Nolan Penny wrote:
Folks, I'm not arguing that the valve lash given in the various
manuals
for Spitfires is for cold. That wasn't the question. The question
was
"When is it best to set valve clearance, hot or cold?" The answer to
that question is hot.
Well, let's put the 'various manuals' to one side and concentrate on
the factory manual as printed by Standard-Triumph.
The clearances were .010 or .012 according to model, inlet or exhaust.
In parentheses alongside is the word 'cold.'
This pre-assumes the engine is as manufactured - or to coin a term,
"stock."
For the record, at the conclusion of engine assembly and before
mounting on both the pre-run and main run dynomometers, valve
clearances were set on a cold and static engine.
It is worth mentioning that Standard-Triumph engines were designed to
run
with 'tappety' valvegear - a fact commented on adversely in many press
roadtests. The only downside to all this is that over a period of
time, say 75,000 miles, an indentation would get hammered
into the mating face on the rocker wich would give an excessive
clearance. As the engine (and car) was never expected to last more
than seven to ten years at te most - though many have now gone for
forty or more
years, I suppose it could be argued tat hot or cold, noisy or quiet
doesn't really matter too much? Hmmm.
As Michael Porter pointed out, there are a lot of people on this list
who through no fault of their own may not be too technically aware.
With that in mind, it is far safer for te novice or competent amateur
to maintain a Standard-Triumph engine in line with the dimensions
given by the people who designed and made it in the first place.
As individual competences and understandings improve over time, the
'rocket science' can then be introduced.
Jonmac
Moreton in Marsh, UK
1950 Ferguson TED20 152318 - Grey/Grey
1970 Triumph 2.5PI MG4305DL(O) - Sienna/Tan
1974 Triumph 2000 ML2294DLO - Mallard/Black
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