Jeff Chrysler wrote:

Hi Mark,

It is best if you send the o-rings back to be reworked. Silicone

glue

is not

very strong without the support of a Teflon jacket to hold it

together.

The rings will be cut down and made to an 11.155" ID so that the

ring

OD

will be close to or snug with the outside groove diameter of 11.340.

If you wish the rings to be snug to the groove ID they can be cut

down

to

11.110" ID but this probably is not as ideal due to pressure

traveling

outward.

Awaiting your answer.

Best regards,

Jeff Chrysler

There is your answer Mark. Jeff Chrysler of Creavey is our buddy :)

Paul Lamar

OK, I think I have a handle on this o-ring dimension/sizing problem now.

I

backed up and approached the sizing from a different direction.  What I

did

was to take a 3/32" x 36" piece of aluminum filler rod and shape it

to fit

the

outer water groove.  While holding it in the groove, I cut it off so

that

the

two ends just barely touched.  Then I straightened it out and

measured the

length.  This came to 35.625", the circumference.  So, 35.625/3.1416 =

11.340,

the centerline diameter.  (This dimension was referenced in a future

posting

and is what I gave Creavey when ordering.)  The mistake came from giving
11.340 as the ID, rather than the CL.  By using 11.340 ID, the

circumference

ended up at 36", 3/8" too large.  Mystery solved.  I'll call Creavy and

see

what can be done to get them resized.

Thanks for everyone's help,
Mark S.

-Jeff Chrysler wrote:

Hello Sirs,

After further discussion with Mark and using 11.34 as a groove centerline
instead of an OD measurement as mentioned earlier, I believe a seal ID of
11.240 will do the job. It is best to describe all 3 seals in terms of ID
measurement for ease of future reference.

Also- if you wish to obtain a quick and permanent stretch, try heating the
o-ring in boiling water, with a heat gun, or in a 400F or lower oven. The
heat only needs to be applied for 10-20 seconds and from there it can be
placed on the plywood form mentioned by Paul below. The stretched o-ring
will be ready in minutes.

Happy building,

Jeff Chrysler

Paul/Jeff,

I received the re-sized outer coolant o-rings yesterday and they fit
perfect.  The tag shows a dimension of 11.230 ID.  I think there are a few
on the list that were waiting to hear the final word on this
dimension.  So, the final dimension is .093 x 11.230 ID fits for the outer

coolant o-ring.  This dimension forces the o-ring to the outer wall of the
groove, so they could be a tiny bit smaller, but no larger.

Jeff Chrysler of Creavey Seal deserves a big attaboy for all his help and
understanding.  I can't say enough good things about him and Creavey
Seal.  Thanks Jeff for all your help.

Thanks,
Mark

      Paul,Mark,

        Considering all above what is the correct ID of the inner coolent
    O-ring to order? The previous posts refers only to centerline diameter
    as I recall. Mark how was the fit of your inner coolent O-ring to the
    groove? Snug to inner or outer side?

          Kelly Troyer

The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.