OK, this is "weirding me out" a little bit...

[V8Rumble]

Here are the basics - I'm swapping an '08 L92 into my GTA, currently pulling the original rod bolts in favor of ARP rod bolts.

What's happening is that I'll break one of the rod bolts loose from it's initial fastened torque, unscrew it several revolutions, & it will suddenly feel as though it's "done", it's ready to pull out. If I try to pull it out, it'll move maybe 1/4", but it absolutely won't pull out. What I need to do is to pull it out that 1/4" or so, and then start unscrewing it again - that allowed me to remove the 1st bolt that I pulled (picture below):



Does that bolt look relatively "normal" for those of you who've done this before??

Thankfully, the new ARP bolt went in just fine, but as I've started the 2nd bolt, it's doing the exact same thing that the 1st one did (exc. it seems that it doesn't want to "catch the threads" on the 2nd section like the 1st one did), & since it seems pretty weird to me, I figured I'd stop right where I'm at, & make sure that I'm not doing something wrong (although how you'd "do something wrong" by undoing one bolt at a time seems a bit counterintuitive...).

I realize that these are SINGLE-USE-ONLY bolts, made to go to a certain torque, & then to have an angle-gauge used to get the bolt stretch exactly right, but I'm thinking that following the directions that ARP gave me should give good results, correct? (Remove old bolts 1 at a time, put a bit of moly lube on the new bolt, tighten to 45 ft/lbs, loosen, tighten to 45 ft/lbs, loosen, & then tighten it to 45 ft/lbs for the final time & move on to the next one.)

Thanks a bunch guys, any help/advice you can give is MUCH appreciated...

[V8Rumble]

Has anyone run into this before???

One more thing that I thought of - the 2nd bolt I've tried just turns & turns, it acts like it isn't going to "catch the threads" the 2nd time at all. So, I moved on to another bolt, which came out like the 1st one did (meaning relatively easily, given the "trick" that you have to use).

EDIT: Well, since no one answered, I said what the hell & just blazed the trail forward. I figured that the stock bolts just had the ferrules that were mentioned in this thread, so I paid particular attention to how all of the stock rod bolts came out. I didn't see any indications of shavings or slivers of metal that would lead me to think that part of one of 'em didn't come out, so I'm guessing that I'm probably fine.

There were at least five or six of the little buggers that "didn't want to catch the threads on the 2nd section" as I mentioned above, but I figured out a way to get each of them out regardless - I found that if I used an open-end wrench that fit around the shaft of the rod bolt (but one that was smaller than the head), then I could exert a moderate & steady upward pressure with one hand, while operating the ratchet with the other. Every one of 'em worked themselves out when I did that.

I ALSO paid strict attention to how the ARP bolts went in. Granted, I was using the ARP moly lube, but I threaded each of them in using only two fingers, & each one of them seemed to thread in normally. I did the standard "tighten/loosen/tighten/loosen/tighten/" sequence that the guy on the phone at ARP told me to use, then I spun the engine around one more time so that I could check each bolt for proper torque one last time.

I don't know that there's anything "earth-shattering" in this thread, but maybe this will help someone else who finds himself in the same spot...

[cam]

Hmm odd but I wouldn't worry about what came out so long as the new ones are in and torqued forget about it your good to go IMO.

Out of curiosity I was searching out info a while back about the rod bolts in the L92 engines and came up with nothing. I did however find out that LS3's use a 12. grade rod bolt ( same as LS7's ) which are spun to 7K RPM stock so I was hoping to find that the L92 shared these same bolts seeing as the bottom ends between the L92 and LS3 are practically the same.

So I'm curious as to why you swapped the rod bolts being a new engine did you uncover some info about them that stated they were not up to par?

[V8Rumble]

No, I never heard anything that gave me cause for concern, but I never heard anything about them being better than the average stock rod bolt either... I just figured that since I'm not likely to be able to do this again in a year or two, that new rod bolts would be cheap insurance/help with longevity (since they're probably the most-stressed part in the engine).

They're probably overkill in my application, since I'm retaining the stock cam (until the aftermarket catches up to VVT) & not planning on winding it past 6,500 or so, but the cost is pretty low for what they do, so I decided to go this route...

If I'd heard confirmed info that they were the same bolts used in the LS7 (your post is the 1st that I'd heard that was even a possibility), I very likely would've left them alone.

[Scoggin Dickey]

The L92 and LS3 use the same bolt. The LS7 is different

[cam]

Thats good to know thanks!

My info came from GMHTP Nov 2007 issue that profiled the LS3 and on page 38 it says;

"At the big end of the connecting rods, the bolts have been upgraded to 12.9 grade material similar to what is used in the 505hp LS7"

I just dug that up now but that article peaked my curiosity about the L92's because they are so similar and I was thinking of buying one at the time so wanted to find out what needed upgrading and what didnt. Sounds like the stockers are plenty strong although I cant see how upgrading to Katech or ARP could hurt its just not mandatory as the older LS1's are.

[V8Rumble]

Originally Posted by cam

My info came from GMHTP Nov 2007 issue that profiled the LS3 and on page 38 it says;

"At the big end of the connecting rods, the bolts have been upgraded to 12.9 grade material similar to what is used in the 505hp LS7"

I can confirm that - if you look closely at the bottom bolt in this picture I took, you should be able to see the '12.9' there...



Thanks for the confirmation SD.

(Dang it, NOW I'm wondering if I wasted 80 bucks & the time I spent...!)

[cam]

Well like anything someone has to be the first to confirm speculation and you did that for me and anyone else who searches this out so thanks. I'd still bet that you made an upgrade here and not an expensive one at that so for the unknown factor it was cheap insurance

[Scoggin Dickey]

There is no reason to regret your decision, you still upgraded.

[onefastfox]

yes the bolt is normal and in case you where wondering still, the LS3 rod bolt uses two different thread sizes and diameters to control and localize bolt stretch.

[V8Rumble]

Very cool, thank you! I knew that it had to serve a purpose, I just didn't know what that purpose would be...