Exhaust diameter

[matty40s]

 

The most practical solution I have come up with to repair this none standard cracked stainless steel concertina bit is to replace the whole concertina and pipe above with a 12" braided concertina and two adaptors. This section is immediately below he hospital silencer.

This reduces the diameter of the pipe from 2" to 1 1/2" for this section.

 

Would there be any noticeable difference to the engine running and what would the effect of this be if any??

[Albion]

 

The most practical solution I have come up with to repair this none standard cracked stainless steel concertina bit is to replace the whole concertina and pipe above with a 12" braided concertina and two adaptors. This section is immediately below he hospital silencer.

This reduces the diameter of the pipe from 2" to 1 1/2" for this section.

 

Would there be any noticeable difference to the engine running and what would the effect of this be if any??

 

What about something like this? Flexi coupling

Couldn't that be adapted/welded?

Roger

[Grace and Favour]

 

 

 

I like the wine rack you're building against the bulkhead - - - - - But it's empty!!

[MtB]

What about something like this? Flexi coupling

Couldn't that be adapted/welded?

Roger

 

I have that exact component welded into the exhaust on Aldebaran (single cylinder Kelvin engine). It's what I was attempting to describe Matty the other Sunday after the banter!

 

But to answer your question, from my own experiments reducing the 2" BSP exhaust on Aldebaran with a 1½" BSP silencer, it made no difference whatsoever other than making the engine WAY to quiet. The engine didn't seem to mind at all and its 3.75 litres in a single cylinder. Yours I'd imagine is about the same capacity spread across two cyls so will be less picky about exhaust diameter.

 

But why not use this (aprt from cost)? It is just plain plumbing to incorporate it into your exhaust and WAY more flexibility which is what you need given the location 'straight up' of the roof conection.

 

http://www.midlandchandlers.co.uk/products/engineering/exhaustsystem/bellows/exhaust/ea099.aspx

 

Or THIS looks awfully like the bellows you have now

[Timleech]

 

 

Would there be any noticeable difference to the engine running and what would the effect of this be if any??

 

1.5" bore is only just over half the cross-sectional area of 2" bore. I'm pretty sure that 2" is specified as the minimum acceptable bore for a 2L2 exhaust. When the engine is working hard you might very well suffer from reduced power, smoking, and excessive temperatures in the exhaust system. OTOH it might all work perfectly.

 

Tim

[MtB]

 

The most practical solution I have come up with to repair this none standard cracked stainless steel concertina bit is to replace the whole concertina and pipe above with a 12" braided concertina and two adaptors. This section is immediately below he hospital silencer.

 

On reflection, are you sure your exhaust is 2" bsp in the first place? I don't rememeber it being anything like as big as the 2" bsp exhaust on Aldebaran. I reckon yours is 1.5" bsp.

 

 

This reduces the diameter of the pipe from 2" to 1 1/2" for this section.

 

Are you measuring the external diameter when you get 2" diameter? 1.5" bsp is about 1.9" external diameter.

http://www.tubesfittingsvalves.co.uk/BSP%20pipe%20sizes.htm

[Timleech]

On reflection, are you sure your exhaust is 2" bsp in the first place? I don't rememeber it being anything like as big as the 2" bsp exhaust on Aldebaran. I reckon yours is 1.5" bsp.

 

 

If that's the case & he's considering reducing the size below 1.5" bore then yes I'm sure it will affect performance in one or more of the ways that I've described.

 

Tim

[MtB]

Hang on, cancel all that. Aldebaran has a 2½" bsp exhaust!

 

Durrrr....

 

(My reduction experiments were reducing it to 2")

[matty40s]

On reflection, are you sure your exhaust is 2" bsp in the first place? I don't rememeber it being anything like as big as the 2" bsp exhaust on Aldebaran. I reckon yours is 1.5" bsp.

Are you measuring the external diameter when you get 2" diameter? 1.5" bsp is about 1.9" external diameter.

http://www.tubesfittingsvalves.co.uk/BSP%20pipe%20sizes.htm

 

I think the cocktail sticks holding your eyes open after the banter must have affected your vision !!

 

 

This afternooneys work...

The pipe nearest to the camera is the cracked one, I have sliced it off and taken 3mm off the cast bit in the middle.

I ground away the welds on this piece and contoured it so the reducing unit on the far away pipe can slip on and be welded in place.

[GUMPY]

Have a read of this

http://dba-the-barge-association.222578.n4.nabble.com/Exhaust-overheating-nightmare-help-sought-td240730.html

http://dba-the-barge-association.222578.n4.nabble.com/Overheating-exhaust-nightmare-update-td240681.html

 

Could be worth bearing in mind when going for a reduction in size.......

[matty40s]

Have a read of this

http://dba-the-barge-association.222578.n4.nabble.com/Exhaust-overheating-nightmare-help-sought-td240730.html

http://dba-the-barge-association.222578.n4.nabble.com/Overheating-exhaust-nightmare-update-td240681.html

 

Could be worth bearing in mind when going for a reduction in size.......

 

Thanks for that,interesting stuff. After all that it wasn't the reduction that caused the problem but will look for reduced peformance. I will see how i go with the new set up.