Justin Wagner wrote:
>
> Egil Kvaleberg wrote:
> >
> > On 8 Sep 1997, Tom Tweed wrote:
> >
> > > I'd have to say that the short answer must be, Do what the manual says.
> >
> > The manual says re-torque after 1000 km (or something thereabout). A
> > mechanically knowledgable friend says that the re-torque really should
> > occur after the engine has been properly hot - once is enough for things
> > to settle.
> >
> > This does seem to make some sort of sense to me - it is reasonable to
> > assume that the 1000 km thing was to make customer relations easier (and
> > also nicely coinciding with various other service and control tasks due
> > at that time for a new car).
> >
> > Other views?
> >
> > Egil
> > --
> > Email: egil@kvaleberg.no Voice: +47 22523641, 92022780 Fax: +47 22525899
> > Snail: Egil Kvaleberg, Husebybakken 14A, 0379 Oslo, Norway
> > URL: http://home.sn.no/home/egilk/ PGP: finger:egilk@sn.no
>
> Let's keep in mind that I started this portion of the thread on the
> question of HOW to re-torque.... not WHEN.... as all the old manuals
> are pretty clear about WHEN... but they're not clear on HOW... other
> than to follow the proper sequence...
>
> to loosen or not to loosen... how much to loosen... how little... etc.
> etc. JUST curious to hear people's opinions... I have not had any blown
> head gaskets nor damaged heads... but this does not mean my methods are
> the best...
>
> Justin
I'll jump back in here for a few last comments.
1. Differences in materials do make a difference in torqueing
methodology. (Differing expansion rates heat capacities etc.)
Best info indicates that for aluminium blocks and/or heads retorque
after cool down.
2. I have tried to total # of times I've had the head off the TR. Too
many times to be sure (a dozen?).
3. At least 3 gasket failures. One due to not retorqueing. One due to
undetermined causes. And this last one due to what I think after close
examination was the wrong gasket. Subtle differences in width of gasket
space between most closely adjacent cylinders).
4. Based on my experience this time I will retorque after bringing the
engine to operating temp and while still hot. Finding a 15 to 20 ft/lb
difference leads me to conclude that waiting any length of time increases
the risk of blowing a gasket. Less compression on the gasket = greater
possibility of leakage of compressed and burning gasses. Havn't worried
about backing off before retorquing - using a long owned bar scale torque
wrench - no worry about this thing just clicking on a stuck nut.
This particular leak was at a point immediately adjacent to a water
jacket port. Very samll amount of coolant leaking into cylinder (based on
no evidence of water in oil pan) but enough to cause miss at cold start
and idle (until liquid blown out of cylinder?) and enough leakage of
gasses to cause coolant foaming, but not enough to overwhelm radiator cap
seal, but some blow out into reserve bottle on shut down.
5. I will also follow the lead of our racing friend and adjust valves
when hot the next time I check. It will be interesting to see if this
quiets tappet noise appreciably.
6. As I said earlier so far so good. As usual driving to work daily and
she's running like a top. With the Pertronix in and everything adjusted
to the best oof my ability the thing starts like my F.I. Jag. Touch the
key and I'm off and running. It's still a thrill after all these years.
Deano
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