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View Full Version : Pipe Design 2.0 - for an 84/85 tecate



RubberSalt
01-31-2013, 04:58 PM
It's time for my 2nd Pipe build. *For those of you who remember this horror story (http://www.3wheelerworld.com/showthread.php/130209-Pipe-Design-!!Pictures!!-on-page-4!-Nasty-fast.?highlight=pipe+design)
This time, it's for my Tecate. I've got a kx250 jug with stock port timing. Everything is measured out, It'll need a few small adjustments.
I've got a 126 degree transfer, 186 exhaust port timing. I'll stick with this unless advised to change it.

This is my current design. The BMEP is making me think a little bit. It's also has a somewhat narrow powerband. I may go for a slightly wider set up. My current compression is 190 PSI in Wichita KS. Elevation should cause the BMEP to change, no?

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162070

*** On a side note. I had a 20g steel, a 110v mig welder and a slip roller now lol

RubberSalt
02-02-2013, 09:59 PM
I decided to go with a 70hp 13.79 BMEP 9250RPM beast!!

legacy51
02-02-2013, 11:21 PM
Thats the spirit! What software are you using for figuring port timing changes?

RubberSalt
02-06-2013, 12:07 AM
Porting Calculator v4.2.2

I'm not going to adjust the port timing much. The exhaust will stay, the Transfers may get raised to 127 or 128. This piston hits 4000 feet per second at 9435 RPM, possible ring flutter with 1mm rings at 9300 RPM. It does need a little bit wider exhaust (above the transfers) and the intake needs to be a little bigger - taller ports.

After some careful consideration, 12.34BMEP is much safer. The Pipe above and the 13.79 wont work for the KXT jug. So I'm going to build 2 pipes. 1 for the KXT 250 jug, and then later, the KX cylinder... Designed for e85:)

For the time being, I'm going to go with this. I can use/cheat and stick a base gasket in .25mm thicker and raise the ports. Transfers would go to 127.1 and exhaust to 186.9

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RubberSalt
02-06-2013, 03:29 AM
I've got this neat little program than can divide a cone into segments... Well. Here's a screen shot. My slip roller only does 12inch sheets at a time. This is useful for breaking segments longer than 12inches down.

I've got another piece of software that is useful for printing cone templates out in full scale. I 'll get some of them made up and post. It can help with designing fluid bends in the pipe. This is going to be out of frame drag style pipe :)

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RubberSalt
02-06-2013, 03:34 AM
I use this program to determine tuned length and heat of a pipe.

700 is close to the limits for gasoline. This doesn't calculate other fuels.

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ezmoney1979
02-06-2013, 11:57 AM
Nice work! I can't wait to see more progress, hand made pipes rule!