Paul,

A point well taken.

I found a seal engineering and manufacturing company in here in Denver,

CO,

that has spec'd out a design/ material for a seal they can manufacture

that

will be suitable, they say, for the the bell-housing seal.

The seal material they have quoted is  Fluoroelastomer Turcon T-40 based

on

the following parameters:

RPM:  6000 Typical
Temperature:  200-275 F
Pressure:  7-15 psi, (with .040 in and the fitting size (1/4"?) out)
  ( I told them that under cold start-up conditions, the oil will

thicken and

pressure will go up.  However they said that they didn't think the seal

would

see any significant pressure rise.)

Media:  Motor oil
Seal case material:  304 SS

Has anyone tried the above material, and if so with what success?

Their quoted price for set-up/fab is $84.23 each plus shipping.  A bit

steep,

but if it does the trick it should be worth it.

Minimum qty is four.  So there will be some left over from what I will

need.

If you think it is viable, I can place the order and the ACRE group is
welcome to the balance, at cost plus shipping.

Also, has there been any reported leakage from the seal at the prop hub?

And

if so, is this seal the same size as the bell housing seal?

Joe Graham

Hi Joe,

    I can not speak about the seal material, however, I and a friend also
order a "special made" seal to eliminate the irritating oil leak around the
rear shaft seal.  After waiting for six weeks for it, I installed it and
flew.  My experience was that the seal was worse than the $12.95 national
seal.  It was suppose to hold against 300 psi oil pressure, was well within
the fpm surface speed and temperature parameters.  On examination, it looks
as if a Teflon like material actually revolved inside a rubber like matrix.
My guess is that it needed oil pressure against the rubber matrix to force
it against the Teflon disk in order to seal.  So it might  have held against
150 psi of oil pressure, but there may not have been enough pressure in the
Ross to cause it to seal.

   So I don't won't to discourage you, but that was my experience.  Another
seal may well do the trick.

Ed Anderson

 
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