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Old 06-27-2014, 05:31 AM   #1
RRR
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Default Rebuilt engine: Spun #4 rod bearing

I just rebuilt my engine with the following:

CP pistons
King bearings
Stock rods


It worked just fine during brake in. Changed oil + filter after 150 miles. Then at 700 miles out of nowhere I noticed low oil pressure when changing from 5th gear (engine braking downhill) to 6th. I stopped the car, looked at the oil temp gauge and figured it was due to the temp being a bit elevated. I started back up, started driving and then heard a horrific noise in the engine. It was the rod bearing spinning in the rod.


The low oil pressure was probably due to the bearing failure. Rod and crank is beyond saving, no other damage.




Im looking for advice on how this happened, before I rebuild my engine again. I rebuilt my engine because I cracked a ringland on one of the stock pistons. Bearings looked fine, but I figured Id swap them out, as I heard stock bearings are tight and cause oil starvation.

Anyways, the rods had almost perfect .002" clearances on them with a mix of King std and King stdX bearings. The crank was on the loose end of tolerances.


Braked in on mineral 5-30 oil. Fine oil pressure.




Any advice on what to check prior the rebuilding it? Im buying new crank, bearings, rods and oil cooler.
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Old 06-27-2014, 10:14 AM   #2
BeastianSTI
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Could send an oil sample out. Post a video of the sound?

Could have also had debris, metal shavings, dirt etc in your block which finally broke loose to wreck havok.

Edited. Ty

Last edited by BeastianSTI; 06-27-2014 at 12:54 PM.
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Old 06-27-2014, 10:29 AM   #3
meinct
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Quote:
Originally Posted by RRR View Post
...I rebuilt my engine because I cracked a ringland on one of the stock pistons...
.....
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Old 06-27-2014, 10:32 AM   #4
RRR
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I disassembled the engine yesterday to confirm, and found bearing #4 totally destroyed.
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Old 06-27-2014, 01:13 PM   #5
BeastianSTI
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Quote:
Originally Posted by RRR View Post
I disassembled the engine yesterday to confirm, and found bearing #4 totally destroyed.
Pictures do any justice ? Did the bearing spin in the rod, or were they just chewed into? I sent a picture of my rod bearings to a reputable shop to get their take on it (when mine was damaged after rebuild). Maybe you could do the same or post here.

Last edited by BeastianSTI; 06-27-2014 at 02:17 PM.
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Old 06-27-2014, 10:31 PM   #6
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Aren't you supposed to first start the engine, lets it get up to OP temp, then change oil?
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Old 06-27-2014, 11:15 PM   #7
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Quote:
Originally Posted by raggedoutsti View Post
Aren't you supposed to first start the engine, lets it get up to OP temp, then change oil?
Yeah that's the idea haha
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Old 06-28-2014, 01:55 AM   #8
raggedoutsti
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if you didnt change the oil from initial start up to the 150 miles i think that might be the issue.
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Old 06-28-2014, 01:58 AM   #9
meinct
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Not changing the oil in the first 150 miles will not spin a bearing. That is retarded
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Old 06-28-2014, 02:00 AM   #10
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Quote:
Originally Posted by RRR View Post
I just rebuilt my engine with the following:

CP pistons
King bearings
Stock rods


It worked just fine during brake in. Changed oil + filter after 150 miles. Then at 700 miles out of nowhere I noticed low oil pressure when changing from 5th gear (engine braking downhill) to 6th. I stopped the car, looked at the oil temp gauge and figured it was due to the temp being a bit elevated. I started back up, started driving and then heard a horrific noise in the engine. It was the rod bearing spinning in the rod.


The low oil pressure was probably due to the bearing failure. Rod and crank is beyond saving, no other damage.




Im looking for advice on how this happened, before I rebuild my engine again. I rebuilt my engine because I cracked a ringland on one of the stock pistons. Bearings looked fine, but I figured Id swap them out, as I heard stock bearings are tight and cause oil starvation.

Anyways, the rods had almost perfect .002" clearances on them with a mix of King std and King stdX bearings. The crank was on the loose end of tolerances.


Braked in on mineral 5-30 oil. Fine oil pressure.




Any advice on what to check prior the rebuilding it? Im buying new crank, bearings, rods and oil cooler.
Low oil pressure wasn't caused by the bearing failure....it's what caused the bearing failure...
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Old 06-28-2014, 02:01 AM   #11
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2 things you need to check why you had low oil pressure...

