A while ago I asked for advice on the causes of blue smoke on decceleration
that afflicted our Mk1 Vitesse. I was advised that it was most likely due
to worn inlet valve guides or oil control rings. I was already aware of
these possibilities but had discounted the former as I had (or so I
thought) paid to have the valve guides replaced and was hoping the latter
was not the cause as I didn't really want to dismantle the engine at this
stage (compression still good). However looking at the receipt for the
work I had done on the cylinder head, I discovered that only the exhaust
valves and guides had been replaced. I have now had the inlet guides
replaced, which were very worn, but on the machinists advice retained the
old valves.
Having reassembled and fitted the head, the car was taken for a
test run, with the hope that the embarassing smoke problem had been laid to
rest. Unfortunately once the car was thoroughly warm my heart sank as the
smoke signals began to reappear, albeit not half as bad as they were
originally. I would like to know if the problem still lies with the
guides, or is the remaining smoke due to the piston rings? Is there a way
to differentiate between these two causes? "K-Line" guides were fitted, I
don't know if this is a type or a brand name. Is any one familiar with
them? If so, are they intended to be used with valve seals?- the machinist
said they would be OK without. I can't remember what the original guides
were like, but these new ones are not smooth, but rather, have equally
spaced circular grooves along their length. Has anyone tried the valve
stem oil seals listed by John Kipping?
The other problem I need some help with concerns, I think, the distributor.
I have set the dwell (using a meter) and set the timing dynamically to 10
degrees BTDC. The specs for a Mk1 Vitesse call for 13 deg., set
statically, but I read somewhere that this was for five star petrol, and
that the timing should be retarded to 7 deg. for contemporary leaded. I
decided to compromise. The problem is that occasionally when idling, the
engine temperature will get quite high, which would indicate the timing is
too retarded. Should I reset the timing back to original specifiction? How
can I tell if I advance the timing too much? - I'm not really sure what
pinking sounds like (is it unmistakable?) and have also read somewhere
that modern petrol has additives that prevent it . Does setting the timing
statically and dynamically yeild different results? Also, as the problem
is intermittent, could the advance mechanism be sticking? i.e. maybe it
has been stuck when I set the timing, but has subsequently been
intermittently settling back to a more retarded position.
Thanks in advance for any replies,
Pat Edwards.
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