I assume you really mean you had ARP studs not just grade 8. If not, as
Shane says, get them. A lot of the "grade 8" hardware out there is cheap
counterfeit stuff to start with.
I'd suspect something that's causing side load on the studs, like
insufficient torque, or something holding the bottom of the rocker towers
off the head. You said you have the overhumg towers--they can interfere with
the head studs and bolts. Make sure you have plenty of clearance under the
overhang. If they are touching the head studs they will put a nasty load on
both the tower studs and the rocker shaft. If it turns out that's the
problem, once you correct it, replace the shaft as well.
-----Original Message-----
From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
Of SHANE Ingate
Sent: Wednesday, August 23, 2006 11:13 AM
To: vinttr4@geneseo.net
Cc: fot@autox.team.net
Subject: Re: [FOT] rocker stud breakage
Uncle Jack wrote:
>I broke two rocker stand mounting studs, both times the rear one, this
>weekend and I haven't been able to find the smoking gun cause.
>
>grade 8 studs
>
>Can you think of anything I'm missing?
Grade 8 studs/bolts are not rated for shear, so in a head they are as likely
to break as grade 5. I'd recommend ARP.
Sorry I cannot provide any diagnostics. Sure you didn't dribble rottweiler
loctite in the rear stud holes?
Shane Ingate, neophyte Dr Watson, in Maryland "Anyone can restore a car. It
takes a real man to cut one up."
|