Im swaping out a set of heads on my ls1, i cleanded out all the bolt holes took a stray and put to the bottom of the holes and blew in with an air gun, they were clean but when torqueing them down on two of them i heard a pop and it blew o hole thow the block. I dont know what to do.. can i run it this way? Do i need to pull the pan and see what happend? Can i even see what happend by pulling the pan?

 

I don't understand - do you now have a "hole" in the block. Junk in the head bolt hole usually causes a crack, not a hole.

 

Yes there is a hole thow the block at the bottom of the bolt hole. Ones a 1/4 of the size of the hole and ones the size of the hole bolt hole.

 

Can you confirm it's a hole through the block? I can't fathom that you put a hole through the block by torquing the bolt down. Pics?

 

Did you use two long bolts where there should have been short bolts? Are you SURE! there was no oil or water in the bottom of the holes? That can do it very easily.

 

Both holes are middle row ones second from front ones second from back on the other side so the bolts cant have been to long, I cant say i looked inside the hole cause i can get my head in there far enuf but but i blew in there quite a bit and nothing ever came out.

 

Yes stuck a wire in the hole and it gos clear throw. Motor is still in the truck so i cant do much as far a pics.

 

You always, always make sure visually check nothing is in the bolt hole.

 

A wire, the wire could just bunch up inside for all you know. Stick something solid, preferably longer than the head bolt and if it goes pass the bolt length w/ the head still on the block then it's safe to say there is a hole. Still I'd shine a light and take a pic.

 

Yeah lesson learned, but what do i do now? I dont think i can pull the pan without pulling the motor. Dont know about running it with a piece of the block in the motor,

 

i am not convinced that you have a problem. Others have reported that when using compressed air in the head bolt holes that air comes out in other locations on the block. In one case the head bolt hole intercepted another hole drilled in the rear of the block. So I am thinking that sometimes the factory drilled head bolt holes intrude into other passages with no consequence since the head bolt will be sealed by the head bolt.

 

I was doing the first 90 degrees then it poped, i thought the bolt snaped at first cause the bolt got loose again but i took it out and the bolt was fine. didnt have water or oil or anything on it. If i blow in the hole now i can hear the air blowing into the motor and hardly any air comes back out of the hole like the rest.

 

Took another look and i think i can pull the pan, the cross member can be unbolted. Now i need to know if this is going to get me anywere. Does it go to a different passage somewere or will i be able to see the hole?

 

If you really have a hole this is another reason to use paper towels rolled up tight and stuck down each hole to ensure there's no water left down there. Not saying that's what happened but always a good idea to blow it out and check with paper towels.

 

yeah this is a problem i shouldnt have, dont know what to do about this.

 

Bump.

 

bump again, shury someone out there can help me out with this. I hope im not the first one this has happend too..

 

I bumped this earlier because I still don't think you have a problem. I think that the pop you got was caused by threads that were not as clean as they should have been. I also think that the fact that the hole is opened-ended when there is no bolt in it is not a problem either unless that bolt hole penertrates a water jacket. I was hoping someone else could confirm or destroy my theory.

 

You could be right, I just dont think there was anything in the bolt hole, iv done many heads swap and never had anthing like this happen and im a clean freek and spent alot of time cleaning before installing. Im installing gm performance heads and i know they are milled but no one can seem to tell me how far but when i did the pvc check it came out to .030ish. so this means the bolts come down fethter and not helping things, theres some kind of glue on the bolts that i think wouldnt let air out also. I too have a hard time thinking it could pop the block.

 

If you have two holes in the block, there is no use to pull the pan. Pull the engine because it has to be replaced.