Subject: [FlyRotary] Re: V shape Apex Seal Slots?


> In a message dated 04/15/2005 1:44:52 AM Central Daylight Time,
> lendich@optusnet.com.au writes:
>
> << On Thu, 14 Apr 2005 16:26:19 -0500, Russell Duffy wrote:
>  > > Apex Location Base Top
>  > >
>  > >
>  > > Seal1 1.99mm 2.16 - 2.26mm Seal2
>  > > 1.98mm 2.22 - 2.25mm Seal3
>  > > 1.98mm 2.18 - 2.20mm Clearly the slot is larger at
>  > > the top - is this due to design or is this due to wear? Lynn??? >>
>
>
> The slot is perfectly straight. No taper at all. If you stand a new or
near
> new apex seal on end in the slot, the exposed end should not move more
than
> (about) 3/16" total. New slot and new seal gives nearly no movement. The
3/16"
> would be end of life span.
>
> For aircraft use, new or nearly new is the way to go.
>
> You can take engines apart that have been running fine, and the apex seals
> are just about to fall out of the slots they are so short. The slots can
wear
> into obvious "V" shapes, and the engine is still running fine. My wife's
RX-3
> did that. I was just sitting at a stop sign one day and whack!!  A seal
came out
> of what was left of a big "V" slot and the rotor crushed it against the
> housing. There was no chrome left on the rotor housings. Big grooves in
the irons.
> The only piece I could use was the crank.
> The whole thing was scrap.
>
> The rotors are made of cast steel. You can weld on them. I have TIGed
holes
> shut and built up gouges and smoothed them off. Again not for aircraft but
for
> a dune buggy or any non critical application, I see no reason for
scrapping a
> piece I can fix quickly.
>
> I grew up during W.W.II and you were literally not allowed to throw
anything
> away. So I don't (until recently).
>
> Lynn E. Hanover
>
 Thanks for the download on apex seal slots, Lynn.  I couldn't imagine them
not being vertical - but, was amazed at how much they had diverged at the
top - so thought I would ask from an experience source.  Of course the
rotors were only in my aircraft engine for 150 hours but who knows how long
or under what conditions they ran before.

I'll try the apex seal on end test and see how much wiggle I get.

Ed A