Can this program be used to calculate timing duration for chainsaw engine?

[PerkinsPowered]

Does anyone use computer program for calculate port timing durations for chainsaw engines?

"Rexxys mopedprogram" works great for 2-stroke engines with expansion chamber exhaust.

Can it also be used for engines with "back pressure exhaust" ?


Here i inserted numbers for Husqvarna 254, year: 87

 

[Yotaismygame]

But why?

 

[buttercup]

But why?

Ideal exhaust opening for a two stroke high performance engine;

Di := 2 ⋅ 2.03 ⋅ ccm
Example: 20ccm:
Di := 2 2.03 ⋅ 20
Di = 12.744 mm

 

[Yotaismygame]

Are you saying to eliminate any guess work?

 

[buttercup]

Yes I do.

 

[buttercup]

Are you saying to eliminate any guess work?

I will explain the crow tows when I'm sober if you interested. I have to look in to it. Not able to do it myself but you are certainly capable of doing it.

 

[PerkinsPowered]

Could theese numbers be fair for a woods ported saw;