Re: Spun Rod Bearing
[Re: 416challenger]
#1561836
01/11/14 04:03 PM
01/11/14 04:03 PM
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Joined: Aug 2003
Posts: 43,292 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,292
Bend,OR USA
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Pull the rest f the rod bearings and look hard at them for debris and to see if they have lost the bearing crush, if they are still snug and don't fall out of the rod caps and rods If they fall out they have lost the bearing crush, probally from detonation or pinging Detonation, debris and inadequate(SP?, to little) clearances are the biggest reason for rod bearings spinning, your motor live quite awhile so I would rule out the clearances being the issue IHTHs Let us know what you find
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Spun Rod Bearing
[Re: 416challenger]
#1561838
01/11/14 05:53 PM
01/11/14 05:53 PM
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Joined: Jan 2003
Posts: 5,486 SoCal
Brian Hafliger
master
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master
Joined: Jan 2003
Posts: 5,486
SoCal
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Quote:
What would be the cause of a spun rod bearing?
The motor is a 418 small block that has been together since the beginning of 2008. Probably has well over 1500 passes and 1000 miles on the street. The bearing were inspected and look good around January 2012 and they looked good. I run a 7 quart Milodon pan with full groove main bearing and a high volume oil pump.
Last Saturday on my second pass the car felt slow and was slow to pull to 6500 rpm. I went through the traps and lifted and heard a bottom end noise. I pulled the motor apart Sunday and I had spun the #4 rod bearing and pushed it out towards the crank. When it lost the bearing it hammered the rod and bent the rod cap. All the main bearings looked fine.
Why after all of this time did it spin a bearing?
Did you change anything, like tuning, fuel type, old fuel? Over reved? Same oil always used?
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Re: Spun Rod Bearing
[Re: mark_gates]
#1561844
01/12/14 09:18 PM
01/12/14 09:18 PM
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Joined: Dec 2006
Posts: 3,396 Pa
Hot 340
master
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master
Joined: Dec 2006
Posts: 3,396
Pa
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Quote:
I think if I'd had it apart enough to inspect the bearings, I would've thrown in a new set, just for insurance. Even if it's just pulling the pan, it's still doable and cheap. 1500 runs is plenty; sounds like they pretty much are timed out. I'm glad you didn't throw the rod.
with Mark.
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