Do Head bolt threads get lubed before installing?
 

I did a search about it and got conflicting answers, the book I’m reading “how to rebuild GM LS-Series engine” by Chris Werner doesn’t say or I missed it. But what I've read everybody argees on lubing the underside of the head bolt.
Installing Head bolts do the threads get lubed or a light application of engine oil? :confused:

What bolts? ARP or GM?

That would be GM bolts.

no, not that i know of. I didnt for my heads that used new GM bolts.

It wouldn't hurt. They come with loctite on them, and I ususally wire wheel that $hit off, and use SAE30 oil on threads and underneath head. But 90% of the time, I use ARPs.

You can go either way. I always use some engine oil under the head of the bolt so the bolt head will not gall on the aluminum head. The important thing is to do all the bolts the same way, so that all the bolts will get torqued the same. Although torque to yield is a little more forgiving. It is more important to clean out the bolt holes before installing the bolts.

Gm reccomends a "special lubricant" for the head bolts. It's plain ole blue threadlocker. New GM bolts come with a pasted on threadlock, but I put a little blue on also. Torqued fine and it doesn't leak.

I'd take one of your old head bolts and grind some notches in to the threads (like a tap) and run it in/out of each head bolt hole to clean them out. The notches will help clean gunk out.

I have thread chaser that I orderd form Sumitt espically for these bolts 11mm
x2.0 the part number is 912-0011 if any one is interested.
Also the book calls for a torque of 15ftlbs + 90 degrees after the torque on the M11 bolts, is that right sound a bit much too me. My engine is an "03" Gen III

gm bolts need no lubricant. with the 03 gen 3 it might have the short head bolts, if it does not the old style have 2 short bolts on the ends and they get 15lbs plus 50 degress of twist. all the others are 15lbs 90 degrees. dont let people confuse you, because the old style of bolts were 22 lbs and 76 degree and only 22lbs and 34 degrees for the two short bolts. like i mentioned that is for the old bolts.

Because the bolt preload is measured by an angle and not a measured torque value, no lube is required as it will not affect the final preload of the bolt.

I do not lube stock bolts, I like keeping the loctite on them. I use a half shaved down stock bolt to clean out each bolt hole, make sure it's completely dry and free of debris. Then TQ as instructed.

I usually recommend my customers at least get the ARP bolts. Stronger than stock, don't require any angle TQ'ing BS, and a little 30wt oil on them and their good to go.

IIRC, Alldata said to torque all M11 bolts to 22lbs + 90*. Then do 90* for the big bolts, and 50* for the short end bolts. Then just 22lbs for the M8 bolts.

For those of you referencing my book, don't forget to take a look at the orange correction sticker on the first page regarding the head bolt tightening step in Chapter 8. The specs listed in the appendix are correct.

To answer your question, install new GM bolts as-is, no lube or additional threadlocker needed, using the (corrected) specs quoted in my book. ARP or otherwise, follow their instructions for both lubrication and tightening.

This is the correct method. No lubricant with stock head bolts is needed or recommended. Torque angle does not require lubricant as the thread pitch determines bolt stretch.

Shane

I bought your book from borders the first week it came out!
Thanks

No... thank YOU! Hope it's been helpful.

Thanks for chiming in Chris I didn’t think the author of the book would reply; great book lots of info. I was going to brush on a light coat of oil just to keep corrosion to a minimum but not now.

Thanks for the compliments. Good rationale on the corrosion protection but GM LS head bolts don't corrode as far as I have ever seen. I'm sure they are a very specific alloy to prevent that, especially in a steel-to-aluminum contact situation.

Best of luck on the build!

stock bolts arent that bad to use.
i use the sharpie method to mark my bolts and all is well.
i have head studs on my new build, only becuase they came with my block.
its all dependant on the power level as well.
i wouldnt use a stock bolt on a 900hp boosted setup, but for the average head and cam guy, that 300 bucks in studs is better spent elsewhere.

The corrosion protection looks like GeoMet which fairly standard practice at GM. It's designed for excellent corrosion protection and good interaction with dissimilar materials.