On Fri, 17 Aug 2007 19:16:56 -0500, "Jim Burns"
wrote:

I'll take your word for it. The only piloted ones that we ever saw
were the OEM Lycoming ones.

Wonder if it (having them pressed in) helped...

Regards;

Mark

Pretty much nailed it. Minor nits, the piloted pins don't "press" in,
they slip in quite nicely until the inside of the pin gets varnished
up.

The pressed in plugs I refered to are factory pressed into the pins such as
the Superior SL13444-1. We ran across this type of pin on the last cylinder
we swapped on the Aztec. We pulled and pressed the plugs out of the old pin
just in case we needed it (we didn't, the new cylinder came with a pin) the
old plug stems were "fluted" and definately had been pressed into the pin.
The new pin confirmed the construction, it also had factory pressed in plugs
rather than caps.

From Superiors service letters:
To further improve the durability of the piston pin plug, Superior Air Parts
has now developed a new

piston pin assembly, the SL13444-1, for the 5.125 inch Textron Lycoming
cylinders. This new

assembly incorporates a heavy wall piston pin and two piloted plugs that are
press-fitted into the inside

diameter of the piston pin during manufacturing. Superior believes that the
use of the SL13444-1

piston pin assembly will provide greater engine reliability and durability
because it greatly reduces the

possibility of the plugs spinning in the piston pin.



Jim