On Tue, 19 Mar 1996, Richard Hauser wrote:
> The second head came from my parts car. When I pulled it the
> valves looked better, but I don't know what constitutes loose
> valve guides. (by the way these are 1275 engines) The book says
> that guides should be replaced if they are very loose and allow
> lateral rocking. These are a little loose, but don't really
> allow any rocking. Will the oil from the valve cover come down
> these guides into the cylinder? There aren't any seals on 1275s.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The oil from the valve cover WILL come down the guides, unless there's
something preventing it from doing so. I don't know what year your 1275
is, but on the '74, there are indeed valve seals, on the intake valves
only, if I remember correctly. Vizard (whom I tend to trust, even though
he seems to most strongly endorse those products which he sells)
recommends the later-style "mushroom" valve seals on the intake valves,
and no seal on the exhaust. A seal is particularly needed on the intake,
because it is under vacuum some of the time. The exhaust, OTOH, tends to
be under pressure, so there won't be nearly so much oil finding its way
down. The negligible amount of oil that will find its way down the
exhaust stem will serve to help conduct heat away from the exhaust valve -
especially on #2 and #3, that's A Very Good Thing.
Oh, and for reference, the first time I did the head on my Midget, I
replaced all the guides and seals, but it still smoked like crazy on
deceleration. Valve stems can be worn out too, I think. And I couldn't
detect any rocking on mine, but it still burned oil.
Actually, I would be interested to find others' opinions on where minor
wear ends and leakage begins around the stems.
Cheers!
Michael Chaffee
mchaffee@ux1.cso.uiuc.edu
CCSO's secretary has officially disavowed any knowledge of my actions.
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