After a busy xmas / new year period, I have finally got the head off the
XJS.
Was not anywhere near as bad as the last time when I did the other head 2
years ago.
Damage was much as I thought it would be, the exhaust valve seat on No6 Rh
side had broken up and got pounded to pieces. Does not look like any damage
to the bore and the piston should clean up ok.
The head will definitely need welding and machining. From what I can see, 2
ex valves will need replacing. But I will thoroughly check all the valves
and seats before a final decision is made.
Next job will be to remove the timing cover. Hopefully this will be fairly
easy as one head is off. I’ll have to remove the studs that go through the
head into the cover etc, but after that I hope the cove should move
sideaways a bit away from the other head and come off easily.
Does anyone know if there are any locating dowels between the block and the
cover that would prevent it moving sideways once all the bolts are out?
Did you remove both heads? Your comment about the valve seat being pounded
to pieces makes this a very good idea. We’ve seen a lot of instances where
some of the seat pieces find their way into the opposite head. This is not
supposition; I have seen this a number of time with my own eyes.
No need to with my motor, there is no connection between the 2 manifolds as
I dont use the original AAV setup.
I set the idle with the actual butterflies and balance the 2 sides using a
set of vacuum gauges.
Been doing it this way for years on motorcycles, so no reason it should not
work with a car!!! And before anyone yells at me, I am not using the
original engine management system. Its an EMS fully programable one.
Andrew Holley
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After a busy xmas / new year period, I have finally got the head off the
XJS.
Was not anywhere near as bad as the last time when I did the other head 2
years ago.
Damage was much as I thought it would be, the exhaust valve seat on No6 Rh
side had broken up and got pounded to pieces. Does not look like any damage
to the bore and the piston should clean up ok.
Is this a problem only with the pre HE heads or are the HE’s prone to dropping
seats too?
Steven Hall
85 XJS
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !