Folks,
After my latest gasket blow-out, I sent an email to Moss Motors tech
support. Michael Grant was kind enough to reply. Following is the email
exchange I had with Michael regarding problems with these gaskets (or
installation). Other Listers have indicated problems similar to mine.
Michael agreed to let me forward his replies--with useful info--to the
List. Michael has also indicated interest in others' experiences, good
or bad. His email is: moss.tech@mossmotors.com
Note I have followed Norman Nock's advice and "touched up" the
downpipe flanges. It's possible I have warped manifold flanges, but
the gaskets do hold for up to 10K miles; I'm all but convinced the nuts
just have to be torqued regularly.
bs
***************************************************************
Bob Spidell San Jose, CA bspidell@comcast.net
'67 Austin-Healey 3000 '56 Austin-Healey 100M
***************************************************************
-------------- Forwarded Message: --------------
From: "Moss Motors Tech Services Dept." <moss.tech@mossmotors.com>
To: bspidell@comcast.net
Subject: 529-017_GASKET, EXHAUST FLANGE_AHY 100-6, 3000_keep blowing out_(Req.
#215139)
Date: Mon, 9 Jul 2007 15:56:08 +0000
> Bob,
>
> Thank you for the additional information.
> If this is a widespread problem, I'd like to know more.
> It would be especially helpful to hear from those that are not having a
> problem.
>
> If you feel that this exchange may be of interest to the forum, go ahead and
> post it.
>
> Best Regards,
> Michael Grant
>
> -----Original Message-----
> From: Bob Spidell [mailto:bspidell@comcast.net]
> Sent: Friday, July 06, 2007 4:30 PM
> To: Moss Motors Tech Services Dept.
> Subject: 529-017_GASKET, EXHAUST FLANGE_AHY 100-6, 3000_keep blowing
> out_(Req. #215139)
>
> Hi Michael,
>
>
> Thanks for the helpful reply.
>
> I bought the first set from Moss in '01, and they failed probably after a
> couple of years. I've tried two types of gaskets: "steel"-faced from Moss
> (the old set, I haven't received my latest Moss order yet), and
> copper-faced.
> The copper-faced set were given to me between my two Moss orders.
> I thought they might work better, but now I think there isn't much
> difference.
>
> I did flat-file the downpipe flanges before the latest installation. I
> don't think I removed too much metal, but can't rule that out. At any rate,
> the gaskets seem to work fine for anywhere from 5-10K miles, then at least
> one will blow out. I put 5K or more miles/year on my car, so maybe that's
> part of the reason I seem to experience this problem more than most (though
> others have indicated they are having similar problems).
>
> I have an older Ansa free-flow exhaust. As far as I can tell it's OK (I
> have very strong pulses at the pipe end). I think the studs are OK
> (I've tried new nuts), but I'll certainly check before I install the new set
> from Moss. I'll install the new set--keeping your advice in mind--and
> hope for the best. I'll also make a point of torquing the flange nuts
> at least once/year.
>
> I think this may be at least partly due to the insulating material in the
> gaskets (I know the hazards of asbestos, but nothing else works as good).
>
> This has almost got me considering headers ;)
>
> I'm on the Healey Autox email list; may I forward your reply to the list?
> Others have indicated problems like mine, I'm sure they would appreciate the
> tips.
>
>
> Thanks again,
> Bob
> --
> ***************************************************************
> Bob Spidell San Jose, CA bspidell@comcast.net
> '67 Austin-Healey 3000 '56 Austin-Healey 100M
> ***************************************************************
>
> -------------- Original message ----------------------
> From: "Moss Motors Tech Services Dept." <moss.tech@mossmotors.com>
> > 154341
> > BOB SPIDELL
> > 1070 KELTNER AVENUE
> > SAN JOSE, CA 95117
> > 408-554 6324
> > bspidell@comcast.net
> >
> > Re: 4-447309 529-017 04/11/01 Sale GASKET, EXHAUST
> > FLANGE WH1 -2 4.95 9.90
> > 5-1404762 529-017 07/03/07 Sale GASKET, EXHAUST
> > FLANGE WH1 -2 5.30 10.60
> >
> > Dear Bob,
> >
> > I am sorry to hear that you are going through flange gaskets.
