"Clamshell" exhaust manifolds
"Clamshell" exhaust manifolds
(OP)
Hi,
Does anyone know anything about this type of exhaust manifold, like manufacturing methods and construction techniques used to make it or the benefits of a dual-walled manifold (pictures dont reveal but it has a second 'skin' within, and an apparantley consistent air gap between the two). Has anyone ever worked with these, have specs? I am only familiar with cast exh manifolds and am curious.
googling yielded only unrelated designs.
The pictures (have more if needed):
h ttp://i26. photobucke t.com/albu ms/c135/mo shimasu/cl amshell/DS C_0517.jpg
h ttp://i26. photobucke t.com/albu ms/c135/mo shimasu/cl amshell/DS C_0524.jpg
Thanks in aticipation,
Alex
Does anyone know anything about this type of exhaust manifold, like manufacturing methods and construction techniques used to make it or the benefits of a dual-walled manifold (pictures dont reveal but it has a second 'skin' within, and an apparantley consistent air gap between the two). Has anyone ever worked with these, have specs? I am only familiar with cast exh manifolds and am curious.
googling yielded only unrelated designs.
The pictures (have more if needed):
h
h
Thanks in aticipation,
Alex





RE: "Clamshell" exhaust manifolds
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: "Clamshell" exhaust manifolds
But I wonder at the problems of differential expansion if the whole thing were to be welded into one piece. There would at least need to be a slip joint around the outlet pipe, or perhaps some concertina wrinkles strategically built into the shape.
RE: "Clamshell" exhaust manifolds
RE: "Clamshell" exhaust manifolds
They are becoming more popular as emissions reduction during the open loop portion of afterstart and warm up becomes more of a constraint to passing an emissions drive cycle.
MS
RE: "Clamshell" exhaust manifolds
RE: "Clamshell" exhaust manifolds
ht
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http://i26
http://i26
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thanks for looking.
RE: "Clamshell" exhaust manifolds
MS
RE: "Clamshell" exhaust manifolds
RE: "Clamshell" exhaust manifolds
A heavy cast iron manifold made from several kilograms of iron, when stone cold, will continue to draw the heat out of the exhaust gas for a considerable time until it reaches "normal" operating temperature. Initial temperature rise at the cat will therefore be slower with a heavy cast manifold.
RE: "Clamshell" exhaust manifolds
Cheers , Pete.
RE: "Clamshell" exhaust manifolds
Flanges: WaterJet, Laser cut, Punched, Flattend if nessesary
Inner Skin: Either Drawn (two halves) or fabricated tubes ie header. Mig, Tig, or Laser seam welded.
Filler: Knitted ss wire cloth, or possibly packed wire mesh used with a form.
Outer skin: appears to be a Stamping (two halves), possibly would not have to have solidly attached to inside tubes as they are surrounding them and there is a filler in between to dampen any forced vibrations. Could possibly be spot or projection welded over the insides.
There are lots of possiblities / strategies to attach the outside skin. You would have to evaluate cost vs durability on that one.
Don
RE: "Clamshell" exhaust manifolds
RE: "Clamshell" exhaust manifolds