Question for the Experts!
Thread Starter
Instructor
Joined: Aug 2002
Posts: 118
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From: Monongahela PA
Question for the Experts!
When my head gasket blew on my 1990 L98, I had a real problem with those damn torx head bolts. I wound up chiseling most of them to get them to turn after breaking four torx head sockets. I'm considering replacing the torx with allen head bolts when reinstalling. Is this a good idea or should I stick with the torx?
I know several members have done this job more than once and would like to hear some opinions from the Experts.
I know several members have done this job more than once and would like to hear some opinions from the Experts.
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: Question for the Experts! (qwerty111)
so far everyone is responding about head bolts that hold the head down to the block. I think I read the post as referring to the torxhead bolts that hold the intake together and down onto the heads. :confused:
I had to replace a few of those and just used a metric allen headed bolt in a few locations. I guess hex headed fastener is an option, just use a washer under the head so the heads don't dig into the soft aluminum.
I had to replace a few of those and just used a metric allen headed bolt in a few locations. I guess hex headed fastener is an option, just use a washer under the head so the heads don't dig into the soft aluminum.
Thread Starter
Instructor
Joined: Aug 2002
Posts: 118
Likes: 0
From: Monongahela PA
Re: Question for the Experts! (qwerty111)
After reading my post, it is obvious I didn't make it clear that it was the torx intake, etc. that were the problem. We all know that the head bolts aren't torx.
Thanks 89 Paul in Cal for seeing through my oblique phrasing.
Thanks 89 Paul in Cal for seeing through my oblique phrasing.
Racer
Joined: Jun 2002
Posts: 428
Likes: 0
From: Dallas Tx
Re: Question for the Experts! (qwerty111)
Torx head bolts are designed to take greater torque before failure of the bolt head socket than allen head bolts-- all else being equal, ie, same grade of bolt. They are a good design used widely in aviation and aerospace applications.
(Read the thread in this forum about stripped socket allen head stainless intake bolts from TPIS)
If the Torx bolt is breaking the torx insert of the socket wrench, either the tool is of poor quality or the bolt is severely seized. The latter is typical of dissimilar metals applications (steel bolts in aluminum heads or blocks) or high heat applications (exhaust bolts anywhere).
Liberal use of penetrating oil (eg, Liquid Wrench) and mild heat to the bolt along with patience, prayer, a light hammer, and strong arm usually will work eventually. Hopefully the aluminum threads will not strip out.
The best prevention is antiseize compound to all steel bolts going into aluminum threads or in high heat spots such as exhaust bolts. Curse the factory for not using enough.
(Read the thread in this forum about stripped socket allen head stainless intake bolts from TPIS)
If the Torx bolt is breaking the torx insert of the socket wrench, either the tool is of poor quality or the bolt is severely seized. The latter is typical of dissimilar metals applications (steel bolts in aluminum heads or blocks) or high heat applications (exhaust bolts anywhere).
Liberal use of penetrating oil (eg, Liquid Wrench) and mild heat to the bolt along with patience, prayer, a light hammer, and strong arm usually will work eventually. Hopefully the aluminum threads will not strip out.
The best prevention is antiseize compound to all steel bolts going into aluminum threads or in high heat spots such as exhaust bolts. Curse the factory for not using enough.
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: Question for the Experts! (tkrussell)
You have valid points...but in all honesty, a torx head bolt with an English thread is not very common and is needed for the lower intake. The uppers are M8X1.25 which is somewhat more readily available. Try to get a price for one bolt from GM and you will walk away swearing that they gave you the price for a set.
I am using stainless steel allen head fasteners for my runners and stainless hex-head fasteners for my lower. For the intended load, I think that stainless will suffice.
Always use anti-sieze on the threads and make sure the lengths are sufficient. A rule of thumb for thread engagement in aluminum is 2X the major diameter. And I follow that rule after having heli-coiled the threads in my upper ;)
Good luck, -Matt-
I am using stainless steel allen head fasteners for my runners and stainless hex-head fasteners for my lower. For the intended load, I think that stainless will suffice.
Always use anti-sieze on the threads and make sure the lengths are sufficient. A rule of thumb for thread engagement in aluminum is 2X the major diameter. And I follow that rule after having heli-coiled the threads in my upper ;)
Good luck, -Matt-
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Thread Starter
Instructor
Joined: Aug 2002
Posts: 118
Likes: 0
From: Monongahela PA
Re: Question for the Experts! (qwerty111)
Thanks to tkrussell and HighHopes85.
That's the input I was looking for. Your points are well taken and I will follow your advice. Appreciate your help!! :cheers:
That's the input I was looking for. Your points are well taken and I will follow your advice. Appreciate your help!! :cheers: