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Yair G'Day Dave,
END PIECES
The easy way is to glue the end pieces on with
superglue. All late model Madza seals are supplied pre-glued. Trouble
is, if you have to dissassemb;le the engine, they need to be
re-glued. I've been doing this for 25 years now. All you need is
just a TINY drop. Lay a piece of "Gladwrap"
down on a FLAT surface, lightly oil your fingers and wipe gently with
a rag (so the superglue doesn't stick to them), and make sure the mating
surfaces of the apex end piece and the apex seal itself is clinically clean (I
use carby-clean, but nail polish remover, MEK, or acetone does
the job equally as well). I normally give them a light scuff with some 800
wet&dry as well.
Put a SMALL drop of the superglue on the end of the
apex seal, lay it down on the "Gladwrap", and then lay the end piece
down and push together. Make sure that the sides are in the one plane
(otherwise, you won't get the endpiece past the corner
seal). Voila! C'est magnifique!
You then avoid this silly business of putting
the end pieces in first (almost guaranteed to cause a problem as you can't see
what you are doing). Trim off any overflow of the superglue, and
then fit the seal trouble free. (As long as you made the superglue bond
correctly! Otherwise they become "devil" pieces - where the devil did that go!
REAL "fun" at 2:30 am on a Sunday morning when you have to be at scrutineering
at 7:30 am - NOT!!!).
One other trick is to make sure that the end piece
is SLIGHTLY up the diagonal. The "pointy" end of the end piece needs to be
SLIGHTLY proud of the top of the apex seal. As the motor is
torqued, the end plate will push the end piece down the diagonal and will
break the superglue bond - you can distinctly hear the clicks as the
superglue lets go. (If you don't get it right, you will have
compression problems until the superglue bond breaks with the heat. (Go figure
how I know!! (}:>)
SIDE SEAL FAIURE
As for your compression problems, I reckon
that you had a side seal SPRING collapse. They tend to wear on the
bends. They don't have to wear much to seriuously compromise their
strength. Get one of the old ones and try bending it. Most probably
it will bend easily, and probably break. Once the spring
fails, the side seal itself is not properly supported, and will in
the fullness of time, do what yours did - break!
SEAL DURABILITY
As for the durability of the side seals
themselves, I've over the past 30 odd years, I've re-used second hand ones
over & over in cheap rebuilds several times, as long as they come up
to thickness and depth and length specs. But I ALWAYS, ALWAYS,
ALWAYS replace the corner seal and side seal SPRINGS - EVERY rebuild,
as well as ALWAYS fitting NEW corner seals. 90% of comprtession problems
in rotaries comes from the corner seal clearances. If the new seal
is a little too tight, you can usually make it fit by linishing off the
top edges a little with some Wet&Dry (320 is about the right grade).
On second hand rotors, the corner seal hole ends up slightly oval,
so a slightly bigger seal will fit if you reduce down the ends where the apex
seal goes.
The corner seal should NOT fall out when you turn
the rotor over. If it does, it's too loose!!! They should be a nice
sliding fit with just enough resistance to NOT fall out when upside down.
If you measure each corner seal diameter, you will find a variation.
Careful selection and fit will ensure perfect compression. Buy an extra packet
of them to make sure you get the sizes right.
They are cheap, good insurance, and it
is just common sense that the side seal springs, being so
fine, (especially the REW ones) are pretty delicate little
things. BTW, always use the latest corner seal springs too.
The twisted sheet ones (out of the REW and Renesis engines), not the wire
ones. They are much more resistant to heat stress.
Enjoy,
Leon
----- Original Message -----
Sent: Wednesday, October 12, 2005 6:16
AM
Subject: [FlyRotary] Help!! Installing
Tracy's apex seals
In Bruce's video he talks about putting the corner piece of the apex seal
toward the front of the engine. But with Tracy's seals the corner piece
is not attached. So I cannot get the apex seal spring to slide in because the
corner piece (now down at the bottom of the slot) has slid back a little.
If I put the corner piece toward the rear of the engine, I am able to get
everything in place just fine.
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