Flexible exhaust tubing

I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu

Stuart & Kathryn Fields wrote:

I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu



I did one a long time ago using elbows and pieces.
(Couldn't spend money on it, so)

To "measure" the pipes, I filled the sample pipe with water
and measured the volumn of water for each pipe.

Lengthen the short ones, shorten the long ones.

It was a bit of a hassle, but it did work ok.

For what it's worth...

Richard

On Tue, 8 Jul 2008 18:21:43 -0700, "Stuart & Kathryn Fields"
wrote:

I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu


hey stewie go down to the local electrical place and buy yourself 4
vacuum cleaners, or find a 'vacuums are us' and buy 4 replacement
flexible wands. they are plastic, are flexible and are the diameter
you need.

good luck on the chopper.

btw I have seen an RV6 that used 4 pipes into one with no muffler at
all. it was the quietest aeroplane engine I've ever heard. I dont know
what the trick was in the geometry but it used the same engine as you
are using. some amazing stuff is possible there.

Stealth Pilot

Stuart & Kathryn Fields wrote:
I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu



Nylon hose is cheaper. Shape it to where you want it, drill a 1/4" hole every few inches and pump it full of
Great-Stuff spray foam.

PVC tubing will also form fairly well if you warm it up good with a heat gun.

Clothes dryer ducting.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"Stuart & Kathryn Fields" wrote in message
...
I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned
exhaust for my 0320 Lycoming engine that I have mounted in my Baby Belle
helicopter. The idea is to have 4 equal length pieces attached to exhaust
flanges bolted to the cylinders, arrange the 4 pieces to intercept the
4-into-1 collector, coat the tubing with epoxy resin so that the shape is
maintained and then present these pieces to be copied by the exhaust
bender.

Stu

"RST Engineering" wrote in message
m...
Clothes dryer ducting.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"Stuart & Kathryn Fields" wrote in message
...
I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel
is acceptable. I want to use it for a model of the headers of a tuned
exhaust for my 0320 Lycoming engine that I have mounted in my Baby Belle
helicopter. The idea is to have 4 equal length pieces attached to exhaust
flanges bolted to the cylinders, arrange the 4 pieces to intercept the
4-into-1 collector, coat the tubing with epoxy resin so that the shape is
maintained and then present these pieces to be copied by the exhaust
bender.

Stu

To date I've tried flex conduit, both steel and aluminum and both sag like
crazy and change lengths easily and don't hold their shape. Heating and
bending PVC pipe is such a cut-and-try process which also produces some
fumes off the PVC that is not supposed to be nice and the use of elbows and
saw cuts is kind of workable and I have a set of 4 equal length pieces that
have been shaped to do the job but the thing looks like crap and the exhaust
is really open for view on this helicopter. Hopefully the flex exhaust
tubing will hold its shape when bent by hand long enough for me to coat it
with epoxy to lock in the shape and hold it for a trip to the exhaust tube
bender guy.
The trick that I'm counting on, and it looked possible when I was using
conduit, is to connect the tubing to exhaust flanges bolted to the cylinders
and position all 4 pieces to intercept the 4-into-1 collector at
approximately the same time and counting on the flex tubing to hold its
shape and length, long enough for some epoxy to sieze the flexables even
further. The idea then is to remove each piece and have it matched.
I've tried AutoZone, Pep Boys, Napa, and JC Whitney. McMaster-Carr, Toys 4
Trucks, Whitney does have some SS flex but at $30 each 5' piece. This would
run the cost up a bit. I hope to finde some galvanized steel flex somewhere
at a lower price.
Stu

"cavelamb himself" wrote in message
news
Stuart & Kathryn Fields wrote:

I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel
is acceptable. I want to use it for a model of the headers of a tuned
exhaust for my 0320 Lycoming engine that I have mounted in my Baby Belle
helicopter. The idea is to have 4 equal length pieces attached to exhaust
flanges bolted to the cylinders, arrange the 4 pieces to intercept the
4-into-1 collector, coat the tubing with epoxy resin so that the shape is
maintained and then present these pieces to be copied by the exhaust
bender.

Stu

I did one a long time ago using elbows and pieces.
(Couldn't spend money on it, so)

To "measure" the pipes, I filled the sample pipe with water
and measured the volumn of water for each pipe.

Lengthen the short ones, shorten the long ones.

It was a bit of a hassle, but it did work ok.

For what it's worth...

Richard

Thanks for the tip on measuring the pipe length using water. Neat.

Stu

"Stealth Pilot" wrote in message
...
On Tue, 8 Jul 2008 18:21:43 -0700, "Stuart & Kathryn Fields"
wrote:

I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned
exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle
helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges
bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1
collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu


hey stewie go down to the local electrical place and buy yourself 4
vacuum cleaners, or find a 'vacuums are us' and buy 4 replacement
flexible wands. they are plastic, are flexible and are the diameter
you need.

good luck on the chopper.

btw I have seen an RV6 that used 4 pipes into one with no muffler at
all. it was the quietest aeroplane engine I've ever heard. I dont know
what the trick was in the geometry but it used the same engine as you
are using. some amazing stuff is possible there.

Stealth Pilot

Interesting idea If the flexible wands hold their shape to a reasonable
degree we may have a solution.

Stu

On Jul 8, 6:21*pm, "Stuart & Kathryn Fields" wrote:
I'm looking for a source of 1 1/2" flexible exhaust tubing. *Mild steel is
acceptable. *I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu

http://www2.cip1.com/ProductDetails....ode=C13%2D3499

Aluminum "wrinkle belly" tubing should hold it's shape nicely. This
stuff is a little oversize. Great Plains Aircraft Supply carries this
stuff too, if you want to support an aviation vendor.

flybynightkarmarepair wrote:
On Jul 8, 6:21 pm, "Stuart & Kathryn Fields" wrote:
I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel is
acceptable. I want to use it for a model of the headers of a tuned exhaust
for my 0320 Lycoming engine that I have mounted in my Baby Belle helicopter.
The idea is to have 4 equal length pieces attached to exhaust flanges bolted
to the cylinders, arrange the 4 pieces to intercept the 4-into-1 collector,
coat the tubing with epoxy resin so that the shape is maintained and then
present these pieces to be copied by the exhaust bender.

Stu

http://www2.cip1.com/ProductDetails....ode=C13%2D3499

Aluminum "wrinkle belly" tubing should hold it's shape nicely. This
stuff is a little oversize. Great Plains Aircraft Supply carries this
stuff too, if you want to support an aviation vendor.


I have seen such ducting in paper also which would make epoxying it
into shape easier. Try J.C. Whitney, they used to carry it.

Dan, U.S. Air Force, retired