W
william42
Guest
For those that never learned geometry in school...
No, there is no such thing as an 80 Cubic Centimeter 2-stroke engine in the bike engine context.
Engine Cubic Centimeters (cc) DISPLACEMENT is measured in a cylinder by geometry math.
The Volume of displacement is measured by the Bore width in centimeters of the cylinder * the Stoke length in Centimeters the piston can travel, period.
The simple volume that can be displaced with the pistons movement in the cylinder.
The head is where all the 66 Cubic Centimeters of compressed air/fuel mixture is shoved into and ignited.
The smaller that area, the higher compression ratio and usually, the bigger the bang (power) you get.
Most 66's are like 8:1 compression, that puts the heads CC size ~8.25cc give or take how your measure it, but regardless of size, the head IS NOT part of an engines displacement number.
That is the Compression Ratio and what matters when the 2 numbers are combined.
And just because something can displace more fuel mix does not make it stronger or better... All that is decided in the head by compression and spark timing and measured in any numbers of ways like Horsepower or Kilowatts.
Heck, a 48cc sent up right with an expansion chamber and such will run with a stock 66.
That's what really irritates me about the marketing BS specs and try to get others not to go along with it.
So what is the actual Engine Cubic Centimeters of a 49cc china motor, or 66cc