1988Bullitt

I am curious to see what the consensus is on oiling or not oiling stock replacement GM torque to yield head bolts on the LS7.

As I hope everyone knows applying engine oil to the threads and to the underside of the head of the bolt decreases friction and increases clamp load when torqueing these fasteners. Stock LS7 head bolts have a thread sealant/locker on the threads so my thinking would be to only oil the underside of the bolt head.

From what I could find the service manual did not specify this “oiling” for the LS7. Many other manufacturers do require this and I know this is a common practice / recommendation of machine shops I have dealt with in the past.

I am curious to hear what others on here have done when re-installing their LS7 heads with new stock torque to yield bolts.

Thanks

c5racr1

I used arp bolts, it uses its own lube.

amdoverclocker

http://arp-bolts.com/p/arpultratorque.php

1988Bullitt

I appreciate the comments regarding ARP bolts and lubricant; however the question is not regarding ARP bolt, studs, etc. If it were there would be no question, lubricate the threads and underside of the bolt head. I am curious what others do with regards to Stock GM replacement torque to yield bolts.

Vito.A

If you decide to use OEM bolts, then you must use the GM torque procedure along with the GM thread sealer.

0Anthony @ LGMotorsports

Anything applied to the bolts as a sealant/lubricant is going to change the total toque applied to the bolt. That is why on ARP's site you see what the specs are vs what lube is used.

Vito.A

GM assembles these engines at the Performance Build Center in MI. They automatically torque everything using a computerized machine called a "Spindle Multiple" manufactured by Atlas Copco. It also records all the items torqued with the exact torque value used.

The reason most of us use ARP head bolts is we can duplicate the necessary steps required to properly stretch the fastener and insure a good seal, not to mention the bolts are higher quality and reusable. It is difficult for most of us to duplicate GM's procedures. GM does publish procedures for their field technicians, but these are a compromise when compared to the original assembly.

rio95

I thought the OEM bolts come with sealer already on the threads??

I got ARP bolts too. They're good and inexpensive.

Mark2009

If you buy them by the package (complete set for one head), yes.

If you buy them individually, no.

For the OP, I would not use the oil. I doubt it would make any difference in torque value since you are not tightening to torque (but to rotation/stretch), but it might make a difference in retention (bolt movement over the course of long term operation).
.

1988Bullitt

All good information.

I have already cleaned my threads with the ARP thread chasers, brake clean, and compressed air. I have the new GM factory bolts with the sealant/locker already pre-applied and I will be following the above procedure lifted from the shop manual for installing the torque to yield bolts. Not being cocky, but this isn't my first time doing any of this. There are some people on this forum with copious amounts of LS knowledge and I am always curious to hear about others experiences. More than anything I was just curious if anyone had ever done any studies on torque, angle and clamp load with oil under the head vs. no oil on the LS7. I know what I will be doing personally, but I still love opinions.

Nowanker

Just for a grin... install the bolt dry to 22lbs, mark its position, remove it, oil under the head, retorque to 22lbs and compare the relative positions. I haven't ever made the comparison, but I'll bet at that low torque figure the positions are essentially the same. Especially in the context of an additional 160 degrees.
I'd probably oil under the heads, just because the machinery might appreciate it.
Just my $.02

1988Bullitt

Well excuse me for starting a talking point; I thought that is exactly what forums were for. Thanks for the jab about my knowledge too, because you know me so well and my background. I also appreciate your input on GM's inferior fasteners and plug for ARP's fine fasteners considering my question was regarding what others do with stock bolts.

If your answer is you don't have input on stock bolts because you don't like them and you choose to use ARP's that's great. ARP makes a great fastener. Either choose not to comment or say that you don't know because you use APR's...

Again, I am just curious what others have done for my own inquisitive mind.

1988Bullitt

Good idea for a trial, GM would have done a similar CPK study when setting up their equipment and determining how much the thread locker, thread friction and bolt head friction effected the torque, angle, and clamp load.

To get any reliable data though you would have to do several trials with fresh bolts and blocks. Since the stock bolt threads have the coating pre-applied you couldn't use them again since you wipe it after one use. Evidently GM didn't think a lubricant was needed under the bolt head when it comes to the service manual procedure.

I am curious to hear from people that saw their engines built at Wixom. Was there any lubrication on the underside of bolt head or the mating surface of the cylinder head?

Nowanker

So now one plays with expensive engines? Play, and the factory thread sealant is now gone. [/QUOTE]

Sealer can be re applied, but If the concept is too scary for you... use any bolt of similar size and see just how small 22lb is for a torque value. The whole theory of angle torque and TTY relies on the measured stretch induced by turning the fastener a specified amount after some nominal starting point.
I'll bet that the starting point for that 160 degrees additional twist will be EXACTLY the same either with or without lube. The lube would have no effect on the angle torque, other than giving smoother motion while tightening. If you've ever actually used an angle torque gauge, you'll agree that's a good thing.

MyLS1Hauls

Exactly why I prefer ARP studs over either stock bolts or ARP bolts.

3X2

Put this in the FWIW catagory. Of the 100's of LS heads I've installed, all have been with stock head bolts. These are mostly stock engine or maybe a h&c package. If I were to build a all out race engine, ARP would be the way to go. As far as cleaning the threads in the block, I use an old head bolt that I removed whatever remining sealer is on it and cut some flutes lengthwise with a wizz wheel.

1988Bullitt

You need to re-read the posts, I never suggested doing any trials on my engine, I was asking if anyone else had! I agree I am not going to put the threads on my block through multiple cleanings (and potential weakening). That was suggested by another member. As you can see those were not my words, you quoted Nowanker... Still no reason to pick on a guy for a suggestion. As far as picking on him for not being able to "Quote" re-read your sentence... I wouldn't pick on anyone when you can't even use the correct "You're".

CyberZ

Not trying to get in a pissing match with anyone here.

I was about to use stock replacement bolts on my build until I found the procedure GM has its techs follow in the LS7 service manual calls for a 600 dollar tool to torque the stock torque to yield bolts. I thought it was better to use the higher quality arp bolts and lube at that point and my snap-on torque wrench as I have had good luck on other engines going this route. Just my opinion though.

1988Bullitt

Nothing wrong with using ARP, they make a great bolt! This is what I have always used on my torque to yield fasteners.

Nowanker

...Looks identical to the one Snap On sold me. I'm afraid to look up what I paid.