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Re: Bending exhaust pipes

The LWB downpipes available for the last 25 years or so are a compromise between Box and Ruby type because they can then be made in greater quantities and ultimately cost (us) less.

They require a little tweaking, most times, but nothing drastic in my experience, provided the rest of the system runs the correct route. I have found all of them require trimming at the end to suit individual cars and they are least correct for RNs.

I can talk you through exactly what I do if you email your number again Mick.

Re: Bending exhaust pipes

i cant quite get my head around this one.

so they dont actually fit ANYTHING?

being a supplier of parts, i can understand trying to make one item do two jobs.

and there have been plenty of complaints on here over parts not fitting.

the bit i dont get is we are down to perhaps one or two suppliers who make exhausts.

and they still want to make one size fits all.

welcome to call me out on this one. but surely if only one or two suppliers are going to make parts, they should make them right.

if these exhausts are made in the uk, prices will not change for say 100 pipes. made in 4 different forms.

if they are coming from china, with no prospect of returns, then supplier knows the risks and gains, if something doesnt fit because china got it wrong, sell them as seconds at a reduced price. then get them done properly.

at least in the past having a number of suppliers, we had a choice. buy it cheap. and make it fit yourself. or pay more for something that fits.

a slightly annoyed tony

Location: huncote on the pig

Re: Bending exhaust pipes

I think that Tony is quite right, especially with reasonable modern CNC pipe bending equipment it should be no more difficult to make 1 correct as 100 and making 4 different types should be no problem at all.

Location: Near M1 Jtn 28

Re: Bending exhaust pipes

It is frustrating, but I have to say the supplier has been more than helpful, above and beyond what one would expect, and Ruaridh has passed on some very useful tips.

Austin Seveners never fail to disappoint and have rallied around with support and advice. I am humbled, and slightly rumpled from lying under the car for an extended period of time.

Location: Doncaster

Re: Bending exhaust pipes

I'm not taking sides here, but this is not a new problem and certainly not confined to the Austin Seven market. In my experience replacement exhaust systems from spurious manufacturers over the years,for Moderns and Classics, have been notoriously inconsistent fits. It is quite likely that the Austin Seven pipes available today have themselves been copied from dubious replacement parts, but even so the problem would be compounded by the mixing and matching of engines, crankcases, manifolds, carbs etc. which don't necessarily have the same footprint. I suspect that even if a combination of 10 or more pipes and boxes were available there would still be complaints that they did not fit properly. What is preferable, a universal system available at a reasonable price that can be tweaked to fit, or nothing at all?

Re: Bending exhaust pipes

It is quite likely that the Austin Seven pipes available today have themselves been copied from dubious replacement parts,

Hi badger,
You may be right with the above statement.

My belief is this has also happend to brake cams.


Location: Huncote on the pig

Re: Bending exhaust pipes

I have fitted quite a lot of new parts this year, they all needed fettling.

Brake cam outer circles needed turning down a little, brake levers needed filing all round to remove the burrs, brake cable caps needed quite a lot of attention....and so on.


Location: On a hill in Wiltshire

Re: Bending exhaust pipes

As a long time owner of RN saloons I used to buy SWB front pipes which fitted a standard saloon with a standard engine and pass through the hole in the front cross-member and lengthen to suit. The LWB front pipes were a mile out being made to fit the later combined manifold and pass under the front cross-member. The silencers fitted with no problems. Nobody makes a RN saloon tailpipe, so I bought a LWB tailpipe and cut it down to make two RN ones. That was a disaster because it was too small and took 20 MPH off my top speed, it was made to slide into the silencer outlet. The original RN tailpipe was part of the silencer. So I took the tailpipe into work and the pipe fitters made new tailpipes of the same shape but to fit outside the silencer outlet. When I built my last RN I took the system off one of our cars to a local stainless steel exhaust manufacturer and asked them to copy it. It fitted perfectly and cost about 20% more than one from our suppliers, that was 20 years ago. I realised that the RN being only in production for a year was a problem for our suppliers.
I did try a reliant manifold and carburettor some years ago and found that the front pipe wouldn't fit, until I adjusted it using a drain grid in the road to hold it while I heaved. That was a spare LWB MS pipe I had kicking about.

Re: Bending exhaust pipes

Gadger, I was thinking along the same lines as you when faced with two very different pipes and speculated that like 'Chinese whispers' they may have evolved as more copies were made. Mine is not a complaint as such, I can accept there will be differences, but more of a plea for outside help and advice. I have limited mechanical skill and only basic tools, probably like a lot of Austin Seven owners and particularly those new to the scene and so what might seem a simple job to those more experienced becomes quite daunting to the novice, so even though the appeal of the Seven is its simplicity, for some of us that is only acquired through lengthy ownership and a willingness to learn; 'tweaking' for some can be a massive challenge. I'm getting there, but am still highly dependant on others like yourself and am grateful the input and for the parts availability that exists today.

Location: Doncaster

Re: Bending exhaust pipes

It is curious but original road test and present owners generally indicate a performance from the RN as at least as good As RP despite lower c.r and updraught carb. Unless the low cr head breathes better, the exhaust seems to be the difference.(Quoted hp may not be the maximums.)

Can anyone advise the i.d of original RN tailpipe?
Ditto RP?
And the construction of original silencer or effective aftermarket ones?

Before anyone gets carried away with sand I can recall my father for some reason making a new front pipe that way. It involved a lot of heating of the sand to dry and repeated thorough compacting. The final heat was against firebricks with plumbers blowlamps (kero and white spirit). Welding of standard bends etc would now be far more simple, if not so pretty.

Location: Auckland, NZ

Re: Bending exhaust pipes

Just to update the forum, I got a friend of mine to cut and weld the new pipe to match the original, and weld the end back on to the original pipe I had to cut to remove from the car, which had only surface rust on examination. The replacement pipe needs some slight adjustment so the original has been used until the engine is run in. I now have another pipe that will need the same treatment and a possible place to have it bent.

Looking back over the thread I notice in my July 24 (3.51) posting I borrowed an 'i' from Ruairidh's name to use elsewhere and forgot to say - sorry Ruairidh!

Location: Doncaster