Hi Gents,
gut, wenn man Ordnung in seinem Jaguar hat: Ich habe den Autor gefunden, der die Schrauben da hineingedreht hat. Aus seiner Publikation stammt das obige Bild. Die sonst um die 50 US-Dollar verkauften kits bestehen offensichtlich aus nur drei Schrauben, die jeweils eine Art Unterlegscheibe halten, die ihrerseits in der Mitte zweier Stößelventildingsbums positioniert werden und damit beide an ihrem Kragen unten halten. Damit wird in der Regel die Auslass-Seite bepflastert, weil die heißer wird (Richtung Süden wird's, scheint's, auch im Motor heißer). Will man auch den Eingang zumauern, braucht man zwei kits - 100 $ oder so. Die Schrauben sind dagegen wohl recht günstg, man braucht aber sechs pro Seite. Gebohrt wird am lebenden Zylinderkopf, Ölwechsel anschließend wird empfohlen. Wichtig scheint mir der Hinweis auf professionelle Hilfe. Ohne einen, der sich mit diesen Dingen auskennt, scheint das Unternehmen waghalsig zu sein.
Hier ist der O-Ton Gunnar Helliesen von vor 10 Jahren. Ob er inzwischen seinen Jag verschrotten musste, weiß ich nicht, aber wir könnten ihn ja 'mal fragen:
An alternative XK Stakedown methodAn alternative XK Stakedown method
The conventional wisdom on the Jag-Lovers XJ-Lovers mailing list seems to be
that if your Jaguar XK engine develops loose tappet guides you should purchase a
so called Stakedown kit from a parts vendor and have it installed by a
professional Jaguar mechanic.
I beg to differ.
Before I go into details on how I solved the problem, here's a link to the
Jag-Lovers XK Engine Tappet Retainer Stakedown FAQ. Read it through before you
do anything else and come back here if you'd like an alternative view.
So you're back, eh? OK, here goes:
I live in Norway and none of the parts vendors around here had even heard of a
stakedown kit so I decided to do without. The Norwegian Jaguar dealer (yes, we
only have one) even recommended I do it this way.
The procedure is simple: Instead of drilling holes where they are not needed and
introducing lots of Big Pointy Metal Objects that could do a lot of harm if they
ever worked their way loose, I simply inserted a screw beside each tappet guide
holding it in place. When I say "I" I mean a friend of mine who knows his way
around a machine shop (he owns and operates one). Trust me on this one:
Recruiting help from a professional for this operation is not a defeat.
The procedure:
Click any image for a larger 1024x697 version (~180KB).
Note that when I describe in the text what you can see in
the pictures I'm referring to the large version of the
pictures.
Bild 1. Overview of the engine with the LHS cam cover off.
You can clearly see one screw in place and the grease for
keeping drill shavings under control. You can also see the
paper stuffed into every opening in the head to prevent bits
and pieces (and shavings!) from falling into the engine.
Before doing anything else you should make sure that all the
tappet guides are firmly seated at the bottom of their seats
in the head. This is easy enough to measure, just compare all
six (or twelve if you're doing both sides).
Bild 2. Drilling the holes. Each hole was drilled at an angle
just slightly cutting into the tappet guide itself. The holes
where then tapped and the grease removed. I spent several hours
making sure I got every little bit of metal shaving out of there
before I put the cam cover back on.
Bild 3. One screw in place. You can see that the screw is sitting at
an angle, the bottom end cutting into the tappet guide (but not
through it!). You can also see that the head of the screw is
holding the lip of the tappet guide, securing it firmly (yellow
arrow). The screw is secured with Loctite™.
You can also clearly see the damage done to the tappet guide by
its direct contact with the cam lobe, small chips are missing
around the inner edge (red arrows).
Bild 4. siehe oben. Job done and ready to put the cam cover back on. Note how
clean everything is, make sure you get all the shavings out!
Oh, and don't forget to remove the paper/cloth you stuffed into
the openings in the head...
After completing the job I immediately changed the oil and filter
without starting the engine first. I then drove the car for
one day and changed the oil and filter again just to make sure.
You should too.
Copyright © 1997, Gunnar Helliesen,
gunnar@bitcon.noIch hoffe, dass Herr Helliesen sich jetzt freut...
c-c
