Author: TinyHost@aol.com at INTERNET
Wrote about:
>Third, is a stainless-steel exhaust worth putting on it? I've been told
>that some stainless-steel may not mate well with mild steel, and may
>cause significant corrosion. (To the mild steel, I presume.)
I think that stainless systems are well worth it if you expect to keep
the car a few years and want to pass on a well sorted classic to the
next owner. These systems are not all created equal however. Fit a
system that is known to fit the TR6 well, is known to be durable, and
that sounds good. The following is based on my experience importing a
system for my Rover 3 litre, hopefully it will be of some help:
In the UK there are at least half a dozen suppliers of stainless
systems of varying quality and cost. (You do not necessarily get what
you pay for.) The tube walls should be at least 18 gauge, and mandrel
bending gives smoother bends without reducing the cross section of the
tube at the bend. (I've forgotten what the other type of bending is
called.) Make sure the mounting points and connections between
sections are correct for the car.
(A non-TR aside: some systems originally had cast-steel three-hole
flanges connecting the sections. Stainless systems are available with
these flanges, but the flanges themselves are always mild steel, no
matter what the sales person may tell you.)
The most popular (and supposedly the most "stainless") material used
for the tubing is 304 stainless. There is at least one other common
type (a 400-series I think) which will eventually rust, but may be
able to withstand vibration better. I have heard of this second type
sometimes being used for the first pipe in the system where vibration
is more of a problem, and corrosion is less of a problem. Make sure
the welding is done well too.
The sound: the system will last a long time (forever?), so get one
that sounds good. Stainless steel has different acoustic properties
than mild steel, so this is important. Also, you can not see inside
the mufflers, so you can't tell if any construction short cuts were
taken. My Rover sounded like a tractor at first with the s.s. system,
and I was rather disappointed to say the least! It is definitely
improving with more miles on the car - the coating of exhaust crud on
the inside apparently quiets things down.
One s.s. system vendor advised that s.s. systems tend to be noisier if
the mixture is not quite right. In fact the Rover sounds much better
after it warms up and the mixture is leaner. (I don't know how much
the temperature of exhaust system has to do with it.)
In short, buy a system that has worked out well on another car just
like yours. Finally, I have not heard of the problem with the
stainless and mild steels conflicting with each other. Generally the
stainless will be separated from the iron manifold by a gasket and
from the rest of the car by rubber hangers, so this should not be an
issue.
|