Michael,
You are right about the bronze guides. The machine shop owner
told me I would have to use new bronze guides if I wanted Teflon
seals. He cut them to fit his choice of seal. His stock just
went up.
Brian Sanborn
62 TR4 CT16260L - Groton, MA
My TR4 Restoration Web Site
http://www.net1plus.com/users/sanborn/Home.html
E-Mail: sanborn@net1plus.com
-----Original Message-----
From: Michael D. Porter [mailto:mporter@zianet.com]
Sent: Tuesday, February 08, 2000 2:26 PM
To: Brian Sanborn; triumphs@autox.team.net; kkrice@earthlink.net
Subject: Re: Valve guide seals for TR6
Brian Sanborn wrote:
>
> >that's right but Ted Schumacher recommends fitment of small
block Chevy V-8
> >valve seals if you're having the head redone.
>
> Andy,
>
> I second the motion... my TR4 engine has teflon valve seals on
the intake valves. I had it done along with hardened valve seats
when the head was done. Modern technology is a good thing....
especially if it does not show.
>
> My shop took the standard bronze guides and machined them to
accept teflon seals that they supplied to fit.
Not to make light of anything Ted Schumacher says, but this
probably
needs further clarification. For most Triumphs, cast-iron guides
are
standard, not bronze. If an early engine has them, they were
likely
installed as part of a prior rebuild.
It might not be a good idea to install stem seals on the cast
iron
guides, since both the guide and valve are steel, and very likely
need
more lubrication, hence no stem seals in the first place. Some of
the
worst-worn cast-iron guides I've ever seen were on engines with
stem
seals (earlier Ford V-8s with umbrella seals were notorious for
that,
especially as the engine got older and oil pressure dropped).
Bronze guides, however do well with less lubrication, which is
why most
aluminum heads have aluminum bronze guides (cooperative expansion
rates
is another reason) and so valve stem seals are a stock item for
them.
And, yes, the replacement bronze guides do need to have a groove
cut in
them since the most commonly available stem seal for that
diameter guide
snaps into place on the guide.
As for Kyle's original question about the stem seal interfering
with the
inner spring, that likely means that the stem seal chosen by the
machine
shop is inappropriate. If there are cast iron guides still
installed,
tell them not to put any on. If bronze guides are installed, they
must
machine grooves in the guides to accept a stem seal which will
fit.
Don't let them just press them on, because they will come off and
eventually get beat up between the spring retainer and the guide.
Cheers.
--
Michael D. Porter
Roswell, NM
mailto: mporter@zianet.com
`70 GT6+ (being refurbished, slowly)
`71 GT6 Mk. III (organ donor)
`72 GT6 Mk. III (daily driver)
`64 TR4 (awaiting intensive care)
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