Was attempting to degree my cams and the when turning the crank it started to bind. Didn't have a good feeling so I disassembled and found main bearing #1 was the cause.

Bearings were selected based on block/crank code, clearance was checked using pastigauge and checked out okay. Only piston #1 was installed to do the degreeing. Crank was spun by hand many times, well over 100 revolutions and spun very nice.

Anybody have any guesses what happened?

 

Is the crank surface straight? Was it well lubed (doesn't look like it in the pic)? Foreign material between the bearing or crank, or maybe under one of the bearings?

 

looks as if you spun it dry

 

Has several finger prints on the surface as well. The oils from your fingerprints are said to cause damage to the bearing surface. I am not saying this is the cause of the failure, just pointing out something you may not know. Perhaps it will help you in the future. That bearing looks to have had something pass through it.

 

looks dry, and does have oils from your skin on them, you may have gotten dirt in there as well that you could not see.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid96EK &raquo;</TD></TR><TR><TD CLASS="quote">Has several finger prints on the surface as well. The oils from your fingerprints are said to cause damage to the bearing surface. I am not saying this is the cause of the failure, just pointing out something you may not know. Perhaps it will help you in the future. That bearing looks to have had something pass through it.</TD></TR></TABLE>

so during assembly you shouldnt touch the bearing with your bare hands. Hmm, interesting I guess your supposedly to wear rubber gloves or something ?

 

What kind, I say, What kind, I say I say, what kind of crank?

 

Bearings were lubed with oil only since I was only degreeing. I was intending to tear everything down for final assembly and re-assembly with assembly lube. Bearings were wiped off to inspect and take photos.

I did pastigauge with these bearing so I did do some scraping to remove the old plastigauge with a credit card, surface of the bearings seemed to hold up okay.

The rod bearings seem to have a special coating on them, these do look like they are damaged easily. I plastigauged with a old set of bearings since I didn't want to touch these.

The damage on the bearing seems to be so concentrated in one small strip which worries me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Combustion Contraption &raquo;</TD></TR><TR><TD CLASS="quote">What kind, I say, What kind, I say I say, what kind of crank?</TD></TR></TABLE>

GSR crank from a different motor than the GSR block that I'm building with OEM bearings.

 

do you have a picture of that journal

 

the journal could have some taper but the wear I usually see with tapered cranks is closer to the edge of the bearing.

 

Looks like alittle piece of grit got caught up during the spin. You always have to be attentive before you torque everything down and make sure your polished surfaces are clean of any type of grit. Good thing you caught it before you turned the motor on. You might want to repolish the crank journal that had the spun bearing.

 

you spun the crank over by hand over 100 times with only engine oil for lubrication.....i would say the oil film dried up and caused the damage.

go to napa and get some permatex engine assembly lube. its red and sticky. it wont run off so quickly.

take the crank to a machine shop to have measured and polished.

 

Did you install the cap backwards or on the right journal ?
I.e. was the arrow on the main cap facing the oil pump as it is supposed to etc...?

If not, there is part of your problem...

 

The bearing looks very dry-not a good thing. The damage appears to have been caused by a foreign object.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by non-VTEC &raquo;</TD></TR><TR><TD CLASS="quote">you spun the crank over by hand over 100 times with only engine oil for lubrication.....i would say the oil film dried up and caused the damage.
go to napa and get some permatex engine assembly lube. its red and sticky. it wont run off so quickly.

take the crank to a machine shop to have measured and polished.
</TD></TR></TABLE>

I just caught that also, OP definately use some assembly lube even if it is just to take measurements.

 

yeah assembly lube &gt; motor oil for building a motor.
Not a big deal least you caught it before you did something stupid and possibly put your self in a bad spot. Where in your home did you assemble the motor? if in a garage make sure its clean and try and spray down the floor with water.

 

Thanks for all the responses. I think it's either dirt or dry bearings, I was only pastigauging and degreeing so figured oil will be sufficient... guess not.

No pics of the crank journal but it definitely isn't good to use as is. I have another GSR crank so will be using this one with a new set of bearings.

Motor is being assembled at work in the shop, it's a very clean place to assemble.