Being well into the rebuild of a 73' TR6 engine, I have come across the
most bizarre chemical reaction I think I've ever seen. Recently I was
using a typical parts cleaning solvent and extra fine emery cloth to clean
up the pistons/con rod assemblies. The combination worked great for
removing the carbon & oil sludge build up. I'm reusing the original
pistons, so I decided not to disassemble the pistons from the rods. When
all were nice a clean, I lay them out neatly until I was ready to
re-install. When I went back approx. 3 weeks later, to install the rings,
the pistons were seized tight on their pins. Apparently, the solvent which
I had allowed to air dry, had reacted with the old oil on & around the con
rod small end and wrist pin, and crystalized it. It looks almost like
dryed up & hardened pine sap in appearance. It has plugged many of the oil
ways and rendered the piston assemblies useless. I have decided to take
the assemblies to my local machine shop and have them all hot-tanked in the
hope that this will free everything up and allow me to re-lube & install
them back into the block.
Has anyone else ever heard of, or experienced this phenomenon? The solvent
was everyday parts cleaner solvent available at auto supply stores.
Is Hot-tanking the assemblies the correct course of action?
This is my first "full blown" engine rebuild, I expected surprises along
the way, but this is ridiculous.
Paul Lacroix
1973 TR6
Ottawa,Canada
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