Guess what make ?

[grewth]

Any idea what make of pipe this is ?
It was fitted to my US import K4, but the cylinder head fixing is the F model/K7 type, the K4 stubs having been removed from the cylinder head.
There's no baffles whatsoever and no rear fixing point at present.
Mercifully, automotive exhaust components like perforated steel tube, and glass wool are as cheap as chips (but as soon as you mention motorcycle the price seems to double at least)
I need to weld on a mounting tab and fabricate a glass pack type baffle.
I'm assuming that the baffle should run the whole length of the large rear tube section.
What diameter perforated tube should I use for the baffle ?

 

[hinksy]

It looks yoshimuraish , does look as though it`ll clean up though

 

[grewth]

I've already cleaned it up once, with a P80 flap disc on a grinder.
Then I put it back on the bike to get it running, and left it on, outside in the weather.
Now I'm just wondering if they do VHT paint in a rust colour, so I'd never have to retouch it

 

[hinksy]

That scares me , my delkevic`s went brown even before I rode the bike . The headers have a fine rusty layer on them now that you can feel when you rub your hand on them . Cant wait till they get wet , not

 

[hinksy]

or

 

[grewth]

That sounds really good.
Is that a modern Yoshimura pipe then ?
So now all I need is for some kind person to open one up with a tin opener and measure up all the internals for me.
No, seriously, I'm very good at reworking and modifying tired old exhaust systems.
My old F1 ran a Frankenstein system made out of three different makes of 4 into 1 cut up and welded back together.
It ran and sounded really good too.
More by sheer luck rather than scientific design.
I built that about 1990 by my reckoning, and my skills have improved since then, although my appearance hasn't.

 

[Loki]

Start with perforated pipe same diameter as the mid pipe, there is a packing material available which swells with heat which makes it easy to insert then it swells, you'll need a closing infill to close off the gap between the perforated pipe and the "silencer"case. I used this in my Corvette side pipes and it worked really well, the previous owner had removed the baffles entirely and it was stupidly loud!

Loki

 

[grewth]

Start with perforated pipe same diameter as the mid pipe, there is a packing material available which swells with heat which makes it easy to insert then it swells, you'll need a closing infill to close off the gap between the perforated pipe and the "silencer"case. I used this in my Corvette side pipes and it worked really well, the previous owner had removed the baffles entirely and it was stupidly loud!

Loki

Thanks for that !
I've noticed that automotive exhaust components are stupidly cheap online, it's only when you mention motorcycle that somehow the price becomes a kings ransom

 

[hinksy]

You used to be able to buy inserts from the muffler producers . I think you can still get DB killers/inserts . You could maybe adapt one of them and like loki said try a car shop , but I have done my own over the years . When I had my priginal F2 in the 70`s , I put a 4 into 2 system on it from walker pipes . One of my mates at the time had the same bike with a 4 into 2 hanco system which sounded way better than mine . After doing some research ( dismantling ) we found the walkers had double skined headers like std and the perferated tube with packing . The hanco`s had thin wall stainless and no packing , but a muffler design like modern car mufflers where the exhaust gases have to do an S shape through the muffler . In the day you could buy them , so I did and swapped out the walker ones for hanco . Here are some pics of my delkevic`s setup . Although their muffler is non sevicable they have this tube that bolts in and forces gases into the packing/perforations