[Healeys] Down Pipes - The Final Saga

[Mark Donaldson]

Same for me.  27 years so far on my tri-carb, and over 40 on my BN2.  
 
That said, I was told many years ago that the only reason the flex pipe
section was part of the down pipes was to facilitate easy alignment and
fitting of the muffler and tailpipes whilst on the assembly line.
 
Cheers
Mark
 
Ardmore
NZ

  _____  

From: Michael Oritt [mailto:michael.oritt at gmail.com] 
Sent: Saturday, 26 October 2019 2:12 a.m.
To: Chris Dimmock
Cc: Neil McDonald; Austin Healey
Subject: Re: [Healeys] Down Pipes - The Final Saga


I'll second that:  I have DW exhaust headers with no flex pipe in the system
and exhaust wrap that has been on for 23 years with no problems. 

Best--Michael Oritt

On Fri, Oct 25, 2019, 8:36 AM Chris Dimmock <austin.healey at gmail.com> wrote:


I have always had extractor (header) type manifolds fitted to my Healeys
since 1986. 
My BN1, and my BJ8 - No flex pipe - all solid pipe - just like my previous
Sprites. 
The extractor exhaust on my Healey 3000 - which has been wrapped since 1995
- has just recently celebrated its 24th anniversary on the Black and White
car. 
So no flex joint pipe. Mild steel - wrapped - and I'm now on my second
muffler with my side exit exhaust. 
Ok - the first one had some repairs - but all the damage and wear was road
clearance related. 
Ignore the flex pipe. I've never had one ever in 35 years!
Ignore the doomsayers who will tell you your mild steel exhaust will burn up
with exhaust  wrap. It won't. Mine didn't. 
My extractors are still fine. And I'm on my second muffler - and my ground
clearance is probably less than yours!
The only enemy is ashphalt!! 
Best
Chris
www.myaustinhealey.com 



On 25 Oct 2019, at 12:52 am, Neil McDonald <nmcd10 at gmail.com> wrote:



An exciting subject indeed!

I am about to fit an unused mild steel down pipe that I have had on the
shelf for maybe ten years. No sign of rust but I am away from home right now
so can not test it for flex. I might zap it with WD40 before fitting - can't
hurt. 

The question is - when brand new do the mild steel down pipes ever show any
sign of flex?

Neil
BN6

On Thu, Oct 24, 2019 at 2:42 PM Perry via Healeys <healeys at autox.team.net>
wrote:


Listers

As a follow up to my post on 10/18 on this exciting subject, I decided to do
an experiment with a couple downpipes I had in the parts bin. Both pipes are
new old stock and have never been on a car.  One is stainless and the other
mild steel. Both have been laying on a shelf in the garage for at least 9
years. 

The test was to measure how much deflection was noted in the flex portion of
the downpipe when the tip (where it enters the muffler) is loaded with a
weight. The upper portion of the pipe was firmly held by the bench vice. 

Should have started with something less then 10 pounds but the stainless
moved considerably under that weight.  The mild steel did not budge.

At 47 pounds I heard a creaky noise but no movement on the mild steel. I
then applied an unspecified force with my hand to the 47 pounds and no
movement. 

My conclusion is that the mild steel flex pipe, once it takes a set, ie,
Gets Rusty, does not flex. It is the weak link that will fail but it might
as well be a piece of regular pipe.

Perry

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