Bearing diagnosis
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Bearing diagnosis
Tore down my 385 sb with about 18K miles. Engine had good oil pressure 20-25 idle 50 at 2000rpm, 15-40 rotella.
Rods all looked about the same they had .002 pastiguage Mains were .003 .0025 .0025 .0025 .002 .003 F---R.
Rods all looked about the same they had .002 pastiguage Mains were .003 .0025 .0025 .0025 .002 .003 F---R.
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Jim
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Re: Bearing diagnosis
How sure are you as to the straightness of the crank?
The one bearing shell not showing much wear at all and progressively worse wear along the row of bearings makes me want to get the dial indicators out and check that crank very closely to prevent this happening again.
The one bearing shell not showing much wear at all and progressively worse wear along the row of bearings makes me want to get the dial indicators out and check that crank very closely to prevent this happening again.
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Re: Bearing diagnosis
Could be a combination of hour-glass shaped journals and contamenents/debris in the oil.
Lower viscosity oil would probably better choice with .002" rod bearing clearance and "reasonable" clearances on the mains.
Lower viscosity oil would probably better choice with .002" rod bearing clearance and "reasonable" clearances on the mains.
Bill
Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
Re: Bearing diagnosis
Mostly looks OK.
Center mains might have too much crush.
#1 a little twisted, loose in register?
Center mains might have too much crush.
#1 a little twisted, loose in register?
Re: Bearing diagnosis
Not sure on the crank being straight. Wasn't line honed, should have been & the caps don't fit real tight.
Don't have any plans of using the same block again, just don't want another build to look like that after a short time.
Next thing is the timing set that came out of it, should've lasted longer, yes?
Don't have any plans of using the same block again, just don't want another build to look like that after a short time.
Next thing is the timing set that came out of it, should've lasted longer, yes?
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Jim
Re: Bearing diagnosis
Whoa, that's not right.
Far as "looks" tri-metal bearings aren't known for winning beauty pageants.
You want them to look good get some aluminum bearings, but that's just hiding the truth. From what can be seen I'd say those bearings were working just fine considering.
Far as "looks" tri-metal bearings aren't known for winning beauty pageants.
You want them to look good get some aluminum bearings, but that's just hiding the truth. From what can be seen I'd say those bearings were working just fine considering.
Re: Bearing diagnosis
Surely the chain was super loose, to climb the teeth like that?
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Bearing diagnosis
Teeth on sprocket look like they have snapped off?
Rolon brand t/chain?
I have one here. Has Rolon on one side, other side says India....
Rolon brand t/chain?
I have one here. Has Rolon on one side, other side says India....
Re: Bearing diagnosis
Teeth on sprocket look like they have snapped off?
Rolon brand t/chain?
I have one here. Has Rolon on one side, other side says India....
Rolon brand t/chain?
I have one here. Has Rolon on one side, other side says India....
- BigBlockMopar
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Re: Bearing diagnosis
Street engine?
Engine cr?
20-25 oil pressure at how much idle rpm?
I'm no pro-builder but with a rather 'thick' oil like that I would've liked to see more pressure at idle, at least 30+ psi.
Engine cr?
20-25 oil pressure at how much idle rpm?
I'm no pro-builder but with a rather 'thick' oil like that I would've liked to see more pressure at idle, at least 30+ psi.
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Re: Bearing diagnosis
Take a gander here!
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You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: Bearing diagnosis
It had about 1/4 inch play, but it shouldn't have been that loose with the mileage it had.
Comp I think, chain is marked USA.
Jim
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Re: Bearing diagnosis
Barring other serious problems with this block I don't see why it cannot be align honed, caps tightened or pinned and re used again.
Timing chain must have been too slack with the gear set used. Look into better parts on your next build. If the chain still seems too slack on assembly then find out why.
Timing chain must have been too slack with the gear set used. Look into better parts on your next build. If the chain still seems too slack on assembly then find out why.
Re: Bearing diagnosis
Yes street engine 9.75 cr.bigblockmopar wrote: ↑Sun Dec 10, 2017 7:12 am Street engine?
Engine cr?
20-25 oil pressure at how much idle rpm?
I'm no pro-builder but with a rather 'thick' oil like that I would've liked to see more pressure at idle, at least 30+ psi.
Idle rpm about 750-800.
That oil press. was with a HV pump.
Timing chain was tight when I 1st put it together.
Jim