2101 porting and pipe design

[Grits & Gravy]

I'm building a 2101xp just for a toy and want too fabricate a pipe for it, problem is I have no idea how too go about designing one.

I am a CNC machinist/prototype fabricator in the aerospace/military industry so I have the tools and the skills to fabricate the pipe with no problem whatsoever and can do so out of just about any type of material imaginable.

I have several jugs at least one of which is going to get a big bore kit and a billet head... all of my jugs are unported and stock right now so they can be matched up too the theoretical timing of the pipes design. I have been building billet 2-stroke stuff since the 250R days, just never built my own pipe.

Anyone on here interested in designing the pipe for me and providing printable templates that I can use for the pipe fabrication in exchange for some custom machine work?? Maybe you want a pipe as well?? I can build just about a billet anything within reason out of just about any material you want.

 

[mtngun]

I'm building a 2101xp just for a toy and want too fabricate a pipe for it, problem is I have no idea how too go about designing one.

Either Jennings' or Bell's book gives formulas and suggestions for pipe design. Though I've heard that state-of-the-art pipe design has changed over the years.

I seem to remember hearing about a free pipe design program or two on the web, though I've never tried them.

Here's one: JavaPipe: Tuned Pipe Designer

Some googling should also yield free programs to lay out the cones.

Good luck, and post pictures.

 

[Boleclimber]

Javapipe gives very poor results on chainsaws, I wouldn't use it. There is software you can purchase for pipe design.

I have used Bells formula's and have come up with good results.


Amazon.com: Two-Stroke Performance Tuning (9781859606193): A. Bell: Books

 

[husq2100]

it would be great if you share some pics of your work as you go

 

[trappermike]

I custom design expansion chambers,I already have designs for the 2100and 2101(And many other models),I can ship you the templates and lead pipe with instructions.
If you send me some engine specs,exhaust port duration and your planned power peak in rpm's,and type of power band you wish, I can custom design it for you.
You can call me at 1-250-597-1127 evenings,Pacific(Vancouver) time.
I also still have a supply of race carbs for 100cc saws.

 

[husq2100]

what carbs do you have for a 2100? gas or alky?

 

[trappermike]

I have gasoline carbs only,I don't bother working with alcohol motors.

I once built and modified a carb to run Nitro-methanol,it was a lot of experimenting and work,but I finally succeeded in getting it to work with a separate fuel pump(You need to supply 2-3 times the amount of fuel as gas).After all my work was done I found out that any fuel other than gasoline was not allowed in the B.C. Loggers Sports of that time,so the project was a waste,I couldn't use it.
But I still have the carb and fuel pump today,for nostalgia I guess...:msp_biggrin: