Vintage Minor Register

I am making up an M type exhaust system, not being a purist, I propose to use a modern silencer/expansion box.

I have a most useful and tolerant exhaust specialists locally who can normally find a modern box of approximately the correct dimensions and type.

Was the original a straight through expansion box or were there baffles?

Any suggestions of a modern box that anyone has used?

David.

If you were being purist you wouldn't have much luck since the original silencers haven't been available for many decades. It seems two makes were supplied, Burgess and Vortex. I don't know how the Burgess is made or what one looks like, but the Vortex appears in many period photos. I have just had one repaired just to hear what it sounds like; I intend to take it off again and cut it up so that I can make a new one.
It has not been on long but I now know it is about as effective as the straight-through it had on before but much quieter. As the name implies, it contains a series of interlocking cones which induce a vortex. It is much larger than the silencer supplied by S+V. I will take some measurements later on and post them.
I'll see if I can include a photo - my attempts so far have been 'invalid'!

Ian just sent in this picture of his Vortex. The other three images were sent to me by Ian in 2006 and were published in M 124.

Looks like quite a complex piece of kit to replicate - more like a wind instrument than a silencer!

Minors were fitted with conical-ended silencers that had much simpler internals, and replicas are available from the Cooke Group.

Ian, thanks for putting those photos in. I had forgotten about the earlier ones. For anyone looking for a similar sized one, the length of the barrel is 15" and the diameter 4.5".