namell87

I am also building a similar 370 ci motor. Its at the machine shop and needs to be line honed/bored. Front bearing spun in block but not on crank.Being a junk yard motor i think it was out of a wreck that jarred the crank and messed up the bearing locator tabs allowing it to spin just my theory.

The question i have is when they line bore or hone the caps how does the machine shop relocate the skirt bolt holes in the cap. Are the stock caps now junk or is there a way a pulg is put in the cap and a new hole drilled and tapped? Or maybe weld the holes up then drill and tap? I am new to this style block and am not sure how this will be overcome. Taking the min. off the caps still make the bolts out of alignment with the holes in the caps correct.

Anyone with knowledge on how this issue is resolved please let me know how the process is done.

NVR_SPDS

iTrader: (39)

Line bore/hone doesnt mess with the height of the main cap. all it does is make the journal larger, to bring it back to round, or oversize for a damaged journal.

namell87

That is not what i have seen at machine shops any one out there correct me if i'm wrong but what i have seen is the caps are always milled a few thousands then torqued to spec then the hole is enlarged to the proper size. This isnt a problem on regular sbc as they don't have to bolt the caps horizonatally to the block, they only bolt vertically. On my lq4 there and two bolts that come in through the block skirting along the caps making it have 6 bolts in total holding the cap in place. If the caps are cut making them shorter those holes no longer will match up.

How does a machine shop compensate for that?

namell87

I guess this is either a topic thats not interesting or no one knows the real answer for this question. Does anyone know where you can get shorter timing chains to compensate for the change in location of the crankshaft being that it would be closer to the cam. Who makes a good double roller.

KCS

iTrader: (20)

Taking a couple thousandths of an inch off of the caps won't misalign the side bolts.

Abuckeye

I've seen the same. The 2 thousandths that r taken off should still let it line up. Put all six bolts in then tighten your bolts in the correct sequence. Don't leave the two sides out when you torque down the top of your caps

Abuckeye

Check everything with plastgauge on you caps

namell87

well good news block went together fine. used arp stud kit should make it hold together pretty good. thanks for all the posts.

bww3588

iTrader: (49)

An align hone will lower the cap in the block, an align bore will not but requires an oversized outside diameter bearing.

gpr

iTrader: (6)

I was in the similiar situation. I have an lq9 with a spun bearing. If they simply line bore the mains larger, coes anyone actually make an oversized bearing for this?

I looked around and found main bearings in .010" oversize, but i was assuming that was if you had to turn the crank journals down and needed a thicker bearing for that. Not the block being bored out larger.

The machine shop i talked to said the same thing. cut the caps down then re line bore the block.

KCS

iTrader: (20)

Why wouldn't you cut the caps like you would for an align hone?