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-   -   Slightly used bearings with new cranshaft? (https://vansairforce.net/community/showthread.php?t=170706)

jibby212 04-17-2019 06:27 PM

Slightly used bearings with new cranshaft?
 
My O360 with 3HSMO has turned out to be a total nightmare with corrosion throughout. My crankshaft failed due to pitting and having no luck on finding a decent used one, I found a new ECI. What do you engine guys think about reusing the bearings, they only have 3 hours on them, you can see that they just started showing wear marks. I hate to do it but this thing has me tapped out.

rocketbob 04-17-2019 07:30 PM

I feel your pain. What did the crank mic to? Can't be polished or ground over?

dreed 04-17-2019 07:36 PM

Sorry about your engine- that is rough.

How much are new bearings? I know you are tapped out, but if it were me, I think the extra cost/insurance of new vs. a potential tear down again to replace would push me over the edge.

I am sure there are some engine experts on here that'll chime in with better advice but I'd sleep better not worrying.

Good luck no matter which way you go.

jibby212 04-17-2019 07:41 PM

The crank had pitting in the middle main bearing journal fillet.

Mel 04-17-2019 08:07 PM

This is NOT a place to "cheap-out"!
 
New main bearings are cheap compared to possible alternative problems.

BillL 04-18-2019 06:49 AM

Just say NO, sorry.
 
I don't know what the cost of bearings are but would not reuse bearings operated with a scored/pitted/dirty crank.

Some bearings are solid aluminum, but they are intolerant of debris as it will not embed, simply score. PbSn overlays are there to allow embedding of tiny debris, if that is iron oxide, it will forever yield abrasive wear to the crank journals.

If the bearings were from an ultra clean engine for a few hours, then - - maybe - -but otherwise NO.

Cheap always costs more in the longer run. Add up all of these cheap decisions and the anchor just gets heavier.

PS: In 250 engine rebuilds, I never reused a bearing.

n82rb 04-18-2019 04:42 PM

General rule for any engine, never reuse main bearings.benn that way for all motor sports I've been involved with. Cars,boats,planes,motorcycles,snowmobiles they all get new bearings once they come apart

Bob rv4
N82rb

Mel 04-18-2019 05:21 PM

YEP.........
 
Quote:

Originally Posted by n82rb (Post 1340595)
General rule for any engine, never reuse main bearings. Been that way for all motor sports I've been involved with. Cars, boats, planes, motorcycles, snowmobiles. They all get new bearings once they come apart.
Bob rv4
N82rb

I've been an auto mechanic since 1960 and A&P since 1972 and that's always been the rule.

jibby212 04-18-2019 07:23 PM

Ok, I am adding new bearings to the list, thanks guys.

cgrossl 04-19-2019 05:56 AM

You might be able to sell your barely used bearings to someone in the airboat crowd. Just a thought.


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