Rocker Arm Bolts Snapping

[Herezja]

Having an issue. Putting the 360 back together after a Edelbrock Performer Cam and Lifter upgrade (2132) and the rocker arm bolts are giving some trouble. Most of the bolts have gone back in fine, but when we try and torque (to spec) the #3 intake rocker bolt, it just snaps right off. We are using the same size bolts that came out: 5/16-18 x 1.25 grade 8. We have tried honing/cleaning it out and even shined a light down in there looking for obstructions, but there is nothing. We have even tried cutting a bolt down to the point that just a few threads go in and end up with the same issue. Whatever bolt we put in there just wants to snap off when tightened down. Anyone have any ideas on this or seen this happen before? Could the hole have shrunk or something? Could it be a different size than all the others? Its really strange....I even stumped the guys at NAPA and Summit.

1983 Jeep Cherokee Laredo
AMC 360 V8

We are adding/replacing the following:
Edelbrock Performer Cam and Lifters (2132)
Edelbrock Performer Intake (2131)
Edelbrock Carb (1406)
Edelbrock Double-Roller Timing Chain
Various Gaskets and Lines, of course
Water Pump
Oil Pump
Fuel Pump

...I think thats it.

Any thoughts are appreciated.

[Herezja]

Jeez...nevermind. My buddy (chevy guy) is working on it right now while I am at work. Didn't realize he hadn't rotated the engine to turn the lobe down on that intake. Everything is good now.

Rule of thumb...when torquing rocker bolts, make sure to rotate the engine as you go

[serehill]

Something's not right.

[Herezja]

Something's not right.

Do tell.

[serehill]

The only thing there is spring pressure. I have done tons of them without breaking any bolts or turning any motors. What torque were you running them to? I 'm not sure of the issue but it makes no sense to me. I've never rotated an engine to do that & the only thing you're relieving is spring tension. If spring tension were to break the bolts the why does it only do it when tightening the bolts? just running would do it.

[Herezja]

Just going on what I was told on the phone. I will have further details tomorrow evening. Will post up after I see it first hand and talk to him in person. Whatever it was, once he rotated the engine and dropped the lobe on the cam (as was described to me), it torqued as it should. Don't know, maybe the lifter wasn't fully seated, preventing the rod from fully seating, and so on? Not sure.

[serehill]

Me either just really curious could be something obvious.

[Herezja]

Me either just really curious could be something obvious.

Yeah...I am pretty curious to see what was going on first hand myself. Unfortunately, I can't get over there tonight, but we are hoping to get the majority of what's left back together tomorrow night and tighten up any loose ends (no pun intended) and fire it over the weekend sometime. I'm just glad things started falling into place....I was beginning to get a little worried. Will let you know what comes about tomorrow. Hopefully when I find some time, I can get a few crappy cell pics posted up of the work too.

[Stuka]

Sounds like your push rods are too long. There is no need to rotate the engine to torque those. Are you using differ rockers? Different ratio or the like?

[Herezja]

Sounds like your push rods are too long. There is no need to rotate the engine to torque those. Are you using differ rockets? Different ratio or the like?

That's what I thought too. Not using different push rods or rockers. All the others torqued just fine, though. It was only the #3 intake bolt that was causing issues. I will have further details this evening. I am suspecting that the lifter wasn't quite seated all the way, which was making the rod not seat properly, and so on. Not sure though. Will get all the nitty-gritty this evening.