1. How low was your oil level.

2. Was your oil pick up tube stock and did it crack.
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Old 06-28-2014, 02:07 AM   #12
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Quote:
Originally Posted by murrdogg24 View Post
Low oil pressure wasn't caused by the bearing failure....it's what caused the bearing failure...
cancer causes smoking
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Old 06-28-2014, 02:48 AM   #13
RRR
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Oil level was good. Pickup was not cracked. I felt a minor power loss going uphill just before this happened. Could be IAT as it was a very hot day..will post pictures.
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Old 06-28-2014, 04:52 AM   #14
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Images as promised.








#4 rod



#3


#2



Main bearings:
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Old 06-28-2014, 01:03 PM   #15
BeastianSTI
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Quote:
Originally Posted by meinct View Post
Not changing the oil in the first 150 miles will not spin a bearing. That is retarded
By running the initial used to warm up to operating temperature more than for just that, you're taking an even greater risk of any sort of debris going through the system. That is why it's very important lol.
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Old 06-29-2014, 12:27 PM   #16
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Isn't 5-30 really thin for those kinds of clearances??? My builder said to use straight 30 for start up and the first 30 mins or so... Drain and fill with 20-50 vr1


Quote:
Originally Posted by RRR View Post
I just rebuilt my engine with the following: CP pistons King bearings Stock rods It worked just fine during brake in. Changed oil + filter after 150 miles. Then at 700 miles out of nowhere I noticed low oil pressure when changing from 5th gear (engine braking downhill) to 6th. I stopped the car, looked at the oil temp gauge and figured it was due to the temp being a bit elevated. I started back up, started driving and then heard a horrific noise in the engine. It was the rod bearing spinning in the rod. The low oil pressure was probably due to the bearing failure. Rod and crank is beyond saving, no other damage. Im looking for advice on how this happened, before I rebuild my engine again. I rebuilt my engine because I cracked a ringland on one of the stock pistons. Bearings looked fine, but I figured Id swap them out, as I heard stock bearings are tight and cause oil starvation. Anyways, the rods had almost perfect .002" clearances on them with a mix of King std and King stdX bearings. The crank was on the loose end of tolerances. Braked in on mineral 5-30 oil. Fine oil pressure. Any advice on what to check prior the rebuilding it? Im buying new crank, bearings, rods and oil cooler.
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Old 07-03-2014, 05:43 PM   #17
RRR
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Just measured my cylinder block main bearing housings, and #5 measured a major ovality of .0039".. Could there be a connection?
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Old 07-03-2014, 06:16 PM   #18
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The rear case locating dowel is bent if you are finding almost .004" OOR. Normally if either case dowel is bent, it will affect the nearest housing the most, then gradually they get better as you move away from the dowel. For instance, I would expect that if #5 had .004", #4 would have .003", # 3 have .002" etc. A bent dowel affects the entire block. There is not nearly as much pressure exerted on the front or rear main as the center 3. I've seen as much as .010" OOR on either #2 or #4 and the front and rear still measure fine. For this reason, I don't believe you have OOR from wear, it's an alignment problem.
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Old 07-03-2014, 06:17 PM   #19
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P.S. If this problem was present when you assembled the motor, the crank should have turned very hard.
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Old 07-03-2014, 06:57 PM   #20
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Close up pictures of oil pick up tube braze?
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Old 07-04-2014, 02:24 PM   #21
RRR
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Motion Machine, thanks for the input. Ill try disassembling, clean and reassemble it to see if that can help.

For info, #4 was completely round. 2 and 3 was about .0006" and #1 was .0015 OOR.
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Old 07-04-2014, 02:28 PM   #22
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Quote:
Originally Posted by OilyPablo View Post
Close up pictures of oil pick up tube braze?
I blocked one end of it, then blew into the pickup. There was no leak. So its def not the pickup on this one.. Almost wish it was, at least then I would know the reason why..
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Old 07-04-2014, 02:32 PM   #23
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Back to what others have mentioned, does it matter that you didnt drain the oil after the initial warm up? I did that once my hybrid was put together, the i drained after another 100 miles.

Maybe after u put everything together, tiny debris fragments chewed up the bearings. I mean 150 miles after putting things back together seems like a long time without draining the oil to me too.
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Old 07-04-2014, 02:33 PM   #24
RRR
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According to this, rod #4 is fed by main bearing #5. Interesting, but not conclusive..
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Old 07-04-2014, 04:37 PM   #25
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Quote:
Originally Posted by danger1138 View Post
Back to what others have mentioned, does it matter that you didnt drain the oil after the initial warm up? I did that once my hybrid was put together, the i drained after another 100 miles.

Maybe after u put everything together, tiny debris fragments chewed up the bearings. I mean 150 miles after putting things back together seems like a long time without draining the oil to me too.

There is a oil filter stopping that debris. So I can't really see how that would happen...
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