Whats up with this bearing?

Talkwrench

Talkwrench

Well-known member
This is the center main bearing I just pulled out, was in the engine 3 years. What gives?
 

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I've seen many flathead bearings like that...too many! What the cause is I'll let the experts explain
 
I'm no expert. I'd say it is what it is. Probably run as is for another 3 years or more. Crank bearings are not typically line bored hence the wear on the leftside. It's a imperfect world we are just driving in it.
 
Looks like the bearing is delaminates from the base material .
You see some bearings have slight chunks come off sometime like this .
You might consider swapping in some new ones .
As long as the crank journals look good,,,,I wouldn’t worry too much .
Do a good visual inspection of the cap also,,,,,to be sure .
The wear pattern looks good,,,,,no serious gouges,,,,,you should be good .
All bearings are not created equal,,,,,,these things are made in a machine,,,and they are made fast,,,,,sometimes the bonding just isn’t perfect.
Also,,,,,well,,,,you get it .

Tommy
 
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That's called "Flaking" and was common with WWII bearings. This was also caused by excessive oil pressure. Had problems with the early floaters, back in the day.. Good reason for running a full flow oil filter.
 
Talkwrench said:
This is the center main bearing I just pulled out, was in the engine 3 years. What gives?
Click to expand...

That is a bimetal bearing, steel back and a tin/babbitt layer. They fatigue easily due to the thick layer of tin/babbitt.
Use a trimetal bearing like a Clevite 77 they are a hi performance bearing, steel back a layer of copper and a thin layer of tin/babbitt.
The thick layer of tin/babbitt is soft/compressible and the continued flexing fatigues the tin/babbitt layer and starts to crack and fall out. The trimetal bearing with the copper layer and thin tin/babbitt layer doesn't have this problem.

I had this same problem in race engines.

Bill
 
This is a typical example of bearing damage from "lugging" the engine. Of course their can be other causes, including a faulty fusion of the outer layer.
 
Good answers guys ,thanks.

This engine was the one that they lost the caps too and I had to get others so it was line bored. Lawrie ; Clearance should have been spot on the guy that did the crank said it was basically blueprinted [?] . The bearings were new . Yes I did the 90% oil filter setup.

John ;Lugging, interesting.. Most of my driving is too and from work however I drive it like I stole it most of the time .

Ron; Too much oil pressure, possible but does not go over 60 lbs. One of my worst problems is that I dont get the oil hot enough most days so the pressure does stay high.

Bill; good info the the types.

Well if theres anyone in Oz with a spare .030 bearing let me know
 
If it was mine, I'd replace the entire main bearing set - with a recently manufactured set. I'm running King Bearings on many of my recent engines - have not seen an issue like this to date. Check your clearances - as every bearing manufacturer is a bit different.

I've also had good luck with Clevite/Mahle P-Series bearings . . . just a little bit pricey.

Question: Whose bearings and are they NOS/vintage manufacturer or recent?
 
The bearing pictured is out of a 21 stud engine. Now it's hard enough to source genuine Ford bearings for these early engines, let alone aftermarket...The only aftermarket bearings I've seen for these motors were Repco brand. I don't think King make them....
There is an antique engine reconditioner here in NZ that can re-metal shells, often the only alternative when playing with real obscure makes.
Rob, just keep looking, you'll find a replacement. Good luck!
 
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