REFLECTOR:Checking valve guides ...

[Nolan Frederick]

Dear Jim,
    Here's a little bit about valve guides you may want to consider:  I've
worked on lots of automobile engines and motorcycle engines, not on
Lycosaurs. But they aren't really all that different from air-cooled MC
engines.  It is common practice nowadays to put these rubber boots on the
valve stems of  automobile engines especially.  I suspect this practice is
followed to minimize the ingress of oil into the cylinders and thereby
delays the smoking that we used to see quite a lot of back in the old days.
Now, I can see putting those things on the intakes but NOT on the exhaust
valve stems.  The exhaust stems are always under positive pressure from the
escaping gasses so we don't see oil being sucked into the cylinders via the
exhaust stem/guide clearance.  In fact, If those booties aren't on the
exhaust stems and there is some unburnt oil in the exhaust gas it could
serve to lubricate the exhaust stems.  I use a little MM in my gas
occasionally just to increase the likelihood of getting some on my exhaust
valve stems.  I doesn't hurt.   I learnt engine work from an old alcoholic
race-car engine builder and he told me that if one pulls a piston from a
cylinder and then puts it back it will pump oil like crazy.  The rings won't
seat unless the cylinder glaze is broken/removed and new rings are
installed.  So, if it were me, I certainly wouldn't be pulling my Lycosaur
cylinders to check my valve stem clearance.
Best wishes and some good luck too.
nolan.

----- Original Message ----- 
From: "Jim Sower" <canarder@frontiernet.net>
To: "Cozy Forum" <Cozy_Builders@mailman.qth.net>; "Velocity Forum"
<reflector@tvbf.org>
Sent: Sunday, March 14, 2004 10:44 PM
Subject: REFLECTOR:Checking valve guides ...


> I've got a problem for some of you Lyc doctors ....
>
> I've been hearing off and on about checking valve guides on Lycs
> for too much or too little clearance - either ready to seize or
> burning oil.  I'm doing my annual now and thought I'd check the
> guides on my angle valve IO-360.  Went to the local IA and he
> said that if he checks them at all, it's pull the jug, remove
> the valve and mic it.  Seemed a little much since I thought what
> I'd been hearing involved pulling the spring, wiggling the stem
> and estimating the severity of the lash problem.
>
> Is the "quick and dirty" check, I've described common practice?
> If so, how exactly, does one perform the inspection?  If not,
> how common is pulling the jugs, field stripping them and mic-ing
> the guides?  Do I need to bother at all with 500 hrs on the
> engine and two jugs with 100 and 200 hrs on them?
>
> Need some straight answers .... Jim S.
>
>
> _______________________________________________
> To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>