My 2-stroke spreadsheet is ready (for now at least), so I'm throwing it on the net so everybody can use it.
It contains pages for ports, the head and FOS pipe
On the seperate ports pages (exhaust and transfer), it calculates the STA numbers (Specific Time.Area) of your ports and you can matcch them to the target's, determinned by the BMEP
On the Head page, you can design your head and it calculates the MSV (Mean Squish Velocity) 100% accurtly with Blair
On the FOS-pipe page, it calculates a Frits Overmars FOS pipe, and you can ad a Wobbly-duct , and you can add extra header/diffusor/baffle sections to the pipe.
And you can print the final portmap to scale, so you can cut-out the ports, stick in in your cylinder and see where you'll need to grind some more.
you are free to do with it what you want, as long as it is not for commercial use. If somebody has idea's to improve or add extra features, please share so we can all benefit.
In the manual I've tried to explain how it works, please read it first before you ask questions.
25/12/23 :
I've changed my FOS-exhaust page, so it includes the header and diffuser %'s, and some other changes.
excel : https://greentrade.international/Janbro ... ke2.0.xlsm
doc : https://greentrade.international/Janbro ... ke2.0.docx
and a stand alone Exhaust, which has an extra exhaust-comparator sheet
https://greentrade.international/Janbro ... E_3.0.xlsm
