I bought a 94 accord with a blown head gasket, I got the head back from the head shop yesterday and I was putting everything back together. When I started tighten the head bolts in squence I realized that the longest head bolt just went down in the block. I took the head off and found that the threads in the block for that bolt are all gone.

I went to discount auto,pepboys,autozone,homedepot,lowes trying to find a thread repair kit and I can't find any.

Does anyone have any ideas on how to remedy this issue?

 

Man, you're pretty screwed. You can TRY a helicoil kit but helicoil's aren't designed to take that much torque. You'll need to get a tap in the size of the helicoil, then screw the helicoil (designed for the head bolt) and screw it down. Once you get to a certain point, the helicoil will break at a certain part, allowing you the thread the headbolt all the way down. It can hold SOME torque, but I'm sure not enough to hold the head down. Unless it's like my wife's old car of only 35 ftlbs, then you may be ok.

Hope this helps. Good luck on your project.

 

What about using a tap to rethread it to the next size larger and using a larger bolt?

 

The only way I know to make it as strong as it was before is to drill and tap it to the next larger size. But then you might have to drill the head for the larger bolt to go through. Then you would have to find a head bolt that size too. Then finally, with a larger bolt there may be clearance issues. Hope someone has an easier way.

 

i personally know someone that runs 5 helicoiled head bolt threads on a b20vtec. if done correctley can work, he has been driving his car for sometime now with no headgasket related problems...

 

5 of them WoW! What happened to all of them? That would be easier. Don't have to find a larger bolt, or drill through head either.

 

As mentioned earlier, Heli-coils work with great success if properly installed. It requires re-tapping the damaged bore, installing the insert and locking it in place. It's probably the only viable option since re-tapping for a larger bolt would require enlarging the corresponding hole thru the head as well.
Another option would be to install head studs in the block. Although I haven't researched that route yet, it would be a stronger option and would get around the tendency to strip out the aluminum block if you over-torque it.
Here's the Emhart Fasteners' Web site (helicoil homepage). Read up on it, but I would suggest having an automotive machine shop do it. You wouldn't want to trash your block, right?

http://www.emhart.com/products/helicoil.html

P

 

Helicoils require tapping a larger hole, and the quality of the joint depends heavily on the quality of the retapped hole. But if you're going to go through the trouble, in most cases, if you can use a larger bolt, just tap to the next size. You might want to get the help of a machine shop for this.

 

https://honda-tech.com/zerothread?id=1382274

check this thread. should be exactly what you are looking for.

 

thanks for all the replys, I was about to go to the junk yard and get a used block.but I'll try the thread inserts and see if thats works I just hope it can handle the torque.

 

If done properly, they are stronger than the original set-up. "Cuz now your bolt is engaging steel threads as opposed to aluminum, and the insert is inbedded into the aluminum and doesn't move (wear).

P