rainman69

I was putting together my engine and discovered a big problem. The rear lower head bolt (farthest to the rear, next to the #7 spark plug, one of the last to torque in the sequence) went in and felt like it seated. I started the torque sequence and tighened each bolt in order to 35 ft-lbs. Going around the second time at 50 ft-lbs, I noticed that the bolt just spun and spun. I backed the bolt out and checked the threads and it looked fine. I was able to put a small straw in the hole and when I pulled it out there were peices of metal on the straw that appear to be the threads from the bolt hole in the block.

So, the question is, how do I fix this? The car cannot be driven out of the garage. I also do not have the capability to pull the block from the car. There is a machine shop less than 2 miles down the road.


:smash:

Twin_Turbo

Heli coil it, you can buy complete kits w/ the coils, the tap and the install tool.

JoeC427

I feel your pain. It's happened to me.
Here is what you will need:
Right angle drill
New drill bit
Heli-Coil Inserts with the correct size.
Alignment fixture to keep the drill angle correct. (Your machine shop should have one. See if you can borrow it.
Don't worry it can be repaired, as long as you can get the drill on the hole.
Good luck :seeya

Crash Dummy

Gotta agree with Heli coil....

It stronger than the original threads too.

Rolling Thunder

:iagree: Helicoil is the way to go.

rainman69

Where does one get these things if the machine shop is closed for the holiday? Also, would a right-angle adapter work with a normal drill for this? I don't want to purchase a right angle drill yet...

rainman69

It's 7/16-14 correct? Requiring a tap for 7/16-14 and a drill bit of 29/64?

Barry's70LT1

I believe that a Heli Coil would do the job in a steel block.
However, there is a stronger fix, http://www.timesert.com
Timesert is the ONLY way to repair threads in an aluminum block.
I've used the Timesert product and they are great.
A Heli Coil won't hold in an aluminum block.

Crash Dummy

Napa... Autozone... any of them sell Heli-coil kits. I believe they even come with the correct bit and the installation tool for the heli-coil if you want it. If you tell any parts store where the stripped bolt is they can give(sell) you the kit. It's a piece of cake to do it. And amazing how well it works.

rainman69

Thanks, everyone, for the help so far. How do I ensure that I drill straight and how do I get a drill in there if I can't get a right angle drill?

JoeC427

If you can fit a small standard drill in the engine compartment, then I would use that. I mentioned the right angle because you would have more room to get the angle correct. The fixture I used was a custom made piece that the machine shop I use made. You know you still have to take the head off, so a regular drill may work. I believe your correct on the thread sizes. I have a BBC and I've forgotton some of the sbc sizes ect. I spent two hours tapeing and preparing the block ect. for surgery. It only to ten minutes to drill and replace with the heli-coil. :flag