Header Bolt ??

jeffnoel

Founding Member
Aug 31, 2002
1,638
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37
Clovis, CA
For those of you that have installed headers. What type of bolts are you using? I picked up some small head 12-point bolts and I can't get a socket on the bolts an the back side of the tubes.

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Right now I just have regular 6-point bolts. I can only get an open-end wrench on some of the bolts. One of these days I'm going to see if I can find socket-head bolts (ie allen-key) instead of hex-head bolts.
 
I used 6-point stainless steel and got a crow's foot on them to torque to spec. If you don't torque them enough you'll blow the header gasket in short order. I believe Wilson used a set of allen headed bolts on his car. I'm not sure where he got them though.

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That is what I used - Hooker headers. I used SS ARP studs with 6 point nuts. Anyhow I didn't have a problem once I bought the crows foot wrenches and used a short extension. I remember now why I used studs... the stock bolts that came with the headers were really hard to get started especially on the driver's side so I thought studs would be easier.

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The problem with a wrench is that you can't get any accurate torque numbers. Although with the thick flange that Hooker uses I'm doubtful you could under torque it. Also 12 point heads are really made for sockets... they are too easy to round off with a wrench. You probably already knew all of this... anyhow to answer your question, they don't make a 12 point crowsfoot that I'm aware of. :-(

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I've got the same issues with the Dynomaxes. I ended up using a reduced head header bolt that puts the head size down to 5/16" for easy access. I've seen the 12 point reduced heads offered as small as 1/4" but that may be a little too small. I prefer the 12 point over the 6 point as you actually have a little better bite on the bolt (think- like splines on an axle shaft) and you can crank it down tighter. I've rounded out way too many 6 pt bolts to fool with those again. I've also ran the allen head bolts on some other applications. They work great for the first couple times you tighten them and then they begin to round out. In a perfect world, I'd like to see a set of Torx socket header bolts. I think those would be the best you could possibly get. :nice:

But, yeah, the box wrench you're using is what it takes and use the 12pt socket where you can. Watch out fer dem knuckles!! :D
 
I used allen head bolts on my 5.0L H.O. I had to cut an allen head wrench 1/2 way through the curve and use an open-end wrench on it 1/4 turn at a time to get some of them. I also whanged the hell out of a couple of the headers, laying my 1/2" drive socket wrench against the header and hitting it with a hammer until the end of the wrench was over the hole. The bolts slipped right in after that. PITA.

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You can see, in the leftmost header, a slight crease. My handiwork as explained above. Cheap and nasty but it worked.
 
You cn put more torque on a 12 point external wrench head than an internal wrenchung socket head fastener.

Could try one of these:

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They go by starter wrench, V-wrench, U-wrench, Snap-On calls them half moon wrenches.

Would probably be esier, and cheaper, to get an (old) 12 point box wrench, heat and bend it so it works in this application.
 

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You may need to thin wall a wrenches box end.

In the last couple of decades I've noticed the walls of Craftsman level tools
getting thicker.
Seems the metal used is of lower quality so they have to use more of it.


You may need to not only thin the wall but also to reduce the boxes
thickness. I've had some box ends with a bevel inside the box that makes the
wrench pop off thin fasteners. Here it would just be getting in the way.


I know , hacking on tools goes against the grain. First time Dad torched I
wrench I thought he was nuts, damned thing would be useless for anythig
else. His response was, do I want that bolt tight? and sometimes you just
gotta do it.


Another thing that may help is to grind some height off the bolt head. Problem
with this is it could make it a real SOB to keep the wrench on.

If your go the 6 point route I suggest getting a close tolerance shim washer.
This will help in keeping the bolt head points from digging into the base metal.

Any way you do this, high temp Never-Seize the hell out of this.
 
It is impossible to get a box end wrench on that bolt with the Hooker headers on my II. You would have to crush the tube or cut it out to make it work. Anyhow I still recommend a six-point bolt with crowsfoot. Even then you will get very little travel on the torque wrench due to the limited clearance around the booster and firewall.

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OK, tried allens, no go as the heads to tall. Then tried some standard head 6-pt grade 8 bolts, no workie as the head diameter was to big. So I found some reduced head grade 8 6-pt header bolts that take a 5/16 wrench on eBay hope to have them by the weekend. Fingers are crossed but these should work.
 
I use regular 6 point header bolts and open end wrench to tighten the awkward ones.
Side note; If you use stainless bolts, I suggest not using the supplied polished stainless washers that come with them. On my Bronco, the damn things kept coming loose, because the polished SS surfaces were too slippery.

P.S. I've never seen a white engine before. That looks pretty cool.
 
Socket head bolts work good with a Ball ended Allen drive on a ratchet and/or extension. I've never used a torque wrench for header bolts (pitb). I guess my arm is calibrated as I've never had a header leak.