Could the wrong oil do this?

[Glennster]

 My builder say I ran the wrong oil and that's why I toasted my rod bearings. Can that be true?  I removed the oil that came in the motor after 10 - 20 miles. Then after another 20 miles or so, I changed it because I had to remove the oil pan. Then,  I went to the 10w30 that was in it when it went south. That oil had maybe 30-40 max...
 This sounds like BS, but you guys know better than me.....

[Strawdawg]

I don't think so...

[quagmire]

That's a crock.  That bearing spun because the crush or clearance wasn't correct, or it was starved of oil.

[72cudamaan]

with all of the score lines running laterally on the bearing surface, it definitely had foreign material running through the engine.  Looks like a dirty assembly job to me.

[ireland383]

I second the crock notion. No way!

[4 speed fish]

I would take the bearings to other builders for input of what could of caused the failure.It seems like your builder is not going to take any of the blame.What was the warranty he gave you?

[duodec]

I don't recall from your previous posts; were you running flat tappets for the camshaft?  Courtesy of the enviro-gestapo at the EPA, current motor oils no longer have adequate high-pressure friction additives (Zinc something? ZDDP?  It was a big story here and on  other boards a couple of years ago) for proper break-in of flat tappet cam engines.  If your cam or lifters show a lot of bad wear or damage, that might have been the source of crap getting into the bearings.

Check your oil filter(s) too to make sure they didn't fail internally.  They probably couldn't be the source of the debris but they might have let it through, and there are some very poorly built filters out there in the wild.

[Chryco Psycho]

if the cam failed & ate the cam up the damaged brgs could be from that but the filter should still have caught most of it
as for the oil not protecting the brgs no way unless you used a cutting/ machining oil in the engine

[mopardave]

I would pull the other rod caps and check the clearances on the other bearings, they are stamped who there from and the size, run a pipe cleaner through the crank oil holes and see what you get. Oil would not create that kinda failure.

[Moparal]

10 w 30 did not kill your bearings on the crankshaft. Your engine was broke in also.

[1970-cuda340]

Kinda looks like someone put oversize bearings on a standard crank 

[Moparal]

i tried to reply glenn, but your pm box was full..... The reply was on every mopar performance crank I have ever bought.  They have to be worked on before installing them. Never had an out the box install crank yet

[72rtchallenger]

Kinda looks like someone put oversize bearings on a standard crank 

yea  or say the crank was turned 30 over and you used 20 over bearings,,the bearings should be stamped for size,,compare that to what the crank is,,was it standard or was it turned,,,you need to mic it,,compare that to bearing size,,no way the oil caused it unless you didn't have any in it,,your engine  re builder is full of bs,,maybe it was an honest mistake somewhere but that line of bs is just wrong,,the bearings will be stamped std for standard size or marked with numbers if it was turned to size,like.020 for example,,hold your ground on this,,everybody changes oil quickly on a rebuild,,just because you pulled the pan wouldn't make a difference unless you put metal shavings in it yourself,,,don't think you did that,,maybe happened quicker as you changed the oil,,but the problem was already there

[moper]

Yeah.. the OIL was wrong... Next time don't by the kind with PULP.   

It's hard to tell if the oil's protection was enough with all that debris in the oil system. What oil did you take out? What oil did you put in? What oil fiilters were used?

[femtnmax]

My builder say I ran the wrong oil and that's why I toasted my rod bearings.
 This sounds like BS, but you guys know better than me.....

That is pure BS.  You need a competent engine builder.  You probably live too far from me or I'd jump in and help.  I'm in the rocky mtns.
To start with, connecting rod big ends need checked for out of round, and may need resized.  Crank journals need diameters checked, maybe polished will fix them.  Entire engine block needs disassembled and cleaned spotless .... I guess cam is toast, and lifters probably too with all the metal in the oil... and go from there.