hey guys i gota question about compression. stupid question but wat EXACTLY is compression, i think i gota idea of wat it is i jus wanna no wat exactly it is, and wut dus the ratio mean. like how do u interpret the numbers? (ex. 10:1) or sumthing. keep out all the flaming all im lookin for is answers

 

as far as i under stand it it is the ratio between the capacity at BDC (bottom dead center) and the capacity at TDC (top dead center) so 10:1 your combustion chamber is 10X large at BDC than it is at TDC

that help

and if im wrong some one pleez tell him other wise so i can be informed too

 

ok yea thats what i thought thanks . now for my other question...wats the significance of having higher/lower compression. wats the differences and what are the up's and down's of each.

 

higher compression will produce more power because it squeekes the gasses in the chamber more creating a hotter burn.

if you go with forced induction then you want to drop the compression because you are putting more air into the same size opening and if you don't drop the compression you will get pre-detonation (this is when the air-fuel mix burns on its own with out the spark plug (thats how deisles run) pre-detonation can rip an engine apart.