2 stroke exhaust

[Joe Llamahead]

I'm getting my parts and plans togeather to repower a Chinese buggy with a Arctic Cat 500cc 2 stroke twin.
I have driven this sled on a gravel road and It runs just fine for a sand Buggy. it looks like the engine will have plenty of room to fit. I might be able to reuse the origional expancion chamber but it would look cobbbled togeather if i did and I prefer my buggy not look like afterthought ( even if it its true)

I know the pipe shape and size does influence torque and hp power band ect. I'm sure there is math formulas to build expancion chambers to run the way we want but i don't know where to look? Any Info out there?

[PilotHawK]

You should be able to reshape the pipe and it not look too bad if you can weld/braze halfway decently. The trick is to not change the length of the pipe. You should be able to cut and rotate the pipe however you need, but if you need to change the angle of the bend make a perpendicular cut across the pipe. On the side of the pipe you need to tighten the radius on, remove a wedge shaped piece that will give you the amount of change you need then reverse the piece and install it 180 degrees from the original position of the cutout. This will give you the new angle that you need without shortening the pipe.

[K-fab]

Do just as PHawk says - stick w/the stock pipe and modify it to fit.

See if you can find a picture of any of the early 1980's factory motocross bikes. They used individual cone, hand built pipes that were works of art. Study the pix of the pipes and you'll get the idea of how/what to do with your stock sled pipe.

[odypilots]

If you're willing to spend the money, you could do what we did, which is to find a pipe builder that specializes in making pipes for your engine. The outcome will look MUCH better than modifying the stock pipe, and should work as well or better.

[trojan]

A quick google got me this

http://members.bellatlantic.net/~vze...nes/engine.htm

[PilotHawK]

That page is a great find!

[weasel]

Blair made my head hurt last time I read his stuff,, But,But I do have an internet copy of the Gordon Jennings book that is a much better read.

still make's my head hurt tho, but I did use the Jennings book in my last hobby, R/C nitro boats. Had a couple 3.5cc outboards that went over 60mph on a 28.5 inch O/B tunnel hull.
weas head

[renegadespec1]

Geeze....
It's too bad we don't have anybody on this board who rolls up pipes...or has the program for figuring max output of said pipes...or has rolled a set for his wife....Damn I need to figure out how to get the smiley's back

[weasel]

The hard part in building 2 stroke pipes is knowing all the data from each individual engine. The list is large, even on one simple single cylinder nitro engine. TSR has a premier program for structuring the actual pipe dimensions but then we have to configure it to fit our machine, whatever that may be. Not a very profitable buisness in a world that don't want two strokes much anymore.

[trojan]

Originally Posted by renegadespec1

Geeze....
It's too bad we don't have anybody on this board who rolls up pipes...or has the program for figuring max output of said pipes...or has rolled a set for his wife....Damn I need to figure out how to get the smiley's back

Mate, I roll-up and pipe but I doubt it will help.
By 'rolled a set for his wife', do you mean got a mate to roll up a set and traded his wife for them, ok then.

In the link I gave there is an interactive java program that may be what you're after
JavaPipe: Tuned Pipe Designer
If it dosen't work for you, get a decent browser like firefox