I have a buddy putting headers on his LT1, which has aluminum heads on it. We're trying to figure out what to use, if anything, on the header bolts. He wanted to use blue 242 loctite on them, and I was thinking more along the line of anti-seize (to prevent the bolts from galling in the aluminum) and lock washers. I know a lot of guys on here are running aluminum heads with headers. Can anyone chime in and give us some tips on the best way to go about this? Thanks.

 

You want to use anti-seize on those bolts, since they are dissimilar metals. For keeping the bolts in place, I would strongly suggest getting bolts drilled for safety wire. Basically, the bolt heads have a hole drilled through them, side-to-side, and you tie the bolts together with mechanics wire so they can't spin. Works VERY well.

 

Yeah, the dissimilar metals issue is why I told him he should probably use anti-seize. I know when I used to work in a repair shop we always used a little on the spark plugs with aluminum heads, and I figured the same rule would apply with the exhaust bolts. Thanks for the re-assurance on that! If we can't manage to find bolts that are drilled for safety wire, I'll just tell him to pick up a good quality set of lockwashers to use.

 

I have run aluminum head for a while with different headers and never had any problems. Make sure the bolts are the right size, I believe I use a 1"bolt. If you think you will strip a thread then you can use a stud or Heli-coil it. Don't worry about troubles.

 

Lock washers don't work, and I'll tell you why.... lock washers have a cut in them, and are twisted out from itself. They rely on the springiness of the steel to grab onto the bolt head.

Now, heres the problem... header bolts get so hot, that the washers lose all their 'spring' and become just flat washers with a slot in them after a short time, and are no better than just regular washers.

If you can't find drilled bolts, get allen-head bolts (smaller head, easier to fit with headers) and the star-shaped lock washers. Those don't rely on being springy to hold the bolt, like the other kind of lock washers.

 

Yeah, I've used the allen head bolts in the past and they make it way easier getting to them and tightening them up. I forgot all about star type washers. That's a great suggestion!