pics of my bearings for the 408
#1813850
04/28/15 01:32 PM
04/28/15 01:32 PM
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Joined: Jan 2007
Posts: 8,067 Mt Morris Michigan
mopar dave
OP
master
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OP
master
Joined: Jan 2007
Posts: 8,067
Mt Morris Michigan
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the bearings are set up L to R #1 main thru #5 and same on rods L to R. uppers are at top and lowers on bottom. they have about 40-50 passes and 1500-2000 miles i'm guessing. what do you think? did they get enough oil and especially #1 main and rod?
Last edited by mopar dave; 04/28/15 02:27 PM.
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Re: pics of my bearings for the 408
[Re: mopar dave]
#1813952
04/28/15 03:51 PM
04/28/15 03:51 PM
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Joined: Aug 2003
Posts: 43,725 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,725
Bend,OR USA
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The rod bearing look good to me I would check the actual run out on the # 2 and #4 crankshaft mains to see what is causing those two main bearings to look like they do I've seen more than one SB crankshaft have run out on the #2 main Let us know what you find out
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: pics of my bearings for the 408
[Re: mopar dave]
#1814440
04/29/15 08:53 AM
04/29/15 08:53 AM
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Joined: Feb 2005
Posts: 28,312 Cincinnati, Ohio
Challenger 1
Too Many Posts
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Too Many Posts
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
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the upper rod bearings look to be more worn in the center while the lowers appear to be more worn on the outside edges. i'll have to mic the crank when I get time. The upper rod bearings should be the only ones showing wear, the lowers are just along for the ride. Hows the rod bearings crush? I bet not good?
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Re: pics of my bearings for the 408
[Re: mopar dave]
#1814553
04/29/15 01:28 PM
04/29/15 01:28 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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[code][/code] the bearings are set up L to R #1 main thru #5 and same on rods L to R. uppers are at top and lowers on bottom. they have about 40-50 passes and 1500-2000 miles i'm guessing. what do you think? did they get enough oil and especially #1 main and rod? If my bearings looked like that after the amount of use you described above, I'd be concerned about the source of the problem. The rods look "so-so" at best, and a couple of those crank bearings just plain look bad, maybe like temporay oil starvation. Not sure I can add any more to what others have said. I, too, suspect the crank has issues, but would want to verify there are no obstructions in the oiling passages, etc.
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Re: pics of my bearings for the 408
[Re: mopar dave]
#1814598
04/29/15 03:04 PM
04/29/15 03:04 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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I don't understand that last comment. ANY positive displacement pump oils by rpm. The flow out of the pump is directly proportional to the pump speed, which is directly proportional to crankshaft speed. EVERY engine wet sump oil pump is a positive displacement pump. I believe all of the dry sump pumps are as well. It could be possible to use a centrifugal pump, but operating characteristics of a centrifugal pump don't match engine lubrication needs very well.
I do not understand why you would say that a Melling pump would be all done by 3000 rpm. Melling makes most of the oil pumps that are sold for the US market. There is nothing about the design of a Melling pump, or any engine oil pump of which I am aware, that would make that happen.
On the other hand, if the oil pickup tube is constricted, or if the oil gets all foamy above 3000 rpm, then something like what I think you are describing is possible, due to cavitation.
R.
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