--------------------------------------------------------------------------
Your following message has been delivered to the 138 members of
the list
murphy-rebel@dcsol.com at 16:41:15 on 19 Nov 1999.
--------------------------------------------------------------------------
Bill (and all), I could do the "well of course my way is the best" but that
is not the way I operate! Depending on how puckered your firewall is, you
may have to force things back in place before you fix.(a heavy duty
turnbuckle has been used before to expand the distance) Murphy's fix is to
put a piece of channel(.032 ST28 I believe) across between the two upper
mounts and you must do a long length on one side and a short overlapped
length on the other to clear the witches hat and as far as I know removal of
the mount bolts is not required. If you have no electrical wires, control
push pulls or tach cables in this area it may be the easier route, although
I question the fact that it doesn't actually go under the mount bolts(as far
as I know) This leaves a small area that could still compress. My plates
require the unbolting of the engine mount from the firewall. The top ones
can be done one at a time if you don't have access to a hoist or block and
tackle to hold the engine up. With your O-290 being a Conical mount (it is
isn't it) you already have a tube going between the lower mount bolts so the
lower plate isn't absolutely necessary and it is very hard to install with
the engine already in place. (The dynafocal mount has no cross tube
here.)You would however have to put one penny washer under each lower mount
flange to bring it out even with the new .063 top plates to keep the proper
thrust line. I have no problem telling people how to make the triangular top
plates, etc. as I only charge $100cdn for them and if you don't buy aluminum
in full sheets, you will pretty well pay this for the small amount that you
need! If you have access to some .063 6061-T6 you can make your own as
follows.(do them in poster cardboard first!)The top plates are made to fit
from the top corner at the witches hat, hugging the the curve and slant of
the firewalls outer edge down about 8 1/2" and then straight across to the
witches hat again. The lower edge going across has a 1/2" brake in it to add
rigidity.(don't have a brake use some .063 angle and 1" rivet spacing) The
plate overlaps up onto the witches hat(w.h.) so you can use the same holes
and rivets to attach it and sandwich it together with the firewall and w.h.
Also rivet spacing at about 1 1/4" in rows on plate and 1" around outer edge
of firewall to securely attach. Also need to drill a hole out to match mount
bolt location in the plate and then, deburr, chromate and rivet with what
ever rivets you used in your firewall. Then re-install your mount bolt, with
one less washer that before. 2 years of pounding on Customers Amphib now and
it still looks like new! If you wanted to do a lower plate it is the same
idea except it is one plate all the way across bottom. Lower plate has what
looks like 2 mountain peaks at each end that follow up the w.h. to a height
of about 7" from the lower firewall lip and then come back down at the same
angle to blend straight across approx. 4" up from lower lip. Same 11/4"
rivet spacing throughout plate and use the existing holes in witches hats as
you do with the top plates.
I noticed in an original promo shot of the Elite that the motor mount
"beefing" plates where very local and did not tie into the w.h. Anyone that
is building an Elite would be well advised to expand these plates to pick up
the w.h. for the added strength.(as you know, people are finding out it
would have been easier to do while building it)
Another spot to add a little strength is on the top motor mount "bath tub"
fittings. On the .032 doubler that is under each upper mount fitting(or on
the outside if you did it by the manual and didn't hide it), drill out the
lower edge rivets, along with one rivet in the witches hat on the side panel
that is directly in line with the rivets you just drilled out. Cut a piece
of wing stringer (or bend one up to similar shape) to fit from the firewall
to overlapping the side panels witches hat. Mark a center line on the
stringer piece and back drill through the existing holes in the doubler and
the one in the witches hat, plus one or two new ones in between. Rivet
stringer in place (after D.B. and Chromate).
I presume you already have "my" double row of rivets up the door post!!??
Centered between each existing rivet, you should have another one staggered
forward about 3/16ths of an inch and make the top one a well
dipped(chromate) 3/16 S.S. one! How about the extra bulkhead in the floor,
centered between the rear landing gear fitting bulkhead and the next
bulkhead forward, ST28 door sills and a sandwiched extra skin below the door
sill? This ones a "while you build only!"
Sorry it's so long, no wonder I can't seem to get those NOS parts
inventoried, but I hope I helped you (and others), Wayne
-----Original Message-----
From:
BILNEWKIRK@aol.com <
BILNEWKIRK@aol.com>
To:
murphy-rebel@dcsol.com <
murphy-rebel@dcsol.com>
Date: Friday, November 19, 1999 2:48 PM
Subject: Re: FIREWALL WARPING
WAYNE:
I READ YOUR NOTE ABOUT THE FIREWALL REPAIR. WHICH ONE WOULD BE BEST FOR MY
ALREADY FLYING 0-290?
BILL NEWKIRK
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*
-----------------------------------------------------------------
List archives located at:
https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe:
rebel-builders-unsubscribe@dcsol.com
List administrator:
mike.davis@dcsol.com
-----------------------------------------------------------------