> >
> > If I identified you correctly, you have bought these from us twice,
> > once in 2001, and once more a couple of days ago. Have you bought
> > others elsewhere between these two purchases? Or did the ones you just
> > bought blow out quickly after installation?
> >
> > What kind of exhaust system do you have on your vehicle?
> >
> > About the flanges; they Falcon stainless steel system for the
> > BN4-BJ7(not the one for the BJ8) had oversized holes for the three
> > studs. This was not an ideal situation, and although no one had ever
> > commented on this issue, we did a drawing for Falcon so they could get the
> flanges made correctly.
> > It is not relevant to your situation, unless the holes in the flanges
> > on your down pipes are oversized.
> >
> > There are a number of factors that will contribute to the problem you
> > describe.
> > Excessive back pressure (muffler or pipes collapsed or clogged)
> > The BJ8 in particular generates a powerful exhaust pulse, the bane
> > of many an aftermarket exhaust system.
> > Sealing surfaces uneven.
> > If the surface of the mating surfaces are gouged or nicked, or is
> > there is material from the gasket stuck on them, you will never get the
> > gasket to seal. The flange on the down pipe are easy to examine
> > because you can disconnect them and get them out into the light. Look for
> > the tell-tale scorch or soot marks that may tell you where the
>problem
> > area is. You can use a fine flat file to dress the surface lightly
>to
> > remove any surface imperfections. Don't get carried away.
> > The manifold is impossible to examine properly when it is in the
> > car. Best you can do is to look with a mirror and a good flashlight.
> > Again, look for clues that will locate the point of the leak. If the
> > surface needs to be dressed, the manifolds need to come out.
> > Damaged Studs or nuts.
> > You tighten everything up, but the flanges are not really clamped
> > together because the nuts are jammed up on a couple of bad
> threads.
> > Replace the studs and nuts.
> >
> > There are undoubtedly things I have not thought of, but I think these
> > are the obvious ones...
> >
> > Best Regards,
> >
> > Michael Grant
> > 61 MGA, 73 MGB GT, 67 Austin Healey
> > Product Manager
> > Moss Motors, Ltd.
> > 400 Rutherford Street
> > Goleta, CA 93117
> > 805-679-7234 (Direct Line)
> > grantm@mossmotors.com
> >
> > Please use the REPLY function when responding to an email received from
> me.
> > Moss Motors, Ltd. is not liable for injury or damage due to incorrect
> > installation or use of their products. All products are sold with the
> > understanding that the safe and proper installation and use of the
> > products is the customer's responsibility. This Email and any files
> > transmitted with it are confidential and intended solely for the use
> > of the individual or entity to whom they are addressed.
> >
> > -----Original Message-----
> > From: bspidell@comcast.net [mailto:bspidell@comcast.net]
> > Sent: Monday, July 02, 2007 2:22 PM
> > To: moss.tech@mossmotors.com
> > Subject: 529-017_GASKET, EXHAUST FLANGE_AHY 100-6, 3000_keep blowing
> > out_(Req. #215139)
> >
> > Submitted Via: MossUSA
> > Name: Bob Spidell
> > Email: bspidell@comcast.net
> > Phone: 408-554-6324
> > Best Time to Contact: Anytime
> > Order Number:
> > Part Number:
> > Make: Austin-Healey
> > Model: 3000 (BJ8)
> > Year: 1967
> > Comments: I am having problems with exhaust flange gaskets blowing
> > out. I see in your catalog that you've contacted the manufacturer
> > with specs for NOS downpipes; do you have a new downpipe in stock that
> > would fix this type of problem?
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