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Author Topic:   Premature Bearing wear??
Xtreme12x
Dirt Forum Champ
Total posts: 874
posted May 02, 2005 09:48 PM  
Had put the rotating assembly together last week, used STP as assembly lube on the main bearings, and ARP lube on the rod bearings. Been turning the motor over by hand once a day or so. I figured before I get the cam in there I would pull the mains to check the bearings, the front and rear mains were not as bad, but the middle 3 were very questionable. They each had grooves in them a coule thousands deep, you can't feel them with your finger, only your fingernail. The crank also has some small grooves in it now that only the fingernail can feel. Fresh Polish on crank, new Clevite 77 bearings, Scat 9000 Crank, Eagle Rods, Speed Pro Flat tops. The Rod bearings had none of this wear. What Gives? Is this a normal, or should i replace the Main bearings?

Note: I used Blue Shop Rags when building this motor and noticed that they leave some lint here and there, could that be the culprit? I used carb cleaner, then once that dried straight to STP on the mains with clean hands...

jpotter94
Dirt Forum Racer

Total posts: 94
posted May 03, 2005 03:07 AM  
did you polish the bearings before you installed them?what did you get for clearances on rod and mains.i always like to assemle with lubriplate or a quality assembly lube..could also be from some dirt during assembly..my rule of thumb is if they catch a nail,your askin for trouble..

ford5
Dirt Forum Champ
Total posts: 711
posted May 03, 2005 05:13 AM  
Sounds like it is from dirt or grit of some kind.......you can't be too clean when you do engine assembly, much success is from proper preperation and cleaning. It takes me 10 times as long to clean and prepare my parts than the actual assembly procedure. That said, the cleaning is the hardest part.

rico 08
Dirt Forum Champ
Total posts: 1139
posted May 03, 2005 06:15 AM  
I'd definitely use a good assembly lube,and not STP..also is the arp lube for bearings?the stuff i have is only for the bolt assembly.
one other thing..only turn the crank over as much as you have to

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted May 03, 2005 07:00 AM  
The arp lube is for bolts, bearings, everything. I used the ARP on the rod bearings and they look fine. I think I got a little dirt down in there some how, no clue how though. I'll pick up a new set of bearings for the mains today, pull the crank out and hand polish the crank with some light emery cloth..

I got .003 on the mains and .0025 on the rods.
I honestly think some of it is from the rags, they are very soft and have lots of lint in them. When I pulled the caps off the ones that were the worse had little pieces of something, very minute, in a couple small places... It is odd, the rear main only has a couple little scratches, front main isn't terrible, 2nd is not as good, third and fourth are questionable. I made sure to blow them off good before I installed them. Held up to the bearings that came out of it, the wear pattern looks the exact same... I just hope the crank is alright. Nothing really big, but A light polish should clean it up..

leapinlizard
Dirt Freak

Total posts: 402
posted May 03, 2005 09:54 AM  
Polishing Compound from the oil galleys. clean them with the proper brushes.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted May 03, 2005 12:05 PM  
Leapin has it, i'm pretty sure. I must not have gotten it blown out enough. Also going to be having the crank polished again and have the block cleaned/hot tanked and put a whole new set of bearings in for cheap insurance. Talking to a pretty good ole boy, he thinks that when I honed the block I didn't get all of the grit out of there. I'll probably take the block to the car wash and wash it real good with soap and water to get it good and clean, then tap the head bolt holes and start over. It's a good thing I caught it now, he said If I had fired her up, It wouldn't have ran more then 10 seconds without spinning a bearing. I've got a list of to-do's, he also said to blow the bearings off good once I get them in place in the block, and in the caps.

leapinlizard
Dirt Freak

Total posts: 402
posted May 03, 2005 02:30 PM  
Do all you metal work and save the cleaning for dead last. Chase the holes, grind, hone, cam bearings and all. Cleaning will come as last before assembly. Don't forgot every hole you can find has dirt in it.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted May 03, 2005 02:50 PM  
I went ahead and pulled the crank out, took it to the machine shop in town. A polish will clean it up. He wants the block also, he said more than likely after I honed it, I didn't get it clean enough. Even then, he said it would probably eat the bearings because some particles will hide behind the cam bearings. Going to have the block cleaned also. Going to be a long thursday night. Hopefully I can bust it back together and get it in the car Friday afternoon and fire it up, get it broke in.

racerman707
Dirt Freak

Total posts: 374
posted May 03, 2005 06:53 PM  
When you slide the bearings in the block and cap there is a little flashing that comes out. Make sure to watch for that and I read somewhere that transmision fluid will get the cylinder walls cleaner than anything else.

ford5
Dirt Forum Champ
Total posts: 711
posted May 04, 2005 05:57 AM  
Marvel Mystery OIL is a good cleaner too.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted May 06, 2005 07:14 PM  
Got it fixed...
Primed the motor tonight, If I have 60 LBS of Oil Pressure while priming the motor, what should I have at an Idle...

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