Expansion Chamber

Could one of you guys tell me the inside diameter ot these tuned pipes.I need to know how big it is wear the header slides in.I have a friend that has a supplier
that sells pipes with extreme bends for industrial uses plus he is an excelent welder.
 
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Ghost0 said:
Well just to clarify, the use of the 3/4 copper fitting that fits over the pipe means that the outside diameter of the pipe is 3/4. So the inside diameter of the pipe is less. Just remember steel and copper tube have their own set of standards and ways of measuring. I am pretty certain that if you find steel tubing that has a 3/4 outside diameter then that is the one you want. The wall thickness of the pipe is around 1/16 of an inch. Hope this helps.
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On my installation that is NOT correct. I used 3/4" plumbing copper. Plumbing copper is measured inside diameter. The outside diameter of the copper is 7/8" as is the outside diameter of the chamber, so the INSIDE diameter of the copper COUPLING is 7/8". The copper coupling was a very good fit on the chamber, but a bit loose on the header (original muffler header).
 
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misteright1_99 said:
On my installation that is NOT correct. I used 3/4" plumbing copper. Plumbing copper is measured inside diameter. The outside diameter of the copper is 7/8" as is the outside diameter of the chamber, so the inside diameter of the copper COUPLING is 7/8". The copper was a very good fit on the chamber, but a bit loose on the header (original muffler header).
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Actually I agree - plumbing copper is ID. My copper coupling was a bit loose on the little header, so I tried to expand it a bit (probably didn't make it much larger), then I roughed both piece up, but didn't remove any material - then I used some $2.99 exhaust system sealer gooze (I'll find the brand and such when I get home) to slip them together nice and snug. Seems to be holding well.
 
Cool Thanks Paul, I have JB Weld on it now, it has held for about 50 miles. If it fails I am going to weld it... It cant fail and fall off as I have a support under the pipe as well as a hanger on the chamber. I will just keep and eye on the header to pipe seal....
 
Sorry for the misleading, and now deleted, incorrect information. I was going from memory and well, apparently my memory isn't very good.
 
Well I finally got the drill bit I needed and drilled the jet out 1 size to .028 #70. I took it out about 10 miles this morning and it made such a difference. I got rid of the top end sputter, and picked up 1 mph. I still have a midrange sputter, that I believe is the taper of the needle, but its not where I usually cruise so I am not going to try to retaper the needle. When it cools down I still have to pull the plug and look at it, but I am confident that I am there. The pipe is quite a bit louder than stock, and I have put some steel wool inside the baffle in the silencer to to try to force more exhaust around it thru the fiberglass and back into the baffle and out the stinger, rather than having a strait path out, and made quite a difference....

Got it all painted with high temp paint and am ready for summer.....
 

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It is supposed to absorb the pulses from the engine and improve the performance. I bought it on a whim, and didnt notice much improvement.
 
someone needs to make a thread (and sticky it) for a step-by-step how-to for porting the exhaust and manufacturing an expansion chamber. with a complete list of tools and supplies needed.
 
MrLarkins said:
someone needs to make a thread (and sticky it) for a step-by-step how-to for porting the exhaust and manufacturing an expansion chamber. with a complete list of tools and supplies needed.
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Actually manufacturing an expansion chamber would be very interesting.

I can cover adapting a pocket bike chamber and opening the manifold.
 
Ilikeabikea and I did a live video on this forum a while back on making cruisers pipe not many watched and I think it was too boring.rotfl
No link it was a live show and not taped.
Norman
 
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I just put this tuned pipe from a mini crotch rocket on and it is the bomb.
I had to braze a bracket on the back, and bolted it to seat post clamp.I took a rubber hammer and made a small dent so it would fit frame a bit closer.The header pipe was slightly off so i heated it up and pulled it out .It is a nice looking pipe and it sounds really nice as well.I had it up 36.2 mph on flat ground and it is very smooth.
 

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