Can I use 5/8" square pipe for an exhaust?

tonyslowrider · Mar 10, 2012

I have a 4 stroke motor, the exhaust is 7/8" like a 2 stroke exhaust. But I want to use a 5/8" square pipe for a custom exhaust. I cut off the end of the 7/8" pipe that attaches to the motor, and welded it to the square pipe then bent the square pipe. Will it damage the motor or make it run bad? Or will it be ok?
Basically what I need to know is, will using a pipe that is slightly smaller than the usual exhaust pipe cause a problem with the motor? It is only a 2/8" difference.

GearNut · Mar 10, 2012

It will still run fine. The size is not sooo small so as to hurt the performance. Due to the fact that the pipe is square, the overall inner dimensions are very close to each other.

andrewflores17 · Mar 10, 2012

it should work fine i use gas line for a hot water heater for mine im sure yours will look better and be thicker than mine dont forget to post pics id like to see how it comes out

Ibedayank · Mar 10, 2012

never heard of square pipe most be hard to thread for fittings

can you post pics of said square pipe and some screw on fittings?

GearNut · Mar 10, 2012

All you gotta do is use multi split compression dies and 7 way overleaf expanding taps. The threads do look a bit unusual though.....

tonyslowrider · Mar 12, 2012

I'm going to post Pictures once I finish the project,my exhaust will be one of a kind.

fredgold52 · Mar 13, 2012

Yes, Pics Please. I'm really interested in seeing what you have done.

Where do you get 5/8 square pipe? Will it hook up to a standard toilet, or is a special square one required? All sorts of similar questions are rushing to my mind, but this is a 'G' rated board, most of the time.

dance1

tonyslowrider · Mar 14, 2012

I will post pics, but I've been very busy, I'm trying to get some pieces chromed but it's very expensive. So it will be unchromed but let's just say that it's one twisted exhaust,so give me some time. .shft.

turbo1889 · Jun 17, 2012

It's actually technically refereed to as "Square Tubing" not square pipe. It is for structural and/or ornamental applications. Square tubing generally being easier to work with then round tubing. Some people have even built their own frames from the stuff:

http://www.grainger.com/Grainger/ra...earchesinbase+true&Ns=List+Price|0&sst=subset

As for making your exhaust system from it, why not ! Should certainly look unique.

Dan · Jun 18, 2012

Oh this is cool.

Great thunk Tony. Looking forward to seeing this done.

Gonna really be a one of a kind.

scotto- · Jun 18, 2012

I was actually thinking of using some triangular tubing for an exhaust pipe.......it would need to be at least 1-3/8" for reasonable exhaust flow. I blew the exhaust pipe right off my HF 212cc at the race last weekend. It cracked on the outside of the weld to the exhaust flange. The bike had wicked backfiring when I let off the throttle going into the turns.

In order to race my Final, I had to tie-wire the pipe as best as possible using some aluminum can and tie wire. It held ok and I was able to finish the 12 lap race. It was a blast.....literally!

dnut

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Can I use 5/8" square pipe for an exhaust?

tonyslowrider

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