one evening (a metal fab/machine shop) and chucked it up in the lathe. Bought some 400 grit paper and a shoelace and went to town on it, inspired by this video:
https://www.youtube.com/watch?v=j7DZxqPUQto
It took longer than I thought it would but the results were very good. Didn't loose any more than 0.0002" if that, and most only 0.0001" using 400 grit paper and PB Blaster. It's installed in an engine but not running yet. I think the journals look just as nice as any other normal machine shop finish.
-Jake
That's the vid I was thinking about, also. I have some cranks that have light surface rust on them that probably don't warrant sending out for machining. It seems to me that 400 grit might still be to rough. Not sure on that, hence the question. Could certainly progress to a higher number, but at what point are you just wasting your time?
My cam bearings failed as well, even though they were installed correctly. Never did figure out why, some suggested just a bad set of bearings.Wow John, that's interesting(scary). Did the engine do OK on the second set of bearings?
Should not have caused the problem.The cam journal surfaces look really good, clean and smooth - almost polished. Just like you'd expect to see out of a good running engine. Nothing else noteworthy about the break-in. All the connecting rod and main bearings look fine.
Not certain about King, but all others with the single exception of ACL use Durabond for cam bearings - - they are all the same inside of the box...