Doing heads on a ls1 and I didn't clean the bolt holes well enough. I blew out a small chunk in the block. There must have been enough coolant to hydrolock it. The engine is out so I got the pieces out. Has anyone had this happen, ran it, and had it blow up? Looking for opinions. Thanks

 

Pics??

 

Nope...

 

Hello new coffee table!!

 

Chance that it cracked into the water jacket... in that case, you have about 90lbs of scrap aluminum.

The head bolt holes in the block must be clean and dry or they can blow out with liquid in the bottom.

 

No it didn't crack the water jacket. I will post a picture tonite.

 

well now scared to put mine on. let me know if you find out what really caused it.

 

he mentioned it in the OP, he didn't clean the holes out. water and oil are incompressible, if you have either in the hole below the tip of the screw when you crank it down the hyrdraulic pressure builds up and something has to give.

if you clean your threads thoroughly and blow the hole out with compressed air then you have nothing to worry about.

 

This has happened to quite a few members. I don't understand why people don't check, re-check, and check again to ensure the threads are dry and clean. The results are just ugly, and a loss of so much money!

 

Agreed. I must have cleaned the head mounting threads in my block about a dozen times lol. I was still pulling stuff out of them, even after my initial cleaning on my tear down inspection and then after 2 separate washes at the machine shop.

I don't mean to be a dick but there's really no cutting corners when it comes to this stuff. It's unfortunate some folks find that out the hard way.

 

I spent 2days cleaning and re-cleaning my head bolt holes in my block. I used a impact air, a .357mm bore clearner brush, twisted paper towels and a flashlight to see the bottom of the holes before installing my ARP Head studs.

 

Does anyone remove the freeze plugs first before pulling the heads? If so, I presume antifreeze wouldn't get in the cylinders and bolt holes. I recently changed heads on a 5.3 and I too spent a lot of time cleaning out the bolt holes because the freeze plug on the passenger side was too hard to access.

 

just wanted to make sure that was the only cause. and theres nothing else i need to make sure i do. i already cleaned mine and stuck a video scope in them. looks good to go 5hp shop vac works pretty well to suck anything out. would it be worth running a tap threw them? or a old bolt and not trq it to make sure theres no water in the treads i can't see?

 

That's why i use studs!

 

I suggest the proper chaser by ARP. It cleans the threads well.

Get a flash light and look into each hole. Look and verify and BE SURE they are dry and clean. I like using long stock Q tips.

 

Does anybody know where I can find a thread chasing tap that's long enough to reach the threads? I got in the habit of using 'em on all head and main bolt holes on SBC/BBC builds but I have nothing that'll reach the threads on these blocks.

 

I just used a straw taped to a shop vac. Then notched both sides on one of my old head bolts. This was the most stressful part of the H/C for me...I spend A LOT of time cleaning them. Probably 20 minutes per hole.

 

Like was said, clean and clean some more. It's a pain in the hinny, but is critical. You can make a thread chaser by using an old stock head bolt. Grind flat spots on two sides of the threads and use it to chase the threads for gunk after you've gotten all the oil and coolant out of the holes.

 

just use a old head bolt to clean the threads.I use a air ratchet with a socket to screw in and out a old head bolt hole a couple of times.clean the bolt threads each time.don't bottom out the bolt in the head bolt hole.

 

For future reference, when you remove the water pump, use a shop vac to suck out as much coolant as possible.

If you get the coolant level down far enough it wont go in the head bolt holes when you pull the heads.

Good luck

Brad