John:
They are high tensile steel. If you want an economical
replacement (but non-stock) then socket headed cap screws with the black
oxide finish will work just fine, and cost about $1.25 each at your
local ace hardware (or bolt depot if they do not have a suitable
length).
I would NEVER reuse any stud (nose gets longer) to save a few
dollars, and have always used new studs (nose getting still longer) in
the interest of doing the job right (nose now reaches to computer
monitor).
Seriously, I have reused existing head studs, but they are a
highly stressed item and if they are corroded/rusty then they simply
must be scrapped (strength falls off DRAMATICALLY as the stud corrodes).
If they are in good condition then they probably can be reused.
Main bearing caps and rod bolts are riskier however, because if
they fail they take out a very expensive bottom end, as opposed to just
losing a head gasket. In addition, the bottom end is cyclically loaded
(i.e. it takes a real pounding) while the head stud load is essentially
static. Once again, socket headed cap screws from the hardware store are
a very reasonably priced alternative. The black oxide socket headed
screws are grade 10, and you simply will not get a tougher fastener.
Down side is that they have virtually no corrosion resistance, and you
need the appropriate tool bit to torque them (And use a torque
wrench!!!)
The bottom end is highly stressed and catastrophe prone, so
avoid reusing bottom end fasteners. While the likelihood of failure is
low, the cost of a failure is EXTREMELY high. Too rich for my blood.
Vance
-----Original Message-----
From: owner-6pack@Autox.Team.Net [mailto:owner-6pack@Autox.Team.Net] On
Behalf Of John North
Sent: November 26, 2007 10:16 AM
To: Triumph 6 Pack
Subject: [6pack] Head studs
Should I replace the head studs or re-use the old ones? They look to
be in good shape and the new ones are like $10 each, 14 needed.
Seems like no-one stocks the two longer ones anymore either. I did
raise compression to 9.5:1, which is a factor. I pretty much
persuaded myself to by new, but maybe some who have BTDT can tell me
it's OK to save $140... What is "special" about these? Are they a
generic product available outside the big 3?
John North
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