[TR] TR3A Leak down test-final findings

Alex ambritts at bellsouth.net
Sat Dec 24 14:35:07 MST 2011


Well, found out the problem at least with the number 3 cylinder in my 59
TR3A.

After establishing with the leak down test that we had a constant air stream
exiting the engine vent tube, we pulled the head again, dropped the pan and
pulled out #3 piston.

The 2 piston channels where the rings seat were cracked and broken along with
the ring (s). Everything was riding in its' place without any apparent
damage.

The sleeve wall had a few very minor scratches that the hone will easily
remove. The piston is not 86mm as I earlier reported but 87mm with 3 rings. It
is stamped RENZ 140pd in the hollow of the piston. A Google search did not
turn up anything for this piston.

So now a search for 1 piston with rings. There are many sets listed in the
Moss catalog but then again even with the sets there does not appear to be
87mm 3 ring pistons.

Anyone know if putting in an 87mm 4 ring would harm anything? Would appear
not.........not sure about balance issues..............or anything else.

So the main mystery is solved. Interesting point is how the smoking was almost
eliminated with the last few drives just before I pulling the head.

Now onto the carburetors and the condensation issues after the engine is put
back together.

Good time to replace the skinny roadside repair fan belt that was installed
last year with a breakdown. :o)

Wishing everyone a very Merry Christmas, Happy Hanukah and Happy New Years.
Alex Manzo
59 TR3A

Moss does not show a standard 87mm piston available


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