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Discussion Starter · #1 ·
What causes cracks like this in the deck surface of a block? Combo is a ProCharged LT1, 17 psi of boost, 10.25:1 static compression on E85. AFR 210 heads, stock block. .035" over. Tune is safe, absolutely no signs of detonation anywhere. Pistons, heads, valves, gaskets all look perfect. This crack is on the #3 cylinder, and on the opposite bank I have the same cracks going into #4 and #6. If Im doing something wrong, I'd like to know before I assemble it with another block.



Thanks!
 

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that's the only thing I can think of. either studs installed too tight or friction when torqueing the nuts down made the stud twist in the block causing the cracks. I don't think a tuning issue would cause this type of damage.
 

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If you torque a 400 Chevy to what ARP says I broke one just like that. When torqueing it up when can "feel" it break though. I would think no more than 65-70 w/stock block..
 

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Thought you were not supposed to bottom out the studs into the block. I always heard it cause stress points.
 

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Discussion Starter · #10 ·
I torqued them to 70 ft.lbs. Now that I think about it, I kinda do remember feeling at least one 'pop' while torqueing them. :mad:
 

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Discussion Starter · #11 · (Edited)
Thought you were not supposed to bottom out the studs into the block. I always heard it cause stress points.
They are not bottomed out. On a stock SBC they go into the water jacket. When I say they 'stopped', I mean when the shoulder of the stud didn't allow the stud to thread in any further.
 

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OK, not a chevy guys so thanks for that info, I will make note for sure. So with the SBC you have to seal them then?
 

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i run them in by hand after cleaning the studs and chase threads in block them i give the stud one full turn out i see on some studs ARP are putting a bullet on the end of there main studs just was working with a 454 main studs and they had them along with there new flange nuts. on a open deck were threads are not blind you want a sealler on the bolt or stud then if teflon base sealler you may want to back off TQ 10 lbs less
 

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did you use arp moly lube under your washer and nut? it looks like it was too tight in the block. You could have put them in finger tight but as you torqued the nuts down the stud could have turned instead of the nut on the washer. easy to do. Been there done that, busted one same as you did. live and learn.
 

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Discussion Starter · #15 ·
did you use arp moly lube under your washer and nut? it looks like it was too tight in the block. You could have put them in finger tight but as you torqued the nuts down the stud could have turned instead of the nut on the washer. easy to do. Been there done that, busted one same as you did. live and learn.
Yeah, I used ARP lube on the washer. I guess next time I will use more, lol. Thanks for your help guys, lots of good info.
 

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Discussion Starter · #18 ·
Bringing this back up. Anyone else experience this? It has happened again, exact same studs in a different block. Permatex sealer on the stud threads, turned out 1 turn from finger tight. 60 ft/lbs torque on the nuts. Head and deck were flat, Cometic MLS gaskets.
 
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