An offering from Paul Richardson on engine overheating. Not something I had
given much thought to..... that a small amount of contamination would have
such an effect. Thanks Paul....
(Paul perhaps you have not done this yet, but <fot@autox.team.net> in your
address book will give you the entire list of the "Friends of Triumph".
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From: Paul Richardson[SMTP:Paul-Richardson@cyberware.co.uk]
Sent: Thursday, July 09, 1998 12:01 AM
To: AlexanderJosephH@Waterloo.deere.com
Dear Joe
While I'm switched on, I've noticed several enthusiasts in 'Friends of
Triumph group' who are experiencing overheating engines. One of the most
regular and generally undetected problems with persistantly overheating
engines can crop up after a rebuild, or slowly develop over a long period
of time because of a lack of cleanliness inside the water jacket. I.E. if
traces of machine oil etc are not completely purged from the system or oil
ingress from a blown gasket etc, overheating can and will result.The oil
will coat the water jacket walls and restrict the heat transfer to the
coolant.
The best example of this was with the Rolls Royce Merlin engine that
powered our Spitfires during the war. The problem was traced by Rolls
engineers to only small amounts of machine oil in the waterways left over
from the manufacturing process of the engine blocks and heads. It was found
that only 'half a percent' of oil in the water system caused serious
overheating. This problem only showed itself when the Merlin X11 engine
was converted from a 100'% 'glycol' system to one of pressurised water with
a 30% glycol mix as anti freeze. I.E. The 100% glycol coolant served to
dissolve oil deposits on the water jacket walls.
I've also experienced this with racing engines after an engine blow. The
waterways in the engine block etc. must be purged completely clean with a
suitable solvent after any rebuild as a form of insurance. When rebuilding
a TR engine, or any classic car engine, purging the water system is a must
because, we don't know if the system has ever been thoroughly cleaned by
previous owners .
See you on the 15th
All the best
Paul
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