Practically Classics Forum

Wit MOT gtime coming up and my already loud system getting louder I thought I'd better have a look, so it was up on the ramps and sure enough it was blowing from where the manifold meets the pipe....but although the pipes look as good as new despite being on the car for twenty years (someone paid 430 notes for the system and sports manifold ...the bill came with the car), the mild steel clamps had corroded virtually to nothing allowing the joints to move, just look at the state of them!It just goes to show, stainless isn't just fit'n'forget

Cor! They look like they've been underwater for the last 20 years

Yep, spot on.

If you wanted to get something to rust faster, a good way would be to heat it up and spray water on it - ideally with salt in it. This is exactly the conditions these things live in, especially in winter, so no wonder really.

Stainless exhaust on my Volvo and Jag, but the clamps quickly get in an appalling state, any work you do on the exhaust you're never going to get them apart, always have to cut off and replace, which I have done on the Volvo.

I do wish they'd make stainless clamps too!

A quick search came up with these:

http://www.merlinmotorsport.co.uk/EXHAU ... index.html

I don't like the "U-bolt clamp" as they kink the pipes and can make them hard to get apart again. Older Fergy and Massey Ferguson tractors used a flat "strip" clamp which was much better. Mind you, I hardly ever tightened them up as it made it much easier to take the exhaust off to get into low buildings. I doubt that's a problem with a car though!

As an aside, a mechanic friend used to say stainless exhausts weren't too good - he reckoned that they would fill with soot (as the mild steel ones do) and performance would go down. I suspect that the muck doesn't stick to stainless systems in the same way. The other side effect though - the stainless exhaust is louder, a mild steel one fills with muck and gets quieter. I had the back box changed on the Passat at 150K miles (or so) and, when I set off home, I thought I'd left the tailgate open - it was so noisy. Six months later, it was bearable again!

Perhaps it's the one big advantage of diesels - the Golf's exhaust is original and, at 93K miles and nearly nine years, shows no signs of needing replacement in the near future!

tractorman wrote:A quick search came up with these:

http://www.merlinmotorsport.co.uk/EXHAU ... index.html

Good call, however the exhaust joint on Volvos (and Saabs) of this era are a ball-and-socket type, with a ridged clamp that goes around the outside, so these wouldn't work. I don't like the design as it's not very strong but you're stuck with it really.

Those'd fit the Jag though, I'll bear that in mind if I ever have to disturb the exhaust system.

Cheers

tractorman wrote:A quick search came up with these:

http://www.merlinmotorsport.co.uk/EXHAU ... index.html

I "discovered" them when doing the Heralds exhaust about 18 months ago. Definitely a worthwhile alternative as they can gain a bit of clearance if things are tight too.

To make things worse, a lot of what is sold as 'Stainless' isn't.

A large and well knownTriumph specialist sells Stainless exhaust systems which rust. What's more other supplier buy these and pass them off as their own. Beware.

m.thaddeus wrote:To make things worse, a lot of what is sold as 'Stainless' isn't.

A large and well knownTriumph specialist sells Stainless exhaust systems which rust. What's more other supplier buy these and pass them off as their own. Beware.

Please name and shame Rimmers here as I'm on my third from them and they'll do almost anything to wriggle out of replacing under warranty.
The wraps are stainless but the end plates, pipes and baffles are most definitely not.

Stainless system number one: came on the Dolomite so warranted to the original owner, nothing I could do about that and didn't knmow how long since he'd fitted it so nothing I could do when the front endplate in the silencer rusted out. Bought the replacement which put it into my name at least, second one had rusted through at the other end within a year and about 20,000 miles so one of their counter staff asked me to prep it for collection by their courier which I did. Waited a further few Months (fortunately, I'd bought a n/o/s mild steel one to run on) and called again to be told that their manufacturer hadn't received the exhaust back from the courier but then one of their other staff told me the truth which was that the system had mistakenly been left with them and not with the maker.
Intervention by a lawyer later and I had a replacement which although not rusty, didn't fit as well. That was in October, today I just had to fit my temporary mild steel one again as the ferritic "stainless" one from Rimmers has rusted through already and after only another 20,000 miles on the car. I'm not sending this one back until Trading Standards' own metallurgist has been and prepared their report but it doesn't take a genius to see that a magnet is attracted to the endplates and the pipes.

Clamps? I use M10 rather than M8 ones as they'll clamp tightly enough to prevent the system falling apart in use (it may well be rubbish quality but by 'eck its walls are thick!) but there's been some talk of those flat ones on the TDC board recently and I would have those on once I eventually get a stainless steel system that's made from stainless steel, which could take some time and a visit to Fin in Lincoln. I'll have to instruct him to remove the Rimmer system carefully as I don't want there to be sharp edges on any of it when I hit the useless counter droid along his useless head with the end of the thing.

I can't help thinking that using mild steel bolts on those stainless bands is just going to relocate the point of corrosion to an even smaller, more annoying part; why not make those stainless too?

IIRC stainless nuts and bolts tend to shake loose - some metallurgist will probably put me right, but I think stainless is "smoother" than mild or galvanised stuff - part of the reason why it is stainless!

It's strange that a "reputable" firm has missed out one word on it's item description: "part". Perhaps a Part Stainless exhaust wouldn't sell so well?