[alfa] Re: alfa-digest V10 #71, flexible exhaust tubing

["George Schweikle" <schweikg@xxxxxxxxxxxxx>]

Stefano and Biba,

I use flexible tubing to connect a custom header to 2 1/4 exaust tubing, and
use a band clamp similar to those used on 18 wheeler exhaust systems. This
is a 3 inch wide stainless steel band with a clamp system that is tightened
to 75 ft/lb. It can be used on flex tubing fitting over another pipe or to
connect two equal size pipes. The tightening force actually distorts the
band over the joint, and makes a tight seal. These used to be available at
J.C. Whitney, but now seem only available at high performance outlets (Jegs,
Racer Wholesale, etc). The greatest benefit is when used to joint two same
size pipes. There is no overlap required, and disassembly is easy. Look up
at the exhaust of a big truck the next time you're stuck in traffic, and you
will see such clamps. I used to use these to connect the rear muffler joint
on our Milanos. Cost is around $8.00 each.

Also, stainless steel flex pipe and the braided flexible couplings are
available from J. C. Whitney. A great source of parts if you shop carefully
and stay away from the chrome plated mudflaps and neon underbody lighting
kits.

George Schweikle
Lexington, KY

> Date: Wed, 5 May 2004 09:40:12 -0700
> From: Stefano.Iachella@domain.elided
> Subject: [alfa] re: Shankle Headers - Flexible Exhaust Tubing
>
> >I have read on the Digest about many of the two piece headers cracking at
> >certain points. I have had the European 2 piece cast iron headers on my
car
> >for many years without any cracking even though I had a lot of scraping
of
> >the catalytic converter due to low ground clearance. I thought I saw a
> >reference (that I can't find right now) that the Kartalamakis book
mentions
> >flexible exhaust tubing. I thought that might be a good idea between the
> >catalytic converter and the down pipe. Does anyone have any experience
with
> >this?
>
> I have quite a bit of experience with this. I went from the one piece
> manifold on my Alfetta to the Shankle two piece header and they started
> cracking. I kept welding them and they kept cracking. They also gave me
> no low end torque so I was unhappy with them. I then got the Euro two
> piece ones and had them drilled for the air pump rail. They cracked once
> at the stud, but after a cast iron welding job, they stopped cracking.
> However, other parts of the exhaust kept cracking. My exhaust guy would
> re-weld and try to reposition things and use different hangers. He also
> insisted that the Alfetta had a weird vibration that was causing the
> cracking. My Alfa mechanic insisted that some Alfettas vibrate more than
> others, and mine was normal. Drive shaft was also fine.
>
> I eventually found the diagram in Kartalamakis' book and showed it to
> my exhaust guy (who is from Crete and says the author is also from
> Crete). He said they make those joints for Hondas. He got one for me and
> it has not cracked since.
>
> This flexible joint is not the one that looks like braided steel. Rather
> it is a spherical mating surface to allow twisting and flexing. It looks
> like a flange with spring loaded bolts. I'm hoping this has solved my
> problems, and I think it has.
>
> One thing to note about the Shankle headers too, is that they may not
> have the mounting point to the back of the engine/bell housing. There is
> a rubber mini-donut mounting thing with a bracket. This is very near
> the point where the two down pipes become one. Or very near the cat. Make
> sure the exhaust shop fabricates the mounting bracket if it is not
present.
>
>
> Stefano
> Oakland, CA
>
>
> Date: Wed, 05 May 2004 12:30:11 -0700
> From: alfacybersite <acs@domain.elided>
> Subject: [alfa] Shankle Headers - Flexible Exhaust Tubing
>
> Kartalamakis suggests a coupling behind the expansion chamber to prevent
> cracking of the exhaust pipe - as opposed to the exhaust manifold,
> though I would imagine it would help prevent cracking of the manifold
> also.
>
> In the case of the '79 exhaust, it appears as if the two flanges from
> down pipes to catalytic converter could be converted. Welding would be
> required and not sure if one is supposed to weld next to a converter.
>
> Since Leslie used the term "flexible" has anyone converted their down
> pipes to actual flexible pipe as used on older British cars and, in a
> slightly larger size, on 18 wheeler type trucks?
>
> Having had some experience with the flex pipe, it won't last as long as
> solid steel pipe, but also might allow one to move their exhaust system
> slightly upward to give more clearance - though not sure if that is a
> good idea with the catalytic converter.
>
> Kartalamakis also suggests using only U-clamps to connect exhaust
> sections together since it will allow some flex. I was going to order a
> more sophisticated and solid looking sleeve type clamp for a new
> Round-Tail exhaust since they now come in three pieces. Glad you "made"
> me look up the coupling.
>
> Biba
> Irwindale, CA USA
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