chrankshaft bearing & bolt question

[scottsee]

this is a picture of the main bolts holding the cranshaf caps down, as well as the crankshaft bearings from my 4g63 91 lazer block.

Qestion #1: Red#3 shows obviously the crankshaft bearing, there are scuffs, and knicks as you can see from the picture, im currious if it is bad, all of my bearings look like this, including the rod bearings.

Question #2: if the bearings are not bad, would you recomend inlarging the holes in the bearings in Red#1? the oil is obvously obstructed by the bearings. ive checked all of them, and every bearing has a smaller oil hole then the ones on the block... is it suppose to be like that??

Question #3: Red#2 is one of the main bolts for the crankshaft. i was planing on buying ARP Main&Head bolts, but i realised the block had been rebuilt and these guys look damn new for a 13 year old car!! can any of you tell me if those are ARP or stock??

Thanks Guys!!

ps, i picked up the new Modified mag from wallmart while getting some cheap breakcleanr. they have a great writeup on Magnus Dogmission tranny. thats one Awsome Tranny!!

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[TSIfreek]

Those are stock main cap bolts and the oil hole in the bearing not being in line with the oil hole in the block is normal they all are like that. I talked to my machineist about this and there is no reson to inlarge the hole. The crank gets plenty of oil even though its partially blocked by the bearing. It is not a good idea to modify the bearings because you could damage them. If you do modify them make sure there is a good chamfer on them. Clevite bearings are real close and you should not have any problems. Just make sure you check them when you install them that oil can get though there.
The wear you see on the bearings is from dirt imbeaded into the surface and the scraches are also from debris in the oil not lack of oil. If you had a bearing that was not getting enough oil you would clearly see that, and the engine wouldnt last that long.
BTW use the correct socket on the bolts you can see you used a larger socket and rounded of the corners. It is metric 17 I think.

 

[half-cocked]

The marks in the bearings are caused by contamination, and byproducts of combustion like ash. I would reccomend against the use of ARP mains due to the fact that it makes the thrust car easier to misalign. Run a search for more info on this. The stockers will be fine for a street driven car. Most of the 6 bolt crankwalk cases I have read about have had to do with ARP's. Even one case where a guy used ARPs, crankwalked, replaced the bearing, CWed again, replaced it once more and swtiched to stock main bolts and as far as I know the car is still running.

 

[1fast97gsx]

I'm guessing he didn't have a line hone done?

 

[half-cocked]

That I dont know, but if I were to guess I would have said yes, he seems like he pays attention to detail.

 

[scottsee]

so the bearings do not reed replacing? thanks for the quick responcees! you all make my life so much easyer =)

as for the main's.... rodger that..

 

[half-cocked]

Replace the bearings, they really aren't somthing you should reuse unless you really have to.

 

[TSIfreek]

yea replace the bearings always. They are cheep.