Rocker studs came loose

[TimAT]

I just had a thought- first one today too and it's 11PM:trumpet:

Most bolts have a little shoulder right where the head meets the threads- may be pretty flat, but if those ARP studs are anything like the factory studs, they have that little shoulder too. It was for centering the guideplates. Make sure your guideplates have a chamfer that the studs seat in. If they are just flat steel stock that's been drilled and shaped like the factory ones, that could be why they came loose after torque. If the plates are upside down, they won't have that chamfer against the stud. If you look close at the studs I bet you can see what I'm talking about..

:harhar:

 

[73 Mike]

I just had a thought- first one today too and it's 11PM:trumpet:

Most bolts have a little shoulder right where the head meets the threads- may be pretty flat, but if those ARP studs are anything like the factory studs, they have that little shoulder too. It was for centering the guideplates. Make sure your guideplates have a chamfer that the studs seat in. If they are just flat steel stock that's been drilled and shaped like the factory ones, that could be why they came loose after torque. If the plates are upside down, they won't have that chamfer against the stud. If you look close at the studs I bet you can see what I'm talking about..

:harhar:

That's an interesting thought. I'm not home today so can't look. As I recall, the shoulders of the studs were flat, but I'm not certain about that. I am certain that the guide plates did not have a chamfer. Just a straight sided hole.

I'll let you know.

 

[mrvette]

I just had a thought- first one today too and it's 11PM:trumpet:

Most bolts have a little shoulder right where the head meets the threads- may be pretty flat, but if those ARP studs are anything like the factory studs, they have that little shoulder too. It was for centering the guideplates. Make sure your guideplates have a chamfer that the studs seat in. If they are just flat steel stock that's been drilled and shaped like the factory ones, that could be why they came loose after torque. If the plates are upside down, they won't have that chamfer against the stud. If you look close at the studs I bet you can see what I'm talking about..

:harhar:

That's an interesting thought. I'm not home today so can't look. As I recall, the shoulders of the studs were flat, but I'm not certain about that. I am certain that the guide plates did not have a chamfer. Just a straight sided hole.

I'll let you know.

like you remember is the way mine was....straight, no DV8....


:smash:

 

[73 Mike]

I had my first chance tonight to have a look at the various parts. The rocker studs had flat shoulders but there was a small chamfer on the top of the hole in the guide plates. No biggie as the bottom side was flat

BUT

the plates are definately not flat. There appears to be a compound bend to them. All are essentially the same so I'm not sure if it is on purpose or not. The guidplates are from Comp Cams so I sent them an email. See what they have to say tomorrow.

 

[73 Mike]

I had my first chance tonight to have a look at the various parts. The rocker studs had flat shoulders but there was a small chamfer on the top of the hole in the guide plates. No biggie as the bottom side was flat

BUT

the plates are definately not flat. There appears to be a compound bend to them. All are essentially the same so I'm not sure if it is on purpose or not. The guidplates are from Comp Cams so I sent them an email. See what they have to say tomorrow.

Spoke to the Comp Cam tech guy this morning. In addition to those items that we already discussed, he also suggested the possibility of coil bind (which I don't believe to be an isssue) as well as harmonics. He also thought that loose threads in the one head was a real possibility that they have seen before.

I asked about a spec for acceptable warp to the guideplates and he wasn't aware of a specification. His suggestion was that a sheet of paper should not be able to fit under any bow (couple of thou I would guess). He did say that the guideplates are die pressed though so warpage isn't out of the question.

In any case, I'm going to try the "paper under the bow" trick to try to assess if it's an issue. If not, I'm going to try them out with the Locktite and keep a very close eye on them.

One usefull piece of information that he did provide was that there is no "up" to the plates. You can mount them either way and it won't make any difference. As such, I'll mount them with the part number dow so that a little more of the stud will contact the plate.