Vintage Six exhaust system

[galfredus]

Dear All,

I need to get an exhaust for my '29 Six (Aceca).  Can anyone advise on how to go about this?  I've been told that the system for a Triumph Spitfire is suitable.  The engine is running on triple SUs but is otherwise original.

Many thanks,

Geoffrey

[Jam2]

Depending on where you are, this guy is excellent at one off systems.
Dave Tyler t/as Len Hartley Developments, Unit 2, Wootton Fields Farm, Marlborough Road, Wootton Bassett, Swindon, Wilts. SN4 7SA
01793 849430

[Old Crock]

Frankly, I'd be amazed if any off-the-shelf exhaust would simply bolt up to a vintage AC Six. I have had exhausts made for two different vintage AC's, and both required bespoke work, especially for the front pipes where bending is precise to suit the silencer mounting. The original silencer from the 1920's was a simple cylinder with two baffles (4932 below), which were discs with holes in them (see the photo from the parts catalogue below) Two long studs went all the way through from front (two pipes in) to back (one pipe out) so the box was capped each end (9009 and 9010). Very simple and relatively easy to make. Find the right chap in your area. You may well find a ready-made silencer to which you can attach the hanging brackets....but its the dual pipes at the front that require the work.

The exhaust downpipe gaskets are the same as a Triumph Spitfire (or Toledo), that's if your car has the three bolt flange, but many production vintage cars also had a two bolt.

[Big col]

Depends on your enthusiasm, workshop equipment and personal skill.
If all are good and you have a manifold already to work from then go to a local exhaust suppliers after a quick measure up and ask to walk round and look at what they have. There is always some really inexpensive bits that can be chopped and mated to make up a system.
If all are lacking and you are looking for a top notch full flow system including shaped manifold and down pipe and you live close to Leeds then try TLE (Tony Law Exhausts). (Sorry don't have a link).
If you want a slightly less expensive option but still done by others then you could get to know a friendly independent exhaust fitter. He may fancy something a little different than the usual humdrum Corsa or Focus and see it as a bit of a change to expand his horizons and find it interesting to cobble something up.

[jonto]

Made up this silencer for my 4 cyl, built up oversize the cast iron ends and used them as patterns to cast new end pieces in bronze, the body is stainless tube, through bolts stainless bar, nuts at each end. Instead of fitting baffles, I have the tail pipe extending into the silencer interior about half the length of the silencer, with the end plugged and small holes, perhaps 3/16" drilled around the pipe diameter, enough to equal the pipe section area. You can experiment with more or less holes if you wish, as this has some effect on the mixture. Your on SU's, remember the jet adjustment is for slow running only, changing the mixture on throttle open requires new needles to a different taper. I have a nice "ring" to the exhaust note and its not to loud.

[galfredus]

Dear all,

Many thanks for your advice on this.  It's often the things that appear the simplest which turn out to be the hardest.  It's no great surprise though - the things that were missing when I bought the car seem to be the things which are hardest to find!  I certainly do not have the pipe bending facilities or fabrication skills needed to do this myself. Will have to look into bespoke options I think.

The car isn't currently in my possession so I can't check details.  I take it the silencer is mounted towards the front of the car where the twin pipes from the manifold bend under the bulkhead?  Can anyone provide me with the dimensions (length/diameter) of the silencer?

Many thanks,

Geoffrey

[Old Crock]

Wow, Jonto, that is one potentially 'prize-winning' silencer!

Galfredus, re your last posting. See photos attached, you can download and enlarge:

(1) shows a silencer on an AC Six, front end. Clearly not a new one, nor a direct copy of an original, this had a hole in it but it shows the mountings and the positioning on the chassis (relative to other parts and fittings) 

(2) Rear view

(3) poor sketch, but shows all (rough) measurements that I used to replicate an original silencer

[galfredus]

Many thanks Old Crock, that's exactly what I needed.

Thanks!

Galf