Lost oil pressure at idle

[Ktbregal]

I know this is a vague question but could some the experts on here help me. I pull the motor apart and almost all of the rod bearings are shot and number 1 was spun. I haven't found a source yet. What are the common or not so common problems that would have been the source of the problem?

 

[bison]

Detonation, excessive clearance, too little clearance. Inadequate oil pressure.


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[Phoneguy]

Have the crank checked while it is out. My forged crank was bent .007 after a meltdown and wasnt caught before a rebuild, the journals showed no wear...engine started knocking after 40 miles and had to be rebuilt again.
My issue was a little different than yours but I would still have it checked for peace of mind.

Bryan

 

[Ktbregal]

Thanks guys. What's crazy is the engine only had a little time running. It had good oil pressure at cold start and idle. I did notice it started going lower at idle the last few times I ran it. I only took it out one time and got on it then it lost it at idle. It never made a noise and I kill it. It had a high volume pump on it which I didn't like.

 

[fastblackracing]

You can pretty much count on some or all of the rods were not true and round on the big end, I have seen several sets that were far from correct after they were reconditioned. Did the same shop that did all of the machine work also put the engine together?

 

[87GNSteve]

Did the oil galley plug fall out?

 

[Ktbregal]

No it has all screw in plugs

 

[TurboBuRick]

How's the oil passages in the front cover look?

 

[Ktbregal]

I don't know yet

 

[Ktbregal]

They looked open. The only thing I see is the larger hole had a little silicone covering the hole a little.

 

[Bob Davi]

Took one of our cars to track back in June 2014...made three nice runs, but after third run before shutting it off, we heard a slight "tick"...like a valve or maybe a lifter, but nothing heavy, like a rod or main. Started it again and ran at idle to listen,, oil pressure fine, but slight fluctiations...

got it home and started searching...Started it cold next morning, oil pressure shot right to 75#, ticking still there and then I moticed pressure starting to drop along with heavier knocking...long story short....must have had some detonation we didn't hear or see on scan tools, but it took out two rod bearings which lead to a rebuild.

This engine had steel shim head gaskets, so they weren't gonna give and it doesn't take much to go wrong at 24# boost with alky/93 Octane...somehow it went, BUT...BUT ..BUT, I have no compalints as this was an original factory bottom end with 123K miles and it was running 10:60's at 128...other bearings looked pretty good considering the miles and the power it was making.


Bob