Bill Miller wrote:
>
> I also set them while running. It is very easy, I never have once got
> burnt. If you have ever had the valve cover off while the engine is
> running, you will see that the spitfire engine does not spray oil, it more
> or less dribbles it up there.
>
> IMHO, running is the only way to correctly set the gap. You will never get
> the exact place on the lobe by rocking the car, in gear to get to the "high"
> spot. But you will running.
Okay, Bill, what's the hot lash specification and for what engine? That
was the original point. The guy asking didn't know if the published lash
was hot or cold. It was that simple.
Sorry, but this persistence in recommending checking the lash hot is
going to ruin some engines, unless you and others are willing to specify
the correct hot lash for the engine(s) in question. You and others are
contributing to confusion unless you give a hot lash spec.
I apologize if I seem to be insistent on this, but not a single poster
recommending setting lash while hot has provided a spec for doing so,
for any engine. If the cold spec is used when the engine is hot, the
valve train is going to be damaged. Period. Without specific hot valve
lash specifications, I consider recommendations to do so to be dangerous
and ill-advised--and a disservice to the uninitiated on this list.
Let me give an example. Twenty-five or so years ago, I spent a lot of my
time rebuilding VW air-cooled engines, but wondered why the valve lash,
cold, was only 0.006". So, I set the lash correctly, cold, then ran an
engine up to operating temperature and checked the lash hot. It was
0.015" on the intakes and 0.016" on the exhausts. After a couple of
tests, I could be fairly certain that those figures were correct when
hot. However, if I had set both the intakes and the exhausts to 0.006"
when hot, in the belief that setting valves to that spec, when hot, was
best, I would have burned up every engine I built.
My earlier point was that the suggestion to set valves hot was useless
without a hot spec. That hot spec is _different_ than the cold spec, and
further, if the cold spec is published, the ordinary user should set the
valve lash when the engine is cold. Period. No argument, no niggling
about details, or arguments about the "best way" without the data to
support that view.
There are a lot of people on this list who are not experienced mechanics
and desire simple, straightforward advice about how to maintain their
cars. In this case, simply how to set valve lash. This is an
extraordinarily simple issue. Don't complicate it without providing
_all_ the necessary correct information. If you recommend adjusting the
lash hot, provide the correct specification. If you don't have that
spec, just cease and desist. Other people's are at stake.
Cheers.
--
Michael D. Porter
Roswell, NM (yes, _that_ Roswell)
[mailto:mporter@zianet.com]
The gulf between content and substance continues to widen....
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