Pipe Building

[2 strokes 4 life]

Anyone here have any experiance with building 2 stroke pipes? I needed a metal work project for school so i decided a pipe would be a challenge. It so far has proven to be very hard. Instead of your average pipe i have made mine out of 16 Gauge steel. I am also making a series of small ringes instead of peices of shaped sheet metal. So far i am just a little into the begining of the header.

If anyone has any advice that would be great. THANKS!!!

 

[Dave]

A two stroke pipe is a pretty advanced metal working project. This book will help - a lot.
http://www.fournierenterprises.com/cart/product.php?productid=16134&cat=1&page=1

 

[Rick]

Give this a try: http://www.buildandclick.com/

 

[SpeedyManiac]

Personally, I think a better project for a metal working class would be a pipe cage that bolts to the frame.

Good luck!

 

[nhrider]

Personally, I think a better project for a metal working class would be a pipe cage that bolts to the frame.

Good luck!

that sounds good.

 

[Skidad]

Personally, I think a better project for a metal working class would be a pipe cage that bolts to the frame.

Good luck!

Yup, cool idea there Speedy

 

[2 strokes 4 life]

I wa thinking about a cage but it would look bad and collect lots of trail debrie. Thats 2 stroke pipe building program looks sweet.

But i found out today i can not wled very thin metal on our mig very well. I might try to braze it together.

I wounder if it would be easier to build the pipe stright and then bend it?

 

[Rick]

You might want to get in touch with Steve @ MotoWest he can point you in the right direction.

 

[Steve@Motowest]

You're on right track with the small rings, that's called a cone pipe. That's all we had back in day and that's how the best pipes are still made today.

Back then, long before there were published formulas it was all trial and error. I remember watching Daryl Bassani and Donnie Emler beating and banging and sweating over pipes seemingly forever, always trying to make them better.

Now the easy way is to start with an existing pipe and just keep modifying it to produce the power you want. The Motowest pipe went into production after about three days of testing and only 2 prototypes being built. Once you have a working prototype you then use it to make the stamping dies and jigs to go into production with.

Today the specs have become so standardized... Be it mx or enduro or road racing, for any engine size and intended usage there's about 2 or 3 standard set of pipe measurements to choose from. Just twist and turn those measurements around and through the motorcycle of your choice and you have an exhaust system.

Although the science of 2-stroke exhaust design still lives on, the art of 2-stroke exhaust design has been all but lost. It's a bit of a shame really.

 

[Rick]

Steve,

Since were on the subject of 2 stroke pipes, I have a question for you. What is gained by shorting the head pipe, from the exhaust flange to first bend? What type of gain if any would one expect? Lowend, midrange or topend increase?

Thanks

 

[2 strokes 4 life]

Thankyou very much. When doing the cones is it easier to make a straight pipe and then bend it or use a cones that are cut the right angles?

Also Steve how does the power of your pipe compare to the FMF Gnarly on a EC250 power wise, and how much does it cost?

Thanks for all the help.

 

[Steve@Motowest]

Steve,

Since were on the subject of 2 stroke pipes, I have a question for you. What is gained by shorting the head pipe, from the exhaust flange to first bend? What type of gain if any would one expect? Lowend, midrange or topend increase?

Thanks

A longer head pipe gives more low-rpm torque and a flatter hp curve. A shorter head pipe will give you a steeper hp curve and will rev quicker. If you want to do some testing first start by replacing the left side powervalve cover with a flat plate. That's a small dose of the same thing.

 

[Steve@Motowest]

Thankyou very much. When doing the cones is it easier to make a straight pipe and then bend it or use a cones that are cut the right angles?

Also Steve how does the power of your pipe compare to the FMF Gnarly on a EC250 power wise, and how much does it cost?

Thanks for all the help.

Start with a bunch of 1-2 inch straight cut cones and then trim them or overlap them to make the curves.

Our pipe was really meant for mx, it just hit and pulled harder all the way up the hp curve. I was surprised that so many enduro type riders liked it.

Cost...? We don't have anymore of them.

 

[Rick]

Steve, so, if you had a section of the headpipe cut out, (Messico Pipe) and installed an LTR P/V Cover would there be any thing to gain from this mod? Since the P/V Cover helps w/ lowend, and the shorter headpipe increases mid would the 2 mods work togther?

Thanks

 

[Steve@Motowest]

More likely they would just cancel each other out. The powervalve cover is part of the header pipe.

 

[Rick]

Steve,

Thanks for the info

 

[WoodsRider]

Our pipe was really meant for mx, it just hit and pulled harder all the way up the hp curve. I was surprised that so many enduro type riders liked it.

I put a Motowest pipe on my '98 EC250 and it did hit quite a bit harder than the stock Messico. After waffling the stock FMF pipe on my '01 XC300 I put the Motowest pipe on that bike and could never really tell the difference between the two.

What I really liked about the Motowest pipe was that it was made from heavier gauge steel and tough. In six years of crash-testing that pipe only has one ding and has never been bent out of shape. Can't say the same for the three FMF pipes hanging in my garage.

 

[2 strokes 4 life]

Thansk for all the help.

 

[Cruiser]

I had bothe the motowest, well one of the prototypes apparently, and the FMF,, the motowest was better,, had more low down and even tho it had a real hit,, it came on smoother than the FMF.. The FMF felt like a true MX pipe,, less bottom,, hard hit and signed off early.. I still have my MW pipe,, but its almost crushed beyond use.. I'm thinking my winter project it to bring it back from the dead.. and mount it back up to my 97 ec 250.. going 2-stroke DS bike with that one..