Technical Small block Chevy head bolts won't come out

Trying to pull heads on a 305 Chevy. Couple of the bolts on each side won't break loose with electric impact wrench. Any ideas or tricks to break them loose?

 

Long breaker bar and 10' of pipe! No, have you tried some heat on them?

 

Ummm.... use a little elbow grease???... and a big old breaker bar.....

 

Get a better impact...

 

A breaker bar as was suggested, heat won't work because the heat won't reach the threads before you turn the head into a molten mess. I always try the least destructive things first, try the breaker bar without a pipe first then add the pipe. You could break the bolt then you have more trouble. If all else fails drill the head off the bolt and then remove head. Then deal with the bolt. Good Luck.

Pat

 

Smack the head with a hammer to shock the bolt. Then a breaker bar with a cheater.

 

Don't sbc head bolts enter the water jackets?

 

yup, they all go into water, and can get pretty nasty if the coolant hasn't been maintained.

 

Are you turning them the correct direction?

 

With the impact in the tighten mode, hit them a bit, then reverse. Repeat. All the while spraying some penetrating oil.

 

I've never seen any penetrating oil that will get under a torqued down bolt head to get to the threads on a bolt.
Harbor freight sells a 25 inch breaker bar for under 20 bucks that is handy as all hell 1/2 in. Drive 25 in. Breaker Bar (harborfreight.com)
Works great on tight lug bolts too.

 

^^Same here. Don't think I've ever seen any penetrant really get down in there in my life.

 

Why are you rebuilding a 305?

 

The heads are good for compression....

 

break off the bolts, then...with a pipe on a breaker bar. Make sure it's a really good 6 point socket, though

 

Get a tub and fill it with water and citric acid. Knock out all the freeze plugs and anything that will allow the mixture to get inside the water passages. You want to completely submerge it and shake it around a little to get trapped air out.
Then let it sit for a couple weeks. It will work on the rust from inside.
I don't recommend a cheater bar as you will probably either snap the bolts off or twist the threads out if any decent ones are left. Try your impact again and work the bolts back and forth. No movement..........back in the tub for another week and impact it again. If it still doesn't move, then its time for a bigger impact like the large "Earthquake" from HF. That thing is a "Hoss".

If all you want is the heads and not the block, then it doesn't matter if you twist the bolts off.

You can buy powdered citric acid on Amazon.


After a few weeks...........


Oh! and pressure wash the grease and oil off before you acid bathe it......

 

You have access to an air impact wrench. Works much better IMO