weenieroaster
ArboristSite Operative
If you guys studied holes so much, what is your learned conclusion?
If you guys studied holes so much, what is your learned conclusion?
They are nothing but trouble.
Andy they weren't filled with dirt until you got hold of them right?
Guys lets get back on track.
can you make 22hp with a sp125 on alky nitro!
If you guys studied holes so much, what is your learned conclusion?
If you don't widen the ports, tighten the squish, or do any type of research, maybe.:monkey:
Later,
My conclusion is that there are basicly 2 kinds.
Big old good uns, and good old big uns.
Andy
The chart does not have anything to do with the effect of turbulence on output, it has to do with the squish velocity, and when it occurs.
As for thermal efficiency, chainsaws are not ~25%.
You might want to take a read of "The High Performance Two Stroke Engine" Chapter 3, pg 45 and table 3.2.2, the just of it is thermal efficiency depends on the swept volume, and can range from 10-15% for very small engines to about 50% for large industrial engines. Chainsaws would fall in about 20% or a little less at best. You would need to be into about 1000 cc in a single cylinder engine or very high compression before a 25% thermal efficiency would be expected.
Here is a little tid bit of reading also. http://www.popularhotrodding.com/enginemasters/articles/hardcore/0606em_understanding_compression_ratio/index.html
The importaint part from the article:
I don't know what you are doing on mods that lowers thermal efficiency, but the way I am working at it I make every effort to turn heat into motive power and in that shoot for high thermal efficency.
What I like about Fred on this stuff is he questions everything, makes me double check stuff and dig deeper into stuff than I might otherwise do. .
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