Re: Oil

[Angus Holliday <trstag@domain.elided>]

At 08:01 AM 3/9/99 -0700, you wrote:
>Hello Walter,
>
>    Thank you for that great explanation on siezed valves.
>
>This prompts a question that has been burning for quite some time more
>along the line of your valve/oxygenated fuels explanation.
>
>    The Stag engine does not use valve stem seals like so many other
>cars.  I think that the original valve guides were steel?,
They were originally steel, we usually fit bronze when rebuilding. I don't
really like
the "sleeving" of guides.  


 at least that
>is what came out of my last set of heads that appeared untouched.    My
>engine builder told me that steel guides with steel valves is a bad
>combination just for the reasons you state, we have hi-oxy fuel in
>Colorado 6 months out of the year.  I have had my heads reworked with
>bronze guides, but have been wondering if anyone recommends adding stem
>seals.
The bronze guides are porous and retain oil.  The varnish/glue of the oxy
fuels will not be affected by changing..however
the bronze guides help prevent sticking from the lack of lead lubricantion.
This was first noticed in Jags.  Usually it didn't lead to
failure but a rough idle due to hanging up at idle speed. 

.  My engine builder says it is up to me, but that the
>engine would run a slight bit cleaner with stem seals.  Seals would need
>to be high temp variety and not the standard rubber caps.
>    I also believe that with bronze guides and stem seals, the Stag
>engine will clean up a bit on particulate emission, as we in Colorado,
>like Arizona, have a Clean Air emissions program and auto tests
I would be hesitant to fit oil seals as the stem is already well shielded by
the tappet design and the guides do need to get some oil.
I don't know of anyone who has tried it so I can't say exactly what the
results would be.

. Which
>brings up the question of how you deal with emissions tests in AZ on
>Stags??
Pima county (Tucson) and Maricopa county (Phoenix, Tempe, Mesa, Scottsdale)
have yearly tests on a dyno and at idle.  They
also check for emission equipment .  All cars after 67 must pass, though the
standards are liberal for older cars ('67 is 5% I think)
The Stag is about 2% and 250ppm as I recall; not that hard to accomplish
with electronic and good Strombergs.
>
Walter Holliday
Stag Specialists
850 East Teton #3
Tucson, AZ  95706
520 792-0294
trstag@domain.elided