Hi, listers
I'm more than casually interested at the comments I've seen over the last
few months on this list and the Spridgets
one as well, about people's concerns regarding likely engine life when
undertaking a full rebuild.
For some reason, many people seem to feel (rightly or wrongly) that they
probably can't hope for much more than
60k miles out of a rebuilt unit. At least, that's the impression I get.
Isn't this rather low?
What I feel many people may be overlooking is the fact that modern
lubricants, be they mineral or synthetic, are one
quantum heap better than even 10 years ago. Added to that, operating
pressures and temperatures in the engines of
the sixties and seventies are lower than modern units. This has already
been recently discussed.
Surely, longevity of power units and drivelines depends rather more on the
way they are used rather than the distance
which is travelled. It's well known that short journeys cause more damage
than longer ones because the engine is probably only operating at normal
temperature for a brief period before it has to cool off and the wear
process starts over again the next time it is started.
Last weekend, I was talking to a man at BMIHT who had a 1957 Standard
(Triumph) Ten which he claimed had covered 170,000 miles on the original
unit without a rebuild and only three decokes. It's still on the original
clutch - though it'll be having a new one during the rebuild!!!!!!!!!! His
father had bought the car new and had maintained scrupulous records of its
maintenance. The old man is now long dead and his widow had been using the
car before surrendering her licence on age grounds. The visitor told me he
had decided to take out the engine and gearbox for a complete overhaul.
Apart from the box needing some new synchros, the block only needed minimal
boring but they took it to + 10 thou and the crank needed no attention at
all. As this engine was effectively the Spitfire engine of whatever size
you want to talk about, I think this minimal overbore speaks for itself.
This isn't at all unusual in my experience and I've seen many BMC and
Triumph engines over the years that have gone well past 100,000 without any
problems or excessive oil consumption.
On top of that, two fitters I have got to know in the Centre workshop, tell
me that whenever they strip an engine of a pre-war car, they tend to take
some detailed measurements of bore wear. More often than not, it is
virtually nil and we are dealing with steels of arguably much inferior
quality than today.
My own view is that any LBC engine which is allowed to run for prolonged
periods, without being unduly stressed or 'red-lined,' has its oil and
filter changed regularly and is properly cared for during winter lay-ups
should do at least 75000 miles without any problem at all - and might well
do far more than that. I'm expecting my own cars to hit six figures on the
odometer before any attempt is made to pull them down for a rebuild.
John Macartney
Besotted with Triumphs...
... but sadly driving Japcrap
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