I managed to somehow separate the head from the washer portion of two of the bolts. I went to my local parts store and found Grade 5 bolts that are short 1/16 of an inch are not threaded on the upper portion enough to be solid within the rocker arm and is a hex head instead of a nut.

What I'm wondering is, since the rocker arms are rollers that bolt doesn't do much except keep it in place, I mean all the force is directed around the rocker as it rocks meaning a Grade 5 bolt is enough, right? It was identical thread so I'm hoping it holds...

 

I wouldn't do it, go to the dealer and get the right bolts.

 

Different material, different fatigue life. Get the correct bolts. How on earth did you break them?

 

complete fluke of nature... I was just torquing them down and then I noticed it didn't click... so I backed off let it reset tried for a click and instead got something completely different sounding which came from the bolt itself.

Oddly enough, I've gotten replacement ARP studs and bolts for various things here and there and from the looks of it, this grade 5 is stronger than the weak bolt it replaces...

Either way it's temporary, I'll try to avoid spinning up too much.

Also on another note, it's 22ft/lbs and it's a roller rocker... just how much force does it experience when only 22ft/lb of torque and some locktite holds it in??? Just throwing that thought up there... the stocker is no grade 8 bolt... let alone a grade 5...

 

If it were my car, and I had to drive it, I would do it for sure. Then I would call my dealer asap and get the right ones on there. But I wouldn't recomend it to anyone.

 

It experinces the force of a rapid lift lobe, a 7 to 1 fulcrum and your spring compression rate. The torque spec to tighten it has nothing to do with the anticipated load, you'll notice they are long bolts to grab enough surface area in the head for the anticpated load.

 

Well I've changed them, and the replacements held on for the 200 miles I had to travel.

Luckilly the ones I got were almost the same length, about 1/16 of an inch shorter but the tip of the bolt isn't threaded anyways so it still had plenty of thread to grab.

I think I figured out why I wrecked the bolts, I had put locktite on them but on a few, the loctite was a bit excessive and leaked down the threads I figure it skewed the torque readings enough to have loctite instead of motor oil on the threads to cause me grief. I redid the driver's side completely as the passenger side was done so damn carefully and was perfectly quiet compared to the odd tick I could pinpoint from the driver's side.

All is well now I think with the stock bolts in. As a note for anyone torquing down rocker bolts... make sure the threads are lubed up with OIL and not loctite else you end up overtorquing them especially if you have a high mile engine.

 

Not sure if it will help any but here is a scan from the factory shop manual. It only suggests to lube the flange surface of the bolt with oil. It mentions nothing about oiling the threads or using any loctite. I recently installed rockers on my motor using this method and added just a drop of loctite on the threads for peace of mind. Torqued them to the recommended 22ftlbs. How is everyone else doing it?

 

broke one after header install......went to gm and it was 2.98 in stock

 

"How is everyone else doing it?"

I put a dab under the washer portion of the bolt and none on the threads. For ported heads I use teflon paste on the threads of the intake rocker (to stop oil coming